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466 Cards in this Set
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Describe some of the causes of Intracellular Edema of the brain. |
Dysfunctional Na+/K+-ATPase pump (e.g. hypoxia), and Hyponatremia causing osmotic shift. |
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Explain some of the causes of Extracellular Edema of the brain.
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Extracellular edema of the brain is most often due to increased vessel permeability, acute inflammation (e.g. meningitis, encephalitis), metastasis, trauma, lead poisoning, repiratory acidosis, hypoxemia |
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Explain why a patient with head trauma is purposely hyperventilated? What physiological reaction does it produce in the brain tissue? How does this help?
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A patient wit head trauma is purposely hyperventilated to produce respiratory alkalosis, which causes cerebral vessel constriction. This decreases the risk of increased vessel permeability and cerebral edema.
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How do respiratory acidosis and hypoxemia lead to cerebral edema?
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Respiratory acidosis and hypoxemia cause vasodilation of cerebral vessels, which increases cerebral vessel permeability, resulting in cerebral edema.
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Describe some of the signs of increased intracranial pressure.
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Papilledema (swelling of the optic disk), headache, projectile vomit without nausea, sinus bradycardia, hypertension, signs of cranial herniation.
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What is Pseudotumor cerebri? What is it caused by? Describe some of the lab findings.
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This is benign intracranial hypertension through an increase in intracranial pressure in the absence of tumor and obstruction to CSF flow. It is caused by decreased CSF resorption. It is associated with normal CT and MRI, increased CSF pressure, and decreased CSF protein.
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Who most commonly presents with Pseudotumor cerebri?
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This is commonly found in young obese females.
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In Subfalcine herniation what part of the brain is herniating under what structure? Which artery is at risk of being compressed?
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In Subfalcine herniation the Cingulate Gyrus herniates under the Falx cerebri. In this type of herniation the is risk of compressing of the Anterior Cerebral Artery (ACA)
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With an Uncal herniation what part of the brain is herniating though what structure? What three structures are being compressed?
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In an Uncal herniation the Medial Part of the temporal lobe herniates through the tentorium cerebelli. The Midbrain, Oculomotor nerve (CN III), and Posterior Cerebral Artery are all compressed in this sort of herniation.
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Compression of which structure during Uncal herniation produces Duret's Hemorrhages?
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Compression of the Midbrain.
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Compression of which structure during Uncal herniation produces "down and out" eye deviation and a Mydraisis (dilated pupil)? Why is does the pupil dilate?
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Compression of the Oculomotor nerve (CN III) produces the "down and out" effect and dilation of the pupil. The dilation of the pupil occurs because the parasympathetic postganglionic fibers run in CN III.
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Compression of which structure during Uncal herniation produces hemorrhagic infarction of the occipital lobe?
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Compression of the Posterior Cerebral Artery.
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What are the consequences of Cerebellar tonsillar herniation? Through which structure do the tonsils herniate?
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Tonsillar herniation occurs into the foramen magnum and produces "coning" of the cerebellar tonsils and cardiorespiratory arrest.
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What is the definition of hydrocephalus? What are the two categories of hydrocephalus?
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An increase in the CSF volume, which causes enlargement of the ventricles. There are communicating and non-communicating types of hydrocephalus.
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What is the most common cause of hydrocephalus in newborn children?
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Blockage of the aqueduct of Sylvius is the most common cause of hydrocephalus in newborns.
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Compare the characteristics of CSF to those of Serum with respect to Protein, Glucose, White blood cells, and Chloride.
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CSF is and ultrafiltrate that normally has lower Protein and Glucose than serum, no Neutrophils, rare Mononuclear cells, and higher Chloride levels than serum.
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How is CSF reabsorped into the circulation?
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It is reabsorped by the arachnoid granulations into the dural venous sinuses.
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Describe some of the causes of Communicating (non-obstructive) Hydrocephalus. What does the non-obstruction refer to?
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The non-obsruction refers to the open communication between ventricles and subarachnoid space. Causes include increased CSF production (e.g. choroid plexus papilloma), and obstruction of reabsorption by the arachnoid granulations (e.g. postmeningitic scarring, tumor).
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What condition are steroids given in order to prevent during an infective meningitis? What could this condition lead to if not treated.
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Steroids are administered in order to prevent postmeningitic scarring. If scarring occurs it could lead to Communicating Hydrocephalus through inhibition of CSF reabsorption by the arachnoid granulations.
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What process is blocked during a Noncommunicating (obstructive) hydrocephalus? Describe some of the causes.
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In a non-communicating hydrocephalus there is obstruction of CSF flow out of the ventricles. Some of the possible causes include stricture of the aqueduct of Sylvius, tumor of the Fourth Ventricle, Scaring at the base of the brain, Colloid cyst in the third ventricle, and developmental disorders.
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What could increased alpha-fetoprotein in maternal serum or amniotic fluid indicate?
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This could indicate a neural tube defect in the fetus.
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How can mother's protect against neural tube defects in their babies?
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Protection against neural tube defects can be achieved through making sure that folate levels are adequate befor pregnancy.
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Ancephaly indicates what state of development of the brain? How is the amniotic fluid affected? What is the characteristic appearance of fetus?
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Ancephaly describes the complete absence of a brain. There is maternal polyhydramnios, and a frog-like appearance of the fetus.
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What defect does Spina Bifida Oculta result from? Describe an external marker that may allude to such a developmental problem.
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Spina Bifida Oculta occurs because of a defect in closure of the Posterior Vertebral Arch. There may be a dimple or a tuft of hair in the skin overlying L5-S1 alluding to this spinal development defect.
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What is a Meningocoele and where along the spine does it most commonly occur?
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A Meningocoele is Spina Bifida with a cystic mass containing meninges. This most commonly occurs in the lumbosacral region.
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What is a Meningomyelocoele and where does it most commonly occur?
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A Meningomyelocoele is Spina Bifida with a cystic mass containing meninges and spinal cord. This most commonly occurs in the lumbosacral region.
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Describe the brain structure in Arnold-Chiari malformation. What type of hydrocephalus does it lend itself to? Describe the formation of the skull. What other conditions are associtated?
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In Arnold-Chiari syndrome there is caudal extension of the medulla and cerebellar vermis through the foramen magnum. Thus, there is a chance for a non-communicating hydrocephalus to develop. Platybasia is commonly found (flattening of the base of the skull) and meningomylocoele and syringomyelia are also common.
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Dandy-Walker malformation includes what malformed structures of the brain? Which ventricle is dilated? What type of hydrocephalus is this?
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Dandy-Walker malformation involves hypoplasia of the cerebellar vermis. There is Cystic dilation of the fourth ventricle and noncommunicating hydrocephalus.
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Describe Syryngomyelia. What type of malformation is it and what developmental malformation of the lower brain is it associated with?
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Syringomyelia is a degenerative disease of the spinal cord due to a fluid-filled cavity (syrinx) within the cervical spinal. This produces cervical cord enlargement and the cavity expands and causes degeneration of spinal tracts. It is also associated with Arnold-Chiari malformation.
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Describe the clinical findings associated with Syringomelyia. Which neurological tracts are disrupted?
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Syringomyelia is characterized by disruption of the crossed lateral spinothalamic tracts, which leads to the loss of pain and temperature sensation in the hands (e.g. the patient can burn hands without being aware of the burn).
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What other neurological disease does Syringomyelia look like? Which characteristics does it share and which separate Synringomelyia from that disease?
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Syringomyelia involves the disruption of the Crossed Lateral Spinothalamic tracts as well as the destruction of the Anterior Horn cells. Thus there can be atrophy of the intrinsic muscles of the hand, which may be easily confused with ALS (amyotrophic lateral sclerosis). The difference between Syringomylia and ALS is that there are no sensory changes associated with ALS, whereas there is decreased pain and temperature sensation in the hands of someone with Syringomyelia.
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Neurocutaneous disorders (Phakomatoses) are the result of disordered growth of what embryonic tissue? What are the two most prominent forms of these diseases?
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Neurocutaneous disorders are the result of disordered growth of Ectodermal tissue, which lead to malformations or tumors of the central nervous system. Tuberous sclerosis and Neurofibromatosis are both examples.
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Describe the main clinical symptoms and associations involved with Tuberous sclerosis. How is this disease inherited?
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Tuberous sclerosis is an autosomal dominant disorder associated with mental retardation and seizures beginning in infancy. Angiofibromas appear on the face along with hypopigmented skin lesions ("ash leaf" lesions, best identified with Wood's lamp). Hamartomatous lesions and Rhabdomyoma in the heart are also key features.
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What are the key features of Tuberous sclerosis? What are examples of these lesions?
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Tuberous Sclerosis is defined by mental retardation and hamartomas in the brain and kidneys. These hamartomatous lesions in the CNS are due to Astrocyte proliferations in the subependyma and look like "candlestick drippings" in the ventricles. In the kidneys, these lesions are Angiomyolipomas.
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What are the key features of Neurofibromatosis?
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Neurofibromatosis is associated with pheochromocytoma, acoustic neuromas and Cafe-au-lait macules.
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How is Neurofibromatosis inherited and what are the clinical signs and symptoms associated?
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Neurofibromatosis is an Autosomal Dominant disorder. It is characterized by Cafe-au-lait macules (pigemented neurofibromas), Lisch nodules (hamartomas in the iris), Kyphoscoliosis, Opitc nerve glioma, meningioma, acoustic neuroma, Pheochromocytoma and Wilm's tumor (both associated with hypertension), and Neurofibrosarcoma (usually involving large nerve trunks).
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What are the main structures affected in Sturge-Weber syndrome? What is the mode of inheritance?
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The mode of inheritance of Sturg-Weber syndrome is somatic mosaicism or sporadic. It invovles Vascular Malformation of the Face and Ipsilateral Arteriovenous Malformation of the Meninges
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What are Coup injuries? What are Countrecoup injuries?
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Coup injuries are the result of head trauma and occur at the site of impact.
Contrecoup injuries occur opposite the site of impact as a result of head trauma. |
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What are common sites for Countrecoup injuries?
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Common sites are at the tips of the frontal and temporal lobes.
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What is the most common cause of cerebral contusion?
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Cerebral contusion is most often secondary to an acceleration-deceleration injury.
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What space in the skull does an Acute Epidural Hematoma occupy? What is the cause of this lesion? How does this lesion cause death?
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An Acute Epidural Hematoma is an arterial bleed that creates a blood-filled space between the bone and dura. It is caused by a fracture of the temporoparietal bone and severance of the middle meningeal artery. Intracranial pressure increases, leading to herniation and death.
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Between what two tissues does the middle meningeal artery lie?
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The Middle Meningeal Artery lies between the dura and the inner table of bone.
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A temporoparietal skull fracture and tear of the middle meningeal artery describe what type of hematoma?
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An Epidural Hematoma.
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Describe the causes of a Subdural Hematoma. What type of blood vessels are involved? Which types of injuries cause this lesion? Explain the clinical findings.
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A Subdural Hematoma is due to a Venous bleed between the dura and arachnoid membranes. This is due to tearing of the bridging veins between the brain and the dural sinuses most often as the result of blunt trauma (e.g. car accident, baseball bat). Patients will experience fluctuating levels of conciousness as blood clots in a sheet between the dura and arachnoid membranes. Herniation and death may occur.
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Describe some of the more common causes of Global Hypoxic injury to the brain.
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Ischemia secondary to atherosclerosis of the carotid artery, chronic carbon monoxide poisoning, chronic hypoxemia (e.g. chronic lung disease).
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Repeat episodes of what type of state has similar effects on the brain as hypoxic injury? Which chronic disease most commonly produces this state?
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Repeated episodes of hypoglycemia have the same effects on the brain as does hypoxic injury. Hypoglycemia most commonly occurs in Type 1 Diabetes Mellitus.
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What are some of the complications of Global Hypoxic Injury?
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Cerebral atrophy, Watershed infarcts, and Cerbrovascular accidents (e.g. strokes).
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Cerebral atrophy occurs due to what type of cell death as a result of hypoxic injury? Which cell type is the most susceptible to hypoxic injury?
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Cerebral atrophy occurs due to apoptosis of neurons in layers 3,5, and 6 of the cerebral cortex and this produces laminar necrosis. Neurons are the most susceptible cell to hypoxic injury.
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What type of Cerebrovascular Accidents are there?
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1. Atherosclerotic stroke
2. Embolic stroke 3. Intracerebral hemorrhage 4. Subarachnoid hemorrhage 5. Lacunar infarcts |
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What type of strokes are there?
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Atherosclerotic stroke, Embolic stroke, and Hemorrhagic stroke.
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What is the most common type of stroke? Which artery is usually involved? Is there hemorrhage associated; why or why not?
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The most common type of stroke is an Atherosclerotic stroke. Pale infarcts occur which indicate liquefactive necrosis. A platelet thrombus develops over a disrupted plaque and the affected vessel is usually the Middle Cerebral Artery or the Internal Carotid Artery near the bifurcation (but most occur in the distribution of the MCA. Hemorrhage only occurs if there is reperfusion, which is usually not the case.
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What type of infarction is associated with Atherosclerotic stroke? Where does the infarction take place in the brain?
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Most Atherosclerotic strokes occur in the distribution of the MCA and result in pale infarction (liquefactive necrosis) and extend to the periphery of the cerebral cortex.
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Describe the gross and microscopic findings associated with Atherosclerotic strokes.
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In an atherosclerotic stroke it would be likely to find a wedge-shaped area of pale infarction that develops at the periphery of the cortex. Swelling of the brain occurs and there is a loss of demarcation between gray and white matter; this is the myelin beginning to break down.
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What is Gliosis and how does it relate an Atherosclerotic type stroke?
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Gliosis is the reaction to cell injury involved in an atherosclerotic stroke. Astrocytes proliferate at the margin's of the infarct and microglial cells (macrophage) remove lipid debris. A cystic area develops in about 10-21 days.
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Describe the clinical signs that precede most strokes. Given these signs, when is a stroke actually called a stroke?
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Most strokes are preceded by transient ischemic attacks, but they are transient neurological deficits that last less than 24 hours. Deficits that do not resolve in 24 hours are called strokes.
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With strokes involving the MCA, what type sensory and motor deficits are oibserved?
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With strokes involving the MCA we see contralateral hemiparesis and sensory loss in the upper extremity. There may be expressive aphasia if Broca's area is involved in the dominant (left) hemisphere and visual defects may occur. The head and neck deviate TOWARD the side of the lesion.
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With strokes involving the Vertebrobasilar Arterial System, what type sensory and motor deficits are oibserved?
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Patients with strokes involving the vertebrobasilar arterial system may present with present with vertigo, ataxia, IPSILATERAL sensory loss in the face, and contralateral hemiparesis and sensory loss in the trunk and limbs.
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If a patient presents with ipsilateral sensory loss in the face and contralateral hemiparesis and sensory loss in the trunk and limbs, what type of cerbrovascular accident might they be experiencing?
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This might be due to a stroke involving the Vertebrobasilar Arterial System.
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What is the most common source of emboli found in Embolic stroke? Why is there more of a risk of hemorrhagic infarction with embolic stroke than with Atherosclerotic stroke? Where do embolic strokes most often occur?
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The most common source of emboli most often originates from the left side of the heart. Embolic stroke can produce hemorrhagic infarction because ischemia due to the emboli can cause tissue damage. Vessel reperfusion after lysis of embolic material produces hemorrhage. Most embolic strokes with hemorrhagic infarction occur in the distribution of the MCA.
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Intracerebral hemorrhage is most often due to what condition? Which specific blood vessels are usually involved? What blood vessel lesion can predispose to intracerebral hemorrhage?
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Intracerebral hemorrhage is most often due to stress imposed on vessels by hypertension. Branches of the Lenticulostriate Vessels develop Charcot-Bouchard macroaneurysms and rupture of these aneurysms produces intracerebral hemorrhage.
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Explain the pathogenesis of Intracerebral hemorrhage and where the most common sites are.
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In an intracerebral hemorrhage the intracerebral hematoma pushes the brain parenchyma aside, causing the pathology. The most common site for intracerebral hemorrhage is the Basal Ganglia, followed by the Thalamus, and Pons and Cerebellar hemispheres.
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Treatment of Hypertension reduces the risk of stroke by what percent?
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Treatment of hypertension reduces the risk of stroke by 40%
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What is the main cause of most Subarachnoid Hemorrhages? What is the second most common cause?
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The majority of Subarachnoid Hemorrhages are secondary to rupture of a congenital berry aneurism. Bleeding from an arteriovenous malformation is a less common cause.
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What is a Congenital Berry Aneurism? How do they develop? What space do ruptures release blood into? What happens to the blood in that space?
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A Congenital Berry Aneurism is an aneurism normally in the Circle of Willis. It may develop from normal hemodynamic stress or hypertension. Most develop at junctions of communicating branches with the main cerebral artery. These junctions lack internal elastic lamina and smooth muscle and are inherently weak. The most common site is at the junction with the ACA.
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What space do ruptured Berry Aneurysms release blood into? What happens to the blood in that space?
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Rupture releases blood into the Subarachnoid space and blood covers the surface of the brain. Blood in the CSF is broken into bilirubin pigment, which imparts a yellow color to the CSF called xanthochromia.
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What are the clinical symptoms associated with a subarachnoid hemorrhage (most often due to a congenital berry aneurysm) and blood in the CSF?
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A sudden onset of severe occipital headache, described as the "worst headache ever". Nuchal rigidity may also be present. About 50% of patients die soon after the hemorrhage.
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What are the two main causes of Lacunar Strokes?
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Lacunar strokes are caused by hyaline arteriolosclerosis secondary either to Hypertension (most common) or Diabetes Mellitus.
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What two special types of stroke syndromes are associated with Lacunar infarcts? Which structures of the brain are involved?
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Pure motor strokes with or without dysarthria can occur if the posterior limb of the internal capsule is involved. Pure sensory strokes can occur if the thalamus is involved.
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What are the various routes of infection of the CNS?
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Hematogenous spread (most common), Traumatic implantation, Local extension from nearby infection, Ascent of a peripheral nerve.
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Most CNS infections are due to what type of spread?
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Hematogenous spread (sepsis).
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Compare and contrast the differences in the Total Cell Count and also in the Differential Cell Count, found in Bacterial/Fungal meningitis vs. Viral meningitis.
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In bacterial/fungal meningitis the Total Cell Count will be 1000-20,000 cells/mm3 vs. viral meningitis where the TCC will be <1000 cells/mm3.
In bacterial/fungal meningitis the Differential Cell Count will show >90% neutrophils and mononuclear cells vs. viral meningitis where in the first 24-48 hours neutrophils are observed, but then the predominate cell switch to lymphocytes/monocytes after 48 hours. |
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What do the CSF glucose and protein levels look like in a patient with Bacterial/Fungal meningitis. What type of Gram stain comes through?
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In a patient with bacterial/fungal meningitis CSF protein is increased, but CSF glucose is decreased. The Gram stain is frequently positive.
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What do the CSF glucose and protein levels look like in a patient with Viral meningitis. What type of Gram stain comes through?
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In a patient with viral meningitis the CSF protein is increased and the CSF glucose is normal- *exceptions include mumps and herpes. Gram stains are negative.
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Meningitis is usually and inflammation of which level of the meninges that covers the brain?
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Meningitis is an inflammation of the Pia Matter that covers the brain.
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What are the main clinical findings associated with Meningitis?
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Fever, nuchal rigidity, and headache.
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Why do we see increased CSF protein in all types of Meningitis?
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We see increased CSF protein in Meningitis due to increased vessel permeability.
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What is the definition of Encephalitis? Describe the key clinical findings.
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Encephalitis is defined as inflammation of the brain. The clinical findings include fever, headache, impaired mental status and DROWSINESS.
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Explain two possible ways that Cerebral abscesses can form.
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Cerebral abscesses can form via spread from an adjacent focus of infection (e.g. sinuses) or Hematogenous spread (e.g. infective endocarditis). There can
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Describe the three main types of Demylinating Disorders. Provide examples of each.
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1. Destruction of normal myelin
-Multiple Sclerosis 2. Production of abnormal myeliin -Leukodystrophy 3. Destruction of oligodendrocytes -Multiple Sclerosis, slow virus infections |
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Which type of inflammation do Arboviruses cause in the CNS? What type of vectors and reservoirs carry these type of viruses? Give an example of this type of virus and where it occurs in the U.S.
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Arboviruses cause Encephalitis. Mosquitoes are the vector for these viruses and the reservoir are wild birds. West Nile virus is an example of this type of virus, which has been found in NY, but crows and other birds are spreading the disease to the West Coast.
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What four viruses cause encephalitis only, and not meningitis?
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Arbovirus, Cytomegalovirus, HIV, and Rabies virus.
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Which two viruses cause encephalitis and meningitis?
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HSV1 and Lymphocytic Choriomeningitis virus.
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Which virus causes only Meningitis and is the main cause of viral meningitis?
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Coxsackievirus.
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Which virus causes Encephalitis and myelitis (spinal cord)?
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Poliovirus.
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When does viral meningitis tend to peak during the course of the year? What is the most common cause of viral meningitis?
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Viral meningitis tends to peak in late summer and early autumn. The most common cause of viral meningitis is Coxsackievirus.
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What virus is the most common cause of viral CNS infection found in AIDS patients? This virus also causes periventricular calcification in newborns.
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This is a description of Cytomegalovirus. Cells are characteristically seen to have primarily intranuclear basophilic inclusions.
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Herpes Simplex Virus Type1 causes encephalitis and meningitis, and what type of lesion to the temporal lobes?
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HSV1 causes hemorrhagic necrosis to the temporal lobes.
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How does HIV affect the brain and neuronal cells? What is the most common cause of AIDS dementia?
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HIV causes encephalitis and causes microglial cells to fuse to form multinucleated cells. The HIV virus is the most common cause of AIDS dementia.
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What type of CNS inflammation does Lymphocytic Choriomeningitis Virus cause? Describe the symptoms. How is this virus transmitted? Describe the CSF protein/glucose/cell profile.
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Lymphocytic Choriomeningitis Virus causes meningitis and encephalitis. Meningoencephalitis is a combination of nuchal rigidity (meningitis) and mental status abnormalities (encephalitis). This virus is endemic in the mouse populations and is transmitted via food or water that is contaminated with mouse urine/feces. CSF findings include increased protein, normal to decreased glucose, and lymphocytic infiltrate.
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Describe the damage that Poliovirus causes to the CNS. What type of CNS inflammation is it associated with?
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Poliovirus destroys both upper and lower motor neurons, thus causing muscle paralysis. It is associated with encephalitis and myelitis of the spinal cord.
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How is the Rabies virus most often transmitted? What are other common vectors? What tissues does the virus infect? Describe the characteristic microscopic picture of the cell. What characteritic symptoms does it produce?
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The Rabies virus is most often transmitted via raccoon bite (40%) of cases. Other vectors include dog, skunk, bat, and coyote. The virus ascends peripheral nerves and the neurons contain intracytoplasmic Negri bodies. The virus produces a characteristic CNS excitability stage followed by flaccid paralysis.
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How is Creutzfeld-Jakob Disease transmitted?
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It is transmitted by corneal transplantation, contact with human brain, use of improperly sterilized cortical electrodes, or ingestion of tissues from cattle with bovine spongiform encephalopathy ("mad cow" disease).
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Describe the appearance of the brain of a patient with Creutzfeld-Jakob Disease. How long is the life expectancy for a patient with this disease?
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The brain has a "bubbles and holes" appearance, which is called a spongiform change in the cerebral cortex. Death usually occurs within 1 year.
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Which virus is responsible for producing Progressive Multifocal Leukoencephalopathy? Which cells contain intranuclear inclusions? What Disease does this occur on the background of?
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Papovavirus causes this conventional slow virus encephalitis. Oligodendrocytes are seen to have intranuclear inclusions. Progressive Multifocal Leukoencephalopathy occurs in AIDS patients when CD4+ count is <50 cells/ul.
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Papovavirus causes what type of encephalopathy in what special condition?
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Papovavirus causes Progressive Multifocal Leukencephalopathy. This usually only occurs in AIDS patients the have a CD4 T helper count <50
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Subacute Sclerosing Panencephalitis is caused by what disease? Where are intranuclear inclusions seen in this type of conventional slow virus encephalitis? What is the time course of the disease?
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Subacute Sclerosing Panencephalitis is associated with Rubeola (measles) virus. In this conventional slow virus encephalitis intranuclear inclusions are seen in both oligodendrocytes AND neurons. Death usually occurs in 1-2 years.
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What are the two most common causes of Neonatal Meningitis in order of most common to least common?
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Group B Streptococcus (Strep agalactiae) > E.coli
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What Gram (+) rod that exhibits tumbling motility and is a pathogen found in soft cheeses and hotdogs can cause neonatal meningitis?
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Listeria monocytogenes.
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Describe the basic cell morphology of Neisseria meningitidis. For what age of the population is it the most common cause of bacterial meningitis?
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Neisseria is a Gram (-) diplococcus and is the most common cause of meningitis between 1 month and 18 years of age.
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Describe the basic morphology of Streptococcus pneumoniae. For what age of the population is it the most common cause of bacterial meningitis?
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Strep pneumo is a Gram (+) diplococcus and is the most common cause of meningitis for patients >18 years of age.
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Meningitis can be a complication of Primary Tuberculosis with an infection of the organism Mycobacterium tuberculosis. What part of the brain is most affected? What lesion can occur in the vasculature of the CNS? Name another condition this can lead to.
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TB meningitis normally affects the base of the brain. It can cause vasculitis in the blood vessels that supply the CNS, leading to infarction, and can also cause hydrocephalus.
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Which types of CNS inflammation does Treponema pallidum cause? What other form of nervous injury does it cause?
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Syphilis causes meningitis and encephalitis, as well as myelitis.
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Describe the three main types of neurosyphilis. What symptoms does each involve?
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Meningovascular: vasculitis causing strokes
General paresis: dementia Tabes dorsalis: involves the posterior root ganglia and posterior column; causes ataxia, loss of vibration sensation, absent deep tendon reflexes, Argyll-Robertson pupil (pupils accommodate but do not react). |
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What is the most common fungal CNS infection seen in AIDS patients? Describe the morphology of the cells of this organism. What type of CNS inflammation does it cause?
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The most common fungal CNS infection is Cryptococcus neoformans. Budding yeasts are visible with India ink and the very characteristic CAPSULE is easily observed. Cryptococcus neoformans causes Meningitis and Encephalitis.
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Mucor species of fungus tend to infect what very specific patient population? What is the route of infection to the CNS and what type of lesion does it cause?
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Mucor species tend to infect Diabetic patients in ketoacidosis. Infection usually takes hold in the frontal sinuses and spreads to the CNS leading to Frontal Lobe abscess.
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Naegleria fowleri is a fungus that is contracted by what participating in what activity? Which lobes of the brain are usually involved and what type of CNS inflammation does it cause?
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Naegleria fowleri is contracted by swimming in freshwater lakes. Infection primarily affects the Frontal Lobes and causes meningoencephalitis.
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What is Taenia solium? What disease does it cause? Describe the signs and symptoms associated with this disease.
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Taenia solium is a tapeworm. If the larvae of Taenia solium migrate to the brain they can cause a disease called Cysticerrcosis. In Cysticercosis, the patient (intermediate host) ingests food or water containing eggs; the eggs develop into larval forms (cysticerci) that can invade the brain, producing calcified cysts causing seizures.
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What is the most common space occupying lesion in the CNS found in patient with AIDS? How does the congenital form of this disease affect the CNS?
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Toxoplasma gondii (causing toxoplasmosis) causes an encephalitis in AIDS patients and is the most common CNS space-occupying lesion in AIDS patients. Congenital toxoplasmosis produces basal ganglia calcification.
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What is the most common acquired demyelinating disorder? Does this disease have a predominance for a particular sex? What is the genetic mutation thought to be associated with this disease?
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Multiple sclerosis is the most common acquire demyelinating disorder. It has a female predominance (20-40 year of age), and is associated with HLA-DR2.
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Describe the pathogenesis of Multiple sclerosis. What causes the destruction of myelin sheaths? Describe the gross findings.
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MS is an autoimmune destruction of the myelin sheath and oligodendrocytes that is mediated by CD8 T-cells. Antibodies directed against myelin basic protein in oligodendrocytes may also be present. Gross findings reveal demyelinating plaques that occur in white matter of the brain and spinal cord.
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Describe the clinical findings associated with Multiple Sclerosis. How are motor and sensory functions affected?
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Symptoms of Multiple Sclerosis occur in an episodic course punctuated by acute relapses and remissions. Patients experience paresthesias and muscle weakness. Optic neuritis (blurry vision or sudden loss of vision) is common due to inflammation of the optic nerve. Cerebellar ataxia, scanning speech (drunk sounding), intention tremor, and nystagmus are all characteristic as well.
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What lesion is pathognomonic for MS?
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Bilateral internuclear opthalmopelgia due to demyelination of the Medial Longitudinal Fasciculus (MLF)- loss on conjugated eye movement.
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Describe the laboratory findings associated with Multiple Sclerosis. Which fluid is are the tests performed with?
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CSF is the main body fluid used to test in MS. Leukocyte count, protein levels and glucose levels are all evaluated. There is an increased leukocyte count (primarily T lymphocytes), increased protein (primarily increased gamma globulins), increased myelin basic protein (indicates active disease), and normal CSF glucose.
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What other test besides testing CSF for leukocyte, protein, and glucose levels are used to confirm a diagnosis of Multiple Sclerosis?
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High resolution electrophoresis shows oligoclonal bands. These are discrete bands of protein in the gamma-globulin region and are a sign of demyelination.
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What type of acquired demyelinating disorder is due to medical intervention? Who are the patients that this happens most often to and what is the cause?
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Central Pontine Myelinosis is due to rapid intravenous correction of hyponatremia. Here there is demyelination at the basis of the pontis. This most often occurs in alcoholics who have hyponatremia
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Viral infections that result in direct infection of oligodendrocytes have been seen to produce what two diseases? What are the viruses associated with each disease?
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Examples are Progressive Multifocal Leukencephalopathy (Papovavirus), and Subacute Sclerosing Panencephalitis (Rubeola)
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Describe what class of metabolic diseases are leukodystophies are? List three examples that affect the CNS and are demyelinating disorders.
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Leukodystrophies are inborn errors of metabolism. Examples include Adrenoleukodystrophy, Metachromatic leukodystrophy, and Krabbe's disease.
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What X-linked recessive disorder is due to an enzyme deficiency in B-oxidation of fatty acids in peroxisomes? Describe the resulting pathophysiology of this disease.
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This describes Adrenoleukodystrophy. The enzyme deficiency in B-oxidation of fatty acids in peroxisomes results in accumulation of long-chain fatty acids. This causes generalized loss of myelin in the brain and adrenal insufficiency.
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Which leukodystrophy results from a deficiency of Arylsulfatase A? What class of disease is this? How is this diisease inherited?
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Metachromatic leukodystrophy is a lysosmal storage disease that is due to a deficiency in Arylsulfatase A. This disease results in accumulation of sulfatides. It is inherited in an autosomal recessive fashion.
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What disease is caused as a result of B-galactocerebrosidase deficiency? What molecule is accumulated? Describe what the microscopic picture of the brain looks like.
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Krabbe's disease is an autosomal recessive lysosomal storage disease. The lack of B--galactocerebrosidase leads to accumulation of galactocerebroside. Under the microscope, the brain shows large, multinucleated, histiocytic cells (globoid cells).
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What are the six major Neurodegenerative disorders that you need to know?
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1) Alzheimer's disease
2) Parkinsonism 3) Huntington's disease 4) Fredrich's ataxia 5) Lou Gerhig's disease (ALS) 6) Werdnig-Hoffman disease |
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What is the most common cause of dementia?
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Alzheimer's diseasegalkdsflaskdhflaksdflak
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Describe the role of B-amyloid protein in Alzheimer's disease. Why do most Downsyndrome patient's develop Alzheimer's by age 40? Defects in degradation of what protein by what enzyme, leads to the development of B-amyloid protein?
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B-amyloid protein (deposits in neurons and is neurotoxic) is formed from APP (amyloid precursor protein) when defects in degradation of APP by secretases occur. APP is normally coded on Chromosome 21, thus Down syndrome patients have a greater increase in APP and are more likely to develop Alzheimer's disease.
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What are the secretases that normally do the job of breaking down APP (associated with Alzheimer's disease) into safe peptides, and what are those that allow formation of B-amyloid protein?
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Alpha-secretases cleave APP into fragments that cannot produce B-amyloid protein, while Beta- and Gamma- secretases cleave APP into fragments that ARE converted into B-amyloid protein.
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Describe the Apolipoprotein mutation on Chromosome 19 that contributes to familial late-onset Alzheimer's disease. Which gene is it and what is its pathogenesis?
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Apolipoprotein gene E, allele 4, located on chromosome 19 causes a familial late-onset Alzheimer's disease. The gene codes for a product with a high binding affinity for B-amyloid protein.
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Explain the role of Tau protein as it relates to Alzheimer's disease. What is the normal function of this protein? Which chromosome mutation is it associated with and what type of protein does this result in? What sort of aggregate does it create?
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The normal function of Tau protein is to maintain microtubules in neurons. Mutations in Chromosome 14 produce a hyperphosphorylated Tau protein and this protein is responsible for causing the formation of neurofibrillary (NF) tangles associated with Alzheimer's disease.
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Describe the gross and microscopic findings associated with Alzheimer's disease. What is hydrocephalus ex vacuo? Which lobe is usually spared? What features are also seen in other diseases?
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In Alzheimer's patients we see cerebral atrophy with apparent dilation of ventricles (hydrocephalus ex vacuo). This atrophy is due to a loss of neurons in the temporal, frontal, and parietal lobes. The occipital lobe is usually spared. Amyloid plaques and NF tangles are seen, although NF tangles can also be observed in other disease processes, such as Huntigton's disease.
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What is amyloid angiopathy and which neurodegenerative disease is it associated with? What does it put a patient at risk for?
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Amyloid angiopathy is associated with Alzheimer's disease.B-amyloid deposits in the walls of cerebral blood vessels and causes a weakening of the vessels. This puts the patient at an increased risk of hemorrhage.
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What is the only way to obtain definitive confirmation of alzheimer's disease?
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This requires a postmortum examination of the brain and there must be widespread presence of NF tangle and senile plaques.
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What are the clinical findings in a patient with Alzheimer's? Are there neurological deficits present? What is usually the cause of death in these patients?
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In Alzheimer's patients there is a general impairment of higher intellectual function, but there are NO neurological deficits present. Patients usually die from infection (related to immobility), an example of which is intercurrent bronchopneumonia.
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In Parkinsonism, loss of which main structure is responsible for the symptoms we see? What is the nuerotransmitter deficit that is invovled?
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Parkinson ism is a group of disorders that alter dopaminergic pathways involved in voluntary muscle movement.
Parkinsonism is due to a loss of the Substantia Nigra, in which depigmentation is observed and a loss of Dopamine is detected. |
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Name the structures of the Striatal system that are involved in voluntary movement.
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Substantia nigra, caudate, putamen, globus palliidus, subthalamus, thalamus.
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Dopamine is the principle neurotransmitter in what tract that allows voluntary movement? Which structures are involved in this tract?
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Dopamine is the principle neurotransmitter in the nigrostriatal tract. It connects the substantia nigra with the caudate and putamen.
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What is the most common age range of Idiopathic Parkinson's disease? What characteristic intracellular inclusions are seen? Describe the clinical symptoms that are observed.
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45-60 years old. Neurons of the Substantia nigra contain intracytoplasmic, eosinophilic bodies called Lewy bodies, which are ubiquinated damaged neurofilaments. Clinical findings include muscle rigidity and the slowness of voluntary movement (bradykinesia), resting tremor, illegible writing, expressionless face, stooped posture, shuffling gait, and dementia in some cases.
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What are some of the non-idiopathic causes of parkinsonism?
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Encephalitis, ischemia, chronic carbon monoxide poisoning (causes necrosis of globus pallidus), Wilson's disease, MPTP, and antipsychotic drugs (e.g. phenothiazines)
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What cerebral structure is lost in Huntington's disease? What is the genetic cause of the destruction of these neurons and how is this disease inherited? At what age does this present and with what symptoms?
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In Huntington's disease there is atrophy/loss of striatal neurons: 1) Caudate, 2) Putamen, 3) Globus Pallidus. Huntington's is an Autosomal Dominant disease due and a Trinucleotide repeat disorder involving Chromosome 4. There is a delayed appearance os symptoms until 35 to 40 years of age, when chorea, muscle rigidity, and dementia begin to appear.
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What is the cerebral structure lost in Huntington's disease?
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In Huntington's disease there is atrophy of the caudate.
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What is Fredrich's ataxia? How is this disease inherited? Describe the underlying genetic cause. What are the nervous system structures involved and what are the symptoms that are produced?
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Fredrich's ataxia is an autosomal recessive disease that occur due to Trinucleotide repeats. The structures involved include the Cerebellum (ataxic gait), Posterior and Lateral columns of the spinal cord (diminished joint sensation, spasticity, respectively), Peripheral neuropathy, and Hypertrophic cardiomyopathy.
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ALS involves degeneration of what type of neurons? When do symptoms appear? Describe the clinical findings.
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ALS involves the degeneration of both upper and lower motor neurons. Symptoms usually appear around 40-60 years of age. Upper motor neuron signs consist of Spasticity and Babinski's sign. Lower motor neuron signs include muscle weakness (**begins with atrophy of intrinsic muscles of the hand**), and eventually paralysis of the respiratory muscles leading to death. Average survival time is 3 to 5 years.
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What is Werdnig-Hoffman disease and what patient population does it occur most often in?
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Werndig-Hoffman disease is a lower motor neuron disease that occurs in children.
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Describe the etiology of Wilson's disease and how it affects the CNS. What do the signs and symptoms look like? Which cerebral structures are affected?
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Wilson's disease is an autosomal recessive disease due to a defect of copper excretion in bile, which occurs because of a defect in ceruloplasmin. This leads to liver cirrhosis and excess free copper in the blood. CNS findings include signs of parkinsonism, chorea, and dementia due to atrophy and cavitation of the basal ganglia, particularly the putamen.
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The excess free copper in Wilson's disease leads to cystic degeneration of what brain structure?
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The Putamen.
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Which chromosome are the familial cases of ALS associated with? What is the gene defect and how does this lead to neuronal injury?
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The gene defect associated with familial ALS is a defect of Superoxide dismutase 1, on Chromosome 21. This allows the production of superoxide free radicals to go unchecked and permits the destruction of neurons.
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Describe the enzyme deficiency associated with Acute Intermittent Porphyria (AIP). Describe the pathogenesis. What clinical findings are the attacks associated with? What conditions are thought to exacerbate/induce the attacks?
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AIP is an autosomal dominant disorder associated with a defect in Porphyrin metabolism due to a deficiency of Porphobilinogen Deaminase. There is a proximal increase in Porphobilinogen (PBG) and delta-Aminolevulenic acid (ALA). Clinical findings include neurologic dysfunction with recurrent bouts of severe abdominal pain simulating acute abdomen ("belly full of scars"), psychosis, peripheralneruopathy, and dementia. Drugs that enhance the P-450 system exacerbate this condition (e.g. alcohol).
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What are the physical effects that Vitamin B12 deficiency has on the CNS? Describe the clinical symptoms.
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Vitamin B12 deficiency is associated with subacute combined degeneration of the spinal cord involving Posterior Column and Lateral Cotricospinal Tract demyelination. Dementia and peripheral neuropathy are the main clincal symptoms.
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What are the main CNS disorders associated with alcohol abuse?
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1) Cortical and cerebellar atrophy
2) Central pontine myelinosis 3) Wernike-Korsakoff syndrome |
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Wernike-Korsakoff syndrome associated with alcohol abuse is most often due to a deficiency of what vitamin? What are the gross and microscopic findings that are associated?
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Wernike-Korsakoff syndrome is most often due to a Thiamine deficiency. Grossly, hemorrhages with hemosiderin deposits may occur in the mammillary bodies of the third and fourth venttricles. Microscopically, neuronal loss gliosis, and vessel hemorrhage are visible.
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Describe the reversible findings of Wernike's encephalopathy, which is a part of Wernike-Korsakoff syndrome.
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Reversible symptoms of Wernike's encephalopathy include confusion, ataxia, nystagmus, opthalmopelgia (eye muscle weakness).
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Define Korsakoff's psychosis as it relates to being a part of Wernike-Korsakoff syndrome. What type of mental deficits does it involve? Is this reversible?
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Korsakoff's psychosis is an advanced irreversible stage of Wernike's encephalopathy, which targets the limbic system. There is Anterograde amnesia (inability to form new memories), and Retrograde amnesia (inability to recall old memories).
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What is the most common primary brain tumor found in adults? Which are the next two most common?
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Glioblastoma multiforme. Then Meningioma and Ependyoma.
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In what way is the Tentorium Cerebelli a marker for a the difference of where most tumor happen in adults vs. children?
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Approx 70% of tumors in adults occur above the Tentorium Cerebelli, and approx 70% of tumors in children occur below the Tentorium Cerebelli.
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Describe the most common primary brain tumors found in children in order of decreasing frequency.
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Cystic cerebellar astrocytoma > Medulloblastoma > Brainstem glioma
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What are three major risk factors for brain tumors?
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Turcot's syndrome, Neurofibromatosis, cigarette smoking.
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In which CNS structure do the two most common childhood tumors (Cystic astrocytoma and Medullloblasotma) occur?
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Both of these tumors occur in the cerebellum.
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What is the most common neuroglial tumor? What are the different locations that this tumor occurs depending on whether it is found in adults or children?
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Astrocytomas account for about 70% of all neuroglial tumors and are therefor the most common type. These tumors usually occur in the frontal lobes in adults, and involve the cerebellum in children.
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What type of tumor is a Glioblastoma multiforme? Is this a high-grade or low-grade tumor? How does it arise? Does this tumor hemorrhage or metasticize?
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Glioblastoma multiforme is a high-grade astrocytoma. This tumor may arise de novo, or it may arise from dedifferentiation of a low-grade astrocytoma. It is a hemorrhagic tumor with multifocal areas of necrosis and cystic degeneration, and it commonly crosses the corpus callosum. It may seed the neuraxis via CSF and rarely metastasizes outside the CNS.
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What is the most common benign brain tumor in adults? Which sex has the higher predominance and why? What cells are these tumors derived from? Where do they occur most commonly?
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Meningiomas are the most common benign brain tumor in adults. They have a female predominance and this is thought to be so due to the estrogen receptors found in the tumors. The tumors are derived from arachnoidal cells from the parasagittal location, olfactory groove, and lesser wing of the sphenoid.
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What disease in particular is associated with the development of Meningiomas?
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Neurofibromatosis.
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An Ependyoma is a benign tumor derived from what cells? How does its location in the brain differ when it arises in an adult versus a child?
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Ependyomas are derived from ependymal cells. In adults, ependyomas arise in the cauda equina. In children, ependyomas arise in the 4th ventricle.
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What type of tumor is a Medulloblastoma and what population does it occur most in? Which cells does it arise from? What structures does it affect?
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A Medulloblastoma is a malignant small cell tumor that occurs primarily in children. It arises from the external granular cell layer of the cerebellum and often seeds the neuraxis and invades the fourth ventricle.
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Describe the gross and microscopic findings of Meningiomas.
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Grossly, Meningioma's are firm tumors that may indent, but not invade, the surface of the brain. They often infiltrate overlying bone and can cause increased bone density. Microscopically, swirling masses of meningothelial cells encompass psammoma bodies (calcified bodies) are observed.
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Which benign brain tumor has a female predominance, shows psammomma bodies, is a common cause of new-onset focal seizures, and is associated with Neurofibromatosis?
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A Meningioma.
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What is the most common cause of peripheral neuropathy? Describe the pathophysiology of this disease and how it causes peripheral neuropathy.
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The most common cause of peripheral neuropathy is Diabetes mellitus. It does this by causing osmotic damage to Schwann cells.
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What are some examples of Toxin-associated peripheral neuropathies?
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Alcohol, heavy metals, diptheria toxin.
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Which nerve is affected in Idiopathic Bell's Palsy? What is the process occurring?
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Idiopathic Bell's Palsy involves lower motor neuron palsy causing unilateral facial paralysis. This is usually due to an inflammatory reaction of the Facial Nerve (CN VII) and occurs at a location near the stylomastoid foramen or in the bony facial canal.
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What diseases can be associated with Bell's Palsy? Describe the symptoms.
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Bell's palsy may be associated with HIV, sarcoidosis, and Lyme disease. It is often bilateral in Lyme disease. Clinical findings include drooping of the corner of the mouth, difficulty speaking, and an inability to close the eye.
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What are two common examples of drugs that can produce peripheral neuropathy?
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Vincristine and Hydralazine.
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What are examples of vitamin deficiencies that produce peripheral neuropathies?
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Deficiency of Thiamine, Vitamin B12, and Pyroxidine.
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What type of conjunctivitis is viral conjunctivitis? Which viruses are known to cause conjunctivitis?
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Viral conjunctivitis produces watery exudates. Adenovirus (viral cause of pink eye and periauricular lymphadenopathy), and HSV-1 (keratoconjunctivitis with dendritic ulcers noted on flourescent stain) are the most common causes of viral conjunctivitis.
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What organism is most commonly responsible for severe conjunctivitis in patients who do not clean their contact lenses properly?
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Acanthamoeba conjunctivitis.
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What is a stye and what organism is responsible for causing this lesion?
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A stye is an infection of the upper eye lid and is most commonly due to Staph aureus.
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What is a Chalazion?
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A Chalazion is a granulomatous inflammation involving the meibomian gland in the eyelid.
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Orbital cellulitis is most commonly caused by which bacterial pathogens? Describe some of the symptoms that accompany Orbital cellulitis.
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Orbital cellulitis is most often due to an infection with S.pneumoniae or H.influenzae. Symptoms include periorbital redness and swelling that is often secondary to sinusitis (e.g. ethmoiditis in children), fever proptosis (eye buldging), opthalmopelgia (eye movement impaired), normal retinal examination.
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What is Pterygium? What is it caused by?
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This is raised, triangular encroachment of thickened conjuctiva on the nasal side of the conjunctiva. This is most often caused due to excessive exposure to wind, sun, and sand.
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What is Optic Neuritis and what are its causes? Describe the symptoms associated with Optic Neuritis.
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Optic neuritis is inflammation of the optic nerve. The causes usually include Multiple Sclerosis (most common), and methanol poisoning. Symptoms of Optic neruitis are characterized by blurry vision or loss of vision, and optic atrophy.
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What are the most common causes of Central Retinal Artery Occlusion? Describe the signs and symptoms associated that will indicate this condition.
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Common causes include embolization of plaque material from the ipsilateral carotid or opthalmic artery and Giant Cell Arteritis involving the opthalmic artery. Signs and symptoms of this condition involve sudden painless complete loss of vision in one eye, pallor of the optic disk, and "boxcar segmentation of the of blood in the retinal veins.
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What are the most common causes of Central Retinal Vein Occlusion? Describe the signs and symptoms associated that will indicate this condition.
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Thye most common cause is due to a hypercoagulable states (e.g. polycythemia vera). Signs and symptoms include sudden painless unilateral loss of vision, swelling of the optic disk, and engorged retinal veins with hemorrhage.
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Describe the pathophysiology of Glaucoma. What are the two main types?
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Glaucoma is defined as increased ocular pressure. There are two main types: 1) Chronic open angle Glaucoma 2) Acute angle-closure Glaucoma
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What is the main pathology in Chronic Open Angle Galucoma? Describe the signs and symptoms that are associated with this type of Glaucoma and what the eventual sensory loss is.
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Chronic Open Angle Glaucoma is due to a decreased rate of aqueous outflow into the canal of Schlemm. Signs and symptoms include aching eyes, pathological cupping of the optic disks, night blindness and gradual loss of peripheral vision leading to tunnel vision and blindness.
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What is the main pathology in Acute Angle-closure Galucoma? What exacerbates this condition? Describe the signs and symptoms that are associated with this type of Glaucoma and what the eventual sensory loss is.
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Acute Angle-closure Glaucoma is due to narrowing of the anterior chamber angle. This can be precipitated or exacerbated by mydriatic agents, uveitis, or lens dislocation. There is severe pain is associated with photophobia and blurry vision. There may also be a red eye with a steamy cornea and a pupil that is fixed and non-reactive to light.
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Optic nerve atrophy leads to what physical findings? What is the most common cause of Optic nerve atrophy?
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Optic nerve atrophy produces a pale optic disk and is most commonly due to optic neuritis or glaucoma.
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What is Uveitis? Describe the most common causes. What type of symptoms are associated with Uveitis?
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Uveitis is inflammation of the uveal tract (iris, ciliary body,choroid). Uveitis is most commonly associated with diseases such as Sarcoidosis, Ulcerative colitis, and Ankylosing Spondylitis. Symptoms include Pain with blurry vision, mitotic pupil, circumcorneal ciliary body vascular congestion, normal intraocular pressure, and adhesions between the iris and anterior lens capsule.
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What is the most common cause of permanent visual loss in the elderly? Disruption of which membrane causes this pathology? What can decrease the risk of developing this disease?
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Macular degeneration is the most common cause of permanent visual loss in the elderly. Disruption of Bruch's membrane in the retina is the main cause behind this pathology. Antioxidants decrease the risk of development of this disease.
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Which virus is responsible for being the most common cause of blindness associated with AIDS? At what level of CD4 count does this occur? What type of symptoms are seen? Which medications are prescribed to treat it?
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CMV retinitis is the most common cause of blindness related to AIDS. This usually occurs when CD4 T helper count <50 cell/ul. Cotton wool exudates and retinal hemorrhages are seen, and this condition is treated with Gancyclovir and Foscarnet.
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Describe what Cataracts is and what causes it. What type of infections is this disease common in?
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Cataracts is opacity in the lens of the eye. The most common cause is advancing age, but diabetes mellitus (osmotic damage), infection (e.g. rubella), and corticosteroids are also causes. This disease is common in congenital infections (e.g. CMV & rubella) |
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What eye tumors are common in children and adults?
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Children: Retinoblastoma ("white eye reflex")
Adults: Malignant Melanoma |
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Mass CNS lesion or multifocal CNS lesions found in a patient with AIDS makes you think of what two diseases?
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Mass lesion: Toxoplasmosis
Multifocal lesions: Progressive Multifocal Leukencephalopathy caused by Papovavirus |
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Does variant CJD occur in older or younger patients?
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This occurs in younger patients.
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Wernike disease results from a deficiency in what vitamin? Describe the eye symptoms associated with this disease and why they occur?
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Wernike disease results from a deficiency of Thiamine. Capillary proliferation, hemorrhage, necrosis, and hemosiderin deposition are often found in the mammilary bodies and the periaqueductal gray matter, resulting in paralysis of the extraocular muscles.
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Niacin deficiency is associated with what type of CNS problems?
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Niacin deficiency is associated with dementia.
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Deficiency of Pyridoxine may result in what type of peripheral nerve symptoms?
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Deficiency in Pyridoxine may result in peripheral neuropathy.
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Subacute combined degeneration of the spinal cord is associated with what vitamin deficiency?
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Colbalamin (Vitamin B12) deficiency.
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What is the most typical manifestation of CNS Cryptococcus infection in an AIDS patient? How did this infection probably start? How can this fungus be visualized?
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Meningitis. This infection probably began via the lungs. This fungus is visualized and identified via the india ink test and elucidation of its capsule.
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What type of lesion does Toxoplasma most commonly causes in the CNS of AIDS patients?
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It most commonly causes parenchymal brain abscess.
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At what particular location are metastases usually found in the brain? Describe the metastases found from a melanoma.
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Metastases are typically multiple and are found at the gray-white junction, where peripheral arteries branch and narrow acutely. Metastases from malignant melanomas are often widely disseminated, with multiple mass lesions in organ sites of involvement.
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Are the neurofibromas and schwannomas of Neurofibromatosis Type 1 peripheral or cortical?
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They are peripheral.
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Hemorrhagic lesions of the temporal lobes are characteristic of what viral infection?
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These are characteristic of Herpes Simplex Virus infection.
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When you hear of an alcoholic patient with increasingly altered mental status and flapping tremor of the outstretched hand what should you think of? Describe the etiology and other symptoms of this condition.
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The build up of Nitrogen in the blood; Hyperammonemia. This is asterixis and is a condition that can occur in severe liver disease of any type. Hyperammonemia is a feature of liver failure.
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What genetic mutation is associated with increased risk of developing Alzheimer's disease?
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The presence of the Epsillon 4 allele of the ApoE4 gene is associated with an increased risk of developing Alzheimer's.
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What is the trinucleotide expansion repeat at which gene locus that is associated with the inheritance of Huntington's disease?
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Expansion of CAG repeats on Chromosome 4p16 causes Huntington's disease.
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Which veins are at risk of "tearing" with head trauma in OLDER populations and why? What type of hemorrhage do they cause?
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Bridging veins are at risk for tear with head trauma in older populations because natural cerebral atrophy leaves them "dangling in the wind" as the brain matter pulls away from the arachnoid matter. Tearing of bridging veins causes subdural hemorrhages.
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What type of hemorrhages are pontine hemorrhages most likely to be?
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Pontine hemorrhages are most likely to be Duret hemorrhages.
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What is another name for a basal ganglia hemorrhage and what condition are they most always associated with?
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Another name for hemorrhage in the basal ganglia is Intracerebral hemorrhage. This type of hemorrhage is almost always associated with hypertension.
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A tear to the middle meningeal artery leads to what type of hemorrhage? What characteristic sign occurs with this type of hemorrage?
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Epidural hemorrhages are due to a tear of the middle meningeal artery. There is commonly a "lucid" interval between initial loss of conciousness occuring with trauma and the later accumulation of blood.
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Acute Lymphocytic Meningitis is caused by what types of virus? List some examples. Is this type of meningitis most often fatal?
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Acute Lymphocytic Meningitis is caused by Arbovirus. Some examples of viruses that cause this are West Nile Virus, Equine Encephalitis Virus, or an Echovirus. Most cases of this type of meningitis are self-limited, occur in immunocompetent persons and resolve without significant sequelae.
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Microscopic sections showing gliosis in the motor cortex, palor of the lateral coritcospinal tracts, and neuronal loss in the anterior horns of the spinal cord are all characteristic of what disease?
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ALS.
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Schwannomas/neurofibromas are what type of nerve tumors? Are these malignant?
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These are nerve sheath tumors. Nerve sheath tumors may become malignant and metastasize. most commonly to the lungs.
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Increasing difficulty with voluntary movements, difficulty initiating movement, but not continuing movement, expressionless facies and "pill rolling" tremor are all symptoms of what disease?
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Parkinson's disease.
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Midbrain hemorrhage, arranged in a linear ventral-to-dorsal direction, leading to bilateral uncal and cerebral herniation occur by what mechanism? What is the special name for this process? Where does it happen?
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In herniation of the brainstem, branches of the basilar artery are kinked. This gives rise to hemorrhagic infarcts in the midbrain and pons. Such infarcts are called Duret hemorrhages, and typically have a ventral-to-dorsal orientation and occur in the midline or paramedian regions.
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Which cells do Meningiomas most commonly arise from? Do they occur more commonly in males or females? What regions of the brain are they most commonly found in?
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Meningiomas are typically circumscribed lesions that arise from meningothelial cell of the arachnoid and appear grossly attached to the overlying dura. They are most often seen in adult women. A parasagittal, sphenoid ridge, or subfrontal location is typical.
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Describe the most typical location for a Schwannoma to arise. Which cranial nerve is often invovled because of this location?
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The most typical location for a Schwannoma is at the cerebellopontine angle. The eighth cranial nerve (CN VIII) is most commonly involved.
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What part of the brain to Ependyomas arise in?
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Ependyomas arise in ventricles.
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A deficiency of Hexosaminidase A is characteristic of what disease?
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Tay-Sachs disease.
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Failure of formation of the fetal cranial vault results in what condition? What laboratory can indicate this sort of malformation and why?
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Failure of formation of the fetal Cranial vault results in Ancephaly, a form of severe neural tube defect. The defect allows fetal alpha-fetoprotein to enter amniotic fluid and reach the maternal circulation. Thus, presence of fetal alpha-fetoprotein in the maternal serum can be an indication of a neural tube defect.
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Maternal diabetes during pregnancy can cause CNS malformation such as what?
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One example is Holoprosencephaly.
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What is a common antecedent to demyelination in basis pontis (Central pontine myelinosis)?
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Rapid correction of hyponatremia.
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Vitamin B12 (Cobalamin) deficiency, has what effect on the spinal cord?
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A subactue combined degeneration of the spinal cord occurs slowly as a consequence of Vitamin B12 deficiency.
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Wernike-Korsakoff syndrome that accompanies chronic acoholism affects what part of the lower brain?
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The mammilary bodies and periaqueductal gray matter.
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How long does it take macrophages to clear debris of liquefactive necrosis and leave a cystic space after a recent infarction?
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This takes weeks to months after the infarcting event.
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The Neurofibrilary tangles and Amyloid plaques associated with Alzheimer's disease are best visualized via what type of stain?
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Silver stain.
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Progressive symmetric muscle weakness suggests what CNS disease?
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ALS.
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Necrosis in a perivenricular pattern, accommpanied focal calcifications are found in a newborn. What is the most likely cause of this?
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Congenital infection with CMV.
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What are the two most common neoplasms found in children in the posterior fossa of the skull? Which has a better prognosis than in adults? Is there a risk of hydropcephalus associated?
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The two most common neoplasms found at this site in children are Cystic Cerebellar Astrocytoma and Medulloblastoma (often occurring in the cerebellar midline and are composed of small, round blue cells). The type of astrocytoma usually seen at this location is a Pilocytic astrocytoma and has a better overall prognosis than do glial neoplasms in adults. Both may enlarge and block CSF flow, causing hydrocephalus.
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What is a Hemangioblastoma, where does it occur, and what blood condition is it associated with?
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A Hemangioblastoma is a rare cystic mass in adults, typically arising in the cerebellum, and may be associated with polycythemia.
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What type of patients are most likely to have a Cerebral lymphoma?
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HIV patients.
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Schwannomas typically arise in which cranial nerve?
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CN VIII
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How far in advance might an infection preclude a cerebral abscess?
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A cerebral abscess is most often the complication of an infection that occurred days to weeks earlier.
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Why is ring-enhancement a characteristic feature of an cerebral abscess on a CT scan?
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As an abscess organizes, it is ringed by fibroblasts that deposit collagen. This shows the typical ring-enhancement that appears on the CT.
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What can episodes of sudden dysarthria, feelings of weakness in the hands and legs, and dizziness all be signs of? What would a patient with these episodes be at risk for?
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These are all signs of Transient Ischemic Attacks (TIAs). A patient exhibiting these could be at risk for a stroke.
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Where does demyelination occur most commonly in patients with Multiple Sclerosis? What laboratory findings are indicative of Multiple Sclerosis?
|
The plaques of demyelination that give rise to the differing symptoms can be found in various locations, but they most often occur in periventricular white matter. CSF immunoglobulins are increased, and most patients show oligoclonal bands of IgG.
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Patients with Huntington's syndrome have atrophy and loss of neurons and gliosis in what structures of the brain?
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The Caudate, Putamen, and Globus Pallidus.
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Multiple lacunar infarcts within the basal ganglia are associated with what chronic disease?
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Hypertension.
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Describe the pathophysiology of the Leukodystrophies. What are some of the clinical findings that are associated and differentiate these diseases from others (e.g. Multiple sclerosis)?
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Leukodystrophies affect white matter extensively and cause myelin loss and abnormal accumulations of myelin. A variety of lysosomal defects lead to these disorders, which are characterized by failure of generation or maintenance of myelin. There are no discrete plaques of demyelination (as in multiple slcerosis) and there is generally sparing of subcortical myelin, such as in the U fibers.
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If someone presents with acute onset of "the worst headache of my life" and blood in the CSF with little to no other CSF findings, what is the most likely etiology of this condition? How did the blood get into the CSF?
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This presentation is most likely due to a ruptured berry aneurism. The blood entered the CSF through the subarachnoid space.
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How common are berry aneurisms? Where do they occur in the cerebral vasculature?
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About 1 in 100 persons has a saccular berry aneurism. The congenital defect occurs in the arterial media at intracerebral artery branch points, and can manifest later in life with aneurysmal dilation and possible rupture.
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What distinguishes the signs of CNS infection with Toxoplasmosis and Cerebral lymphoma in AIDS patients?
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Toxolasmosis produces abscesses that organize on the periphery to produce a bright ring on CT and MR imaging scans. Lymphomas can also produce this picture, but they generally occur as fewer larger masses, or a solitary mass.
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Will Creutzfeld-Jakob have grossly visible or radiographic findings?
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A spongiform encephalopathy such as CJD will typically not have grossly visible or radiographic findings.
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Thromboembolic disease leading to cerebral infarcts most often results from what type of disease? Give examples.
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Cardiac disease (e.g. endocarditis, mural thrombis, prosthetic valvular thrombosis)
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Basal ganglia, pontine, and cerebellar hemorrhages, and small lacunar infarcts are all associated with what chronic condition?
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Hypertension.
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Where are Hypertensive hemorrhages most likely to arise in the brain? Why do vessels here rupture?
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Hypertensive hemorrhages are most likely to arise in the basal ganglia, thalamus, cerebral white matter, pons, or cerebellum. The small intracerebral vessels are weakened by hyaline arteriolosclerosis and are prone to rupture.
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Where do metastases usually occur in the brain? How do they reach the brain?
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Tumor cells may reach the brain in the form of emboli through the cerebral arterial circulation. Most metastases occur at the gray-white junction, where narrowing and acute branching of the vessels tend to trap emboli. The distribution of the middle meningeal artery, which receives the most blood, is the most likely location.
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Thromboemboli can produce cerebral infarctions, and sometimes with hemorrhage, and usually involve what layers of the brain?
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They usually involve the cerebral cortex.
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Herniation of the Uncus involve palsy of which cranial nerve?
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Herniation of the Uncus results in a CN III palsy.
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What are Hemangioblastomas, where do they most commonly arise, and what hematologic condition are they most commonly associated with?
|
A Hemangioblastomas is a rare cystic mass in adults, typically arising in the cerebeellum, and may be associated with Polycythemia.
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What types of problems do cerebral Arteriovenous malformations cause? Who do they occur most commonly in, and how are they treated? Describe the pathophysiology of these lesions and the associated symptoms
|
Arteriovenous malformations most often occur in the cerebral hemisphere of a young adult and can be removed by a neurosurgeon. With Arteriovenous malformations there may be slow leakage of blood over time resulting in headaches, personality disturbances, mental acuity disturbances, seizures, evidence of recent and remote hemorrhage, and gliosis.
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Ependyomas are most often seen in within the ventricles or what other location?
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The distal spinal cord.
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Oligodendroglial inculsions are seen in what disease? What virus is responsible for this disease?
|
These type of inclusions are seen in Subacute Scelrosing Panencephalitis, which is associated with Rubeola (measles) infection.
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What is another name for linear, midline hemorrhages seen in the brainstem? What is the most common cause?
|
A brainstem showing linear midline hemorrhages, show Duret hemorrhages. A condition such as acute bacterial meningitis could lead to brain swelling with edema and subsequent herniation with Duret hemorrhages in the pons.
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Which differing structures do Astrocytomas affect depending on whether the patient is an adult or child?
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Astrocytomas most often involve the cerebral hemispheres of adults and cerebellum of children.
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An irregular cerebral mass, that extends across the corpus callosum involving both hemispheres, and shows areas of necrosis surrounded by nuclear pseudopalisading is most likely what type of CNS neoplasm?
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Glioblastoma multiforme.
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What is AIDS dementia complex? Which form of the HIV virus is associated? Describe the microscopic findings.
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AIDS dementia complex occurs late in the course of HIV infection. HIV-1 produces an encephalitis that is characterized by a collection of reactive microglial cells (microglial nodules). HIV-1 infected mononuclear cells, particularly macrophages, can fuse to form multinucleate cells, which are seen in association with microglial nodules.
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How is a Dandy-Walker malformation detected? What structures are involved in the malformation?
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A Dandy-Walker malformation is detected by ultrasonographic evidence of a cyst in the fourth ventricle and agenesis of the cerebellar vermis.
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What is Tuberous sclerosis?
|
Tuberous sclerosis is a rare disease that causes firm hamartomarous "tubers" in the cerebral cortex.
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Which structures are involved in an Arnold-Chiari malformation?
|
In an Arnold-Chiari malformation, there is a small posterior fossa and extension of the cerebbellum into the foramen magnum, as well as a lumbar meningomyelocele.
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What is a Germinal Matrix hemorrhage? What type of patients does it most often occur in?
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Germinal matrix hemorrhage is the most common cause of intraventricular hemorrhage in premature infants.
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What is the Germinal Matrix? When do Hemorrhages in this region most commonly occur?
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The Germinal matrix, composed of highly vascularized tissue with primitive cells, is the most prominent between 22 and 30 weeks' gestation. Hemorrhages within this area readily occur in common neonatal problems such as hypoxemia, hypercarbia, acidosis and changes in blood pressure.
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Explain how these Germinal Matrix hemorrhages can lead to hydrocephalus.
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Hemorrhages in the Germinal matrix can extend into the cerebral ventricles and from there into the subarachnoid space. Smaller hemorrhages can resolve without sequelae. With larger hemorrhages, organization of the blood in the aqueduct of Sylvius or the Fourth ventricle, or foramina of Luschka may obstruct the flow of CSF, producing hydrocephalus.
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Which neurons of the brain are most sensitive to anoxia? Which areas are the first in the Neocortex to be affected?
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The neurons that are most sensitive to anoxia reside in the hippocampus, along with the PUrkinje cells and the larger neocortical neurons. In addition, the the first areas in the neocortex to be affected are the "watershed" areas between the three major cerebral circulations, including the watershed located superiorly between the anterior cerebral and middle cerebral circulations.
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Under what types of conditions do we see "red shrunken neurons" in areas such as the hippocampal pyramidal cells, the cerebellar Perkinje cells, and the parasagittal neocortical cells pyramidal cells?
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Red shrunken neurons are typically seen in the early stages of global hypoxia, as may occur in a severe hypotensive episode.
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What type of mechanism is more likely to produce a Coup injury? Which is more likely to produce a Countercoup?
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A blow to a stationary head is more likely to produce a Coup injury directly adjacent to the site of the blow. A Countercoup type injury is more likely to occur when the moving head strikes an object and the force an the force is transmitted to the opposite side of the head. (e.g. A fall backward is most likely to produce contusions to the inferior frontal lobes, temporal tips, and inferior temporal lobes.
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Medial temporal herniation can result in what type of hemorrhage into the Pons?
|
Hemorrhage into the Pons is typical of a Duret hemorrhage, seen in medial temporal lobe herniation.
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Under what conditions is it most possible to see hemorrhage into the cerebral ventricles in infants? In adults?
|
Hemorrhage into the cerebral ventricles may occur in premature infants from germinal matrix hemorrhage; in adults, it is not common but may occur with dissection of blood from an intraparenchymal lesion.
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What is Pick disease and what symptomatic and physical findings differentiate it from Alzheimer's disease?
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Pick disease has clinical features similar to those of Alzheimer's disease, but initially it causes less memory loss and more behavioral changes. The "knifelike" gyral atrophy of Frontal and Temporal lobes and the relative sparing of parietal and occipital lobes are characteristic of Pick disease.
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What microscopic differences are found that differentiate Pick disease from Alzheimer's disease?
|
Pick bodies containing Tau protein are seen in remaining neurons that occur after atrophy in pick disease, but the neuritic plaques and neurofibrilary tangles seen in Alzheimer's disease are not increased.
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What is Leigh disease?
|
Leigh disease is one of the mitochondrial encephalopathies that can cause muscular weakness and neurological degeneration beginning at a young age.
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What is Multiple System Atrophy and what other disease does it look like? Describe the features that differentiate MSA from this other disease.
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MSA has features that overlap with those of stiatonigral degeneration, olivopontocerebellar atrophy, and Shy-Drager syndrome. Most patients with MSA exhibit symptoms similar to those of Parkinson's disease. MSA is characterized microscopically by the appearance of glial cytoplasmic inclusions.
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What type of growths occur in a person with Tuberous sclerosis?
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Growths of Tuberous sclerosis include harmatomas and neoplasms that develop throughout the body, as well as cutaneous abnormalities. Persons with tuberous sclerosis have cortical tubers, which are hamartomas of neuronal and glial tissue; other characteristic findings include renal angiomyolipomas, renal cysts, subungual fibromas, and cardiac rhabdomyomas.
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Name the enzyme deficiency associated with Krabbe disease and describe it clinical findings. What class of disease is Krabbe disease?
|
Krabbe disease is a leukodystrophy that results in deficiency of galactocerebroside B-galactosidase and an onset of neurologic deterioration in infancy.
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Differentiate the clinical findings of Neurofibromatosis Type 1 and Type 2.
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NF-1 is characterized by deforming cutaneous and visceral neurofibromas, cutaneous cafe-au-lait spots, and neurofibrosarcomas. NF-2 presents with acoustic schannomas, meningiomas, gliomas and ependymomas.
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What are the characteristic clinical findings associated with Von Hippel-Lindau disease?
|
Von Hipple-Lindau disease is characterized by hemangioblastomas in the cerebellum, retina, and spinal cord, as well as pheocromocytomas.
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Patches of skin, some leathery (shagreen patches) and some hypopigmented (ash-leaf patches), scattered over the body, in addition to findings of mental retardation, renal cysts, abdominal tumor masses, subependymal nodules, cortical foci with loss of the gray-white distinction, and a mass involving the interventricular septum is indicative of what disease?
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Tuberous sclerosis.
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What glial neoplasm has the best prognosis of all glial neoplasms and is positive for GFAP?
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Oligodendrogliomas.
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Intracranial germ cell tumors are most likely to arise from what cerebral structure?
|
Intracranial germ cell tumors are most likely to arise in the Pineal Body.
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Subacute Sclerosing Panecephalitis is a rare complication of what viral infection and leads to what clinical symptoms?
|
This is a rare complication of measles (rubeola) infection and leads to progressive mental decline, spasticity, and seizures.
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Do the Non-Hodgkin lymphomas that take root in the CNS of AIDS patients tend to be unifocal or multifocal lesions? What cell marker might they contain?
|
Multifocal. They may contain the cell marker of CD19.
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What two diseases are associated with Tau protein and how?
|
Tau protein is found in the neurofibrillary tangles of Alzheimer plaques and the Pick bodies of Pick disease.
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Dementia with Lewy Bodies (DLB) is a form of dementia with clinical features similar to those of Allzheimer's disease (AD) and Idiopathic Parkinson's disease (IPD). What protein is associated with this disease and how is a diagnosis of DLB made?
|
Mutations in the gene for Apha-synuclein have been linked to IPD, and Lewy bodies can be found in the sunbstantia nigra neurons, but clinical dementia as well as cortical Lewy bodies point to DLB.
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Cleavage of the Amyloid Precursor Protein (APP) by which two secretases produces the amyloid-beta protein associated with Alzheimer's disease? Which two secretases cleave APP into a harmless product.
|
Cleavage first by Beta-secretase and then by Gamma-secretase produces that amyloid-beta protein from APP. Cleavage first by Alpha-secretase, and then by Gamma-secretase produces a harmless protein.
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What gene mutation leads to Fredrich ataxia?
|
Mutations in the Frataxin gene lead to Friedreich ataxia, an autosomal-recessive progressive illness, generally beginning in the first decade of life.
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The CAG tinucleotide expansion repeats that underlie Huntington disease give rise to what type of poly-amino-acid repeat?
|
Polyglutamine repeats.
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What is dysarthria?
|
De-innervation of the muscles of motor speech.
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What is the difference between a speech deficit and a language deficit?
|
A language deficit is a cognitive problem. A speech deficit is a motor problem.
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What part of the brain has the richest vasculature and the highest oxygen demands?
|
The Subcortex.
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What part of the subcortex is majorly responsible for memory?
|
The Hippocampus.
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What lobe is responsible for hemineglect?
|
The Parietal lobe.
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Where are the higher cortical functions of the brain located?
|
The Frontal Lobes, which essentially act as a brake on the primitive limbic system.
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A patient who is displaying disinhibition likely has an injury to which part of the brain?
|
The Frontal Lobes.
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What are the main indications for the use of MIdazolam?
|
This is given prior to most other agents as a component of balanced anesthesia to produce relief from anxiety, and to induce sedation and amnesia to reduce the ability to recall events that occurred during sedation.
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What type of procedures is Cocaine 4% used for? What physiological effects is it used to achieve?
|
Cocaine 4% would produce similar physiological reactions to that of Lidocaine + Epinephrine. Cocaine blocks the reuptake of catecholamines, resulting in intense alpha-mediated vasoconstriction. It would be used as a topical local anesthetic applied to the nasal passage that would also produce prolonged nasal vasoconstriction. Cocaine is used for surgical procedures of the ear, nose, and throat as a component of TAC solution (Tetracaine + Adrenaline + Cocaine).
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Which drugs are commonly used in combination to produce a block of the brachial plexus?
|
Lidocaine and Epinephrine.
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How will you know which local anesthetic is an amid type LA vs. and ester-type LA?
|
The amide type LA's have a "i" before the "caine" in their name. (e.g. Lidocaine vs. Procaine).
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If epinephrine is applied to a body extremity in an analgesic solution what problems might occur? Why is this contraindicated? What is Epinephrine normally used for?
|
Epinephrine should be avoided because applying it to the body extremity can result in prolonged hypoxia and tissue damage. Epinephrine is used to prolong the duration of action of a local anesthetic, and to decrease/delay systemic absorption, but its use must be avoided in treating body extremities.
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Describe the early warning signs associated with Local Anesthetic toxicity. What are some of the late signs?
|
Early warning signs typically include symptoms such as tingling in the mouth & tongue, metallic taste in the mouth, and ringing in the ears. Late events include "unresponsiveness" during a conversation and tonic-clonic seizures.
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What is the mechanism of action of Midazolam and other benzodiazapines? How is Flumazenil used in conjunction with it?
|
MIdazolam is a benzodiazapine, which binds to a subset of GABA-A receptors that contain alpha and gamma subunits. Flumazenil is an antagonist for the benzodiazepine receptor site and can rapidly reverse the effects of Midazolam.
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What are the effects of Barbituates and Propofol on the cardiovascular system?
|
The Barbituates (such as hexabarbital and thiopental) and Propofol produce significant CV depression.
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What effect does Ketamine have on the cardiovascular system?
|
Ketamine produces increases in heart rate and blood pressure.
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What are the effects of Etomidate on the cardiovascular system?
|
Etomidate produces relatively stable cardiovascular parameters during general anesthesia with minimal CV depression.
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What general anesthetic has a short duration of action, produces little respiratory depression such that intubation is not necessary, produces analgesia and a compliant patient at relatively low doses because there is not a lot of associated sedation and is commonly used in pediatrics?
|
Ketamine with "K" for kids.
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What is a peculiar after-effect that is rarely seen in children, and more commonly observed in adults and females after being administered Ketamine?
|
Vivid dreams are a side effect that is relatively unique to Ketamine, which blocks NMDA receptors. This side effect is more common in adults, females, frequent dreamers, patients with personality disorders and patients given high doses of i.v. ketamine.
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How can the side effects of vivd dreams that can occur with the administration of Ketamine be avoided?
|
This reaction can be reduced by prophylactic use of benzodiazapines.
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What special property does the drug Propofol have? Describe its clinical indications. What are its side effects and when should it not be used?
|
Propofol has antiemetic actions as well as anesthetic actions. It is used in the induction and maintenance of anesthesia. It has a more rapid recovery compared to other barbiturates, and it tends to decreased cardiac output and cause hypotension. Propofol should not be used in children in intensive care units.
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Which two anesthetics have malignant hyperthermia associated with their use?
|
Succinylcholine and the Inhalational Halogenated general anesthetics.
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Explain how Dantrolene prevents the development of Malignant hyperthermia associated with Succinylcholine and Halogenated General anesthetic.
|
Malignant hyperthermia is a hypermetabolic state that results from a genetic mutation in skeletal muscle ryanodine receptors which causes Ca release in the presence of a trigger substance (succ. and hal. gen. anes.). Dantrolene prevents the Ca2+ release.
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If a patient has decorticate posturing, what does that say about where the neurologic lesion has likely occurred in their CNS?
|
Decorticate posturing = above the Red Nucleus
Decerebrate = at or below the Red Nucleus |
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Both pupils should constrict in response to light in either eye. What are these reflexes called?
|
The reaction from the ipsilateral eye is called the direct response and the reaction from the contralateral eye is called the consensual response.
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Describe the pathway of the Pupillary Response and which cranial nerves it involves.
|
Light --> Pupil/ CN II --> Occipital Lobe --> Edinger/Wesphal nucleus (accessory occulomotor nucleus) --> parasympathetic fibers of CN III --> iris and pupillary constriction
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|
What is usually the cause of a "blown pupil".
|
A single fixed and dilated pupil (a "blown pupil") occurs when the mesial surface of the temporal lobe pushes down through the incisura tentorium and compresses CN III usually related to increased intracranial pressure.
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Is a single blown pupil most often indicative of ipsilateral or contralateral intracranial pressure increase?
|
This most often indicates ipsilateral intracranial pressure increase.
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|
What does the presence of a Babinski sign indicate about pathology in the CNS?
|
The Babinski’s sign can indicate upper motor neuron damage to the spinal cord in the thoracic or lumbar region, or brain disease – constituting damage to the Corticospinal Tract. Occasionally, a pathological plantar reflex is the first (and only) indication of a serious disease process.
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Describe the signs and symptoms associated with compression of CN III.
|
Compression of the 3rd nerve leads to a "down and out" presentation. There is homolateral pupil dilation, ptosis, and 3rd nerve muscle palsy.
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Which cranial nerves are responsible for generating the Corneal Reflex?
|
Swiping a sterile, moistened swab across the limbus of the conrea (where it meets the sclera) stimulates CN V which connects to CN VII and causes a blink. CN's V and VII both originate in the Pons.
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CN's V and VII both work to elicit the corneal reflex. Which is responsible for the afferent messages and which is responsible for the efferent messages?
|
CN V is afferent, CN VII is efferent.
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Which cranial nerves are involved in eliciting the Oculo-vestibular response? If a person is conscious what response will they give?
|
Turning the head or lavaging one ear with cold water stimulates the vestibular part of CN VIII. The vestibular nucleus sends signals to the lateral gaze center, which in turn sends signals both to the CN VI nucleus and the CN III nucleus. This reflex arc goes all the way from the ponto-medullary junction to the very top of the mid-brain. If a person is conscious they will be able to override this reflex when asked to turn their head from side to side.
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Explain the Oculo-cephalic (Oculo-vestibular response) in one sentence.
|
Doll's eyes response: Turning the head to one side stimulates the semicircular canals in the inner ear, which sends a signal to the vestibular nucleus, which then stimulates the lateral gaze center and causes the eyes to turn in the opposite direction. This allows the ability to stay focused on an object despite head movement.
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What is the normal response to the Oculo-cephalic reflex? What part of the brain is responsible for this? What happens when the patient is comatose?
|
The normal response to turning the head is for the patient to look wherever they want. This is because the oculo-cephalic reflex is normally suppressed by the cerebral cortex. When a patient is comatose, this reflex is allowed to come through.
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The Cold Water Caloric test is used to test what reflex? Describe how it is performed and what the normal and abnormal responses are.
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The Cold Water Caloric test is used to test the Oculo-vestibular response. One ear is flushed with ice water which very strongly stimulates the horizontal semi-circular canal and causes the eyes to deviate toward the ipsilateral ear. A normal response would be a quick glance in the ipsilateral direction and then nystagmus away from the stimulus. An abnormal response is just to look towards the ipsilateral side.
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Describe the components of the Gag Response. Which CN's are involved and which are responsible for afferent and efferent branches?
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The Gag response involves swabbing the posterior pharynx stimulating the sensory component of the response (afferent CN IX), which then stimulates the motor component of the response (efferent CN X), which then causes the patient to gag. CN IX and CN X are both in the upper medulla.
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What is one of the side effects associated with Amiodarone that affects the eye?
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Deposition of corneal deposits.
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If someone has Herpes Zoster or they have HIV and they are complaining of photophobia and there eyes are burining, what is a possible reason for these symptoms? Why would a special stain be used for diagnosis?
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The patient could have Herpetic keratitis. A stain on the surface of the eye is used to visiualize dendritic formations, which protrude out from the areas of inflammation.
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Most of what we taste is actually smell. What are the actually stimuli that we can taste?
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Salt, Sugar, Bitter, Sour, and the richness of protein.
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Why is loss of sense of smell/taste after head injury, such as that sustained in a motorcycle accident, common? What else could cause loss of sense of smell/taste due to affecting the nerve described?
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This is often due to the torsion put on the brain and nerve fibers due the nature of the vehicle crash injury, with strain or damage occurring to the Olfactory Nerve (CN I) filaments in the cribiform plate. A meningioma beneath the orbital surface or the frontal lobes can push on CN I and cause similar symptoms.
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What anticonvulsant is prescribed to treat Trigeminal Neuralgia?
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Carbamazepine.
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Idiopathic Intracranial Hypertension (pseudotumor cerebri) generally affects which CN?
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Increased intracranial pressure squeezes CN VI as it follows its long course across the skull base.
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What is functions are supplied by the lower Facial Nerve (motor and sensory). What is the condition where there is loss of function of the CN VII called?
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The Facial Nerve supplies motor function to the muscles of facial expression and taste to the anterior two-thirds of the tongue. The loss of these functions, which is observed through symptoms such a sagging of one side of the face, drooling from one side of the mouth, not being able to close the eye, loss of some sensation of taste, but having the presence of an otherwise normal neurological exam is known as Bell's Palsy.
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What types of diseases tend to cause Bell's Palsy? How do you treat Bell's Palsy?
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Inflammation of the Facial Nerve due to Ramsy-Hunt syndrome, Lyme disease (basilar meningitis), HIV encephalitis, brain tumor (shwannoma). Bell's palsy is most commonly idiopathic however, and is treated with corticosteroids to enhance recovery.
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What is the nausea center for the brain?
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It is located in the medulla in the Area Postrema.
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Unlike lesions in other parts of the CNS, if there is a lesion in the cerebellum what side of the body are the symptoms going to be on? Why does this happen?
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Symptoms of a cerebellar lesion will be on the ipsilateral side. This happens because the fibers of the cerebellum to the cortex double cross as opposed to the other nerve fibers which generally only cross once.
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The blockage of PICA (the posterior inferior cerebellar artery) leads to what syndrome? Describe the symptoms associated. Which cranial nerves are likely affected?
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Blockage of PICA leads to Lateral Medullary syndrome (Wallenberg's syndrome). This symptoms include hoarse voice, slurred words, deviated uvulae, lack of palate elevation on saying "ah". This is a brainstem stroke involving CN IX and X.
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In the funduscopic exam, which side does the optic disc lie on? The nasal or lateral side?
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It lies on the nasal side.
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What does an optic cup to disc ratio greater than 50% suggest a diagnosis of?
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This suggests a diagnosis of Glaucoma.
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In what type of patients do we see CMV retinitis?
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HIV patients.
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What is a normal intraocular pressure? What is considered to be an elevated pressure?
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A normal intraocular pressure is in the teens. Elevated is considered to be a pressure greater than 21.
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Why is the fovea inside the macula preserved even when there is retinal degeneration?
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This is because the fovea is supplied by the choroidal arteries, while the rest of the retina is supplied by the retinal arteries.
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What is Minocycline induced papilledema?
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Minocycline is used to treat acne and by dentist. Minocycline can cause elevation intracranial pressure and can cause Papilledema.
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What does the presence of a "cherry red spot" tell you on a funduscopic exam?
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It tells you that the fovea is receiving blood from the choroidal arteries, but the retinal arteries are not providing blood to the rest of the retina.
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What are the two causes of retinal artery occlusion?
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Atherosclerotic thrombosis and embolic phenomenon.
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Where do flame hemorrhages occur? What causes them? What type of conditions lead to this? What are the complications associated?
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Flame hemorrhages are seen in the eye during funduscopic examination. They are caused by Retinal Vein occlusion. Hypercoagulable states, and diabetes in particular can lead to this condition. Complications include hyoxemia and neovasularization, which can ultimately lead to loss of vision.
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Will patients with vascular insults to the eye have painful or painless losses of vision? When does the opposite type of vision loss occur?
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They will have painless losses of vision. Patients with acute onset Glaucoma will have vision loss that is painful. Vision loss to corneal scratches are also very painful.
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More afferent nerve fibers of the Trigeminal nerve occur in this area than any other area of the head.
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This is the Cornea of the eye.
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Does a patient with a painful eye have an acute arterial or venous occulsion?
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NO!, these types of lesions in the eye are painless.
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What creates cotton wool spots in the retina? Which diseases is this most commonly seen in?
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The axons of the nerve fibers in the eye rot because they are ischemic and they explode. The extrude their contents into the retina and blot out the visual field. The most common disease to see this in is Diabetes mellitus because it is a common microvascular disease and the axons of these nerves are supplied by arterioles.
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What is the most common primary tumor of the eye?
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The most common primary tumor of the eye is a melanoma.
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What is a Hollenhorst plaque? Where is it found?
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A Hollenhorst plaque is a mixture of fibrin, platelets, and cholesterol and is found in the eye. This is an embolic phenomenon, not atherosclerosis.
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What type of patients have flame hemorrhages in the eye?
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Diabetic or hypertensive patients.
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What are Dot hemorrhages in the eye? What are flame hemorrhages? What are Boat hemorrhages?
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Dot hemorrhages are capillary leakage that occur very deep in the choroid. Flame hemorrhages are much more superficial along the neuronal layer. The Boat hemorrhages are deep between the retina and the vitreous.
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What is the pathophysiology of Background Diabetic Neuropathy?
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Microvascular disease.
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Explain the pathophysiology behind the neovascularization seen in the eyes of diabetics. Why is this a problem and how does it cause a patient to lose their vision?
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Like neovascularization anywhere, the vessels are not sturdy. They rupture, cause hypoxic damage, and more scar tissue and fibrin deposition. This leads to more neovascularization and repitition of this process and eventual loss of vision.
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What is the treatment for neovascularization of the retina in a diabetic patient?
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Photocoagulation with a laser.
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What are Roth spots in the eye and what condition are they most commonly associated with?
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Roth spots are essentially cotton wool spots surrounded by hemorrhage. They are most commonly associated with infective endocarditis.
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What pathologies might lead to Ischemic retinopathy?
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Sudden hyportension, poor CNS perfusion, TIA or stroke
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"Salmon patches" are seen upon funduscopic examination of patients with what type of disease?
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Sickle Cell disease.
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Cotton wool spots and hard exudates observed in funduscopic examination are classic for what disease? What are hard exudates?
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These two findings are classic for Diabetes mellitus. Hard exudates are lipid residues from damaged capillaries.
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In contrast to Hard Exudates appearing in many places in the retina, where does Drusen tend to gather around (even though they both look similar)? What pathologic process that we have not solid cure for, does Drusen indicate?
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Drusen tends to gather around the fovea. The presence of Drusen is indicative of Macular Degeneration.
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If you seen a Kaiser-Fleischer ring in someone with Wilson's disease, what organ system is likely involved that would not have been involved if just the liver were affected? What other eye sign might you find that is indicative of Wilson's disease?
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There is likely to be CNS involvment. A "Sunflower Cataract" might also be seen.
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What other eye sign besides a Kaiser-Fleischer ring, might you find that is indicative of Wilson's disease?
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A "Sunflower Cataract" might also be seen in addition to a Kaiser-Fleischer ring.
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If you find a patient with Temporal Arteritis (which can cause lower limb claudication), jaw claudication, and sudden blindness due to involvement of the retinal artery (key finding), what treatment should they be put on immediately?
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This patient with Temporal Arteritis and eye findings should be put on high dose Prednisone immediately.
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Giving supplemental oxygen to premature infants can cause what condition of the eyes?
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Neovascularization.
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What is Dacryocystitis?
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Blockage of the lacrimal duct.
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What is the underlying comorbidity is associated with Periorbital cellulitis?
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Diabetes mellitus.
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What is a complication that can follow a bout with bacterial meningitis that can lead to further CNS problems?
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The scarring following bacterial meningitis can lead to obstruction of CSF flow at the foramina of Luschka and Magendie with obstructive hydrocephalus, or alternatively scarring at the arachnoid granulations.
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Grouped atrophy of muscle, with anterior horn cell loss is associated with what disease?
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These findings are typical for Amyotrophic Lateral Sclerosis.
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Wallerian degeneration and gliosis found in a patient suggest what pathology?
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These findings suggest injury.
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If you hear of a patient that is neutropenic due to any type of immunodeficiency and middle cerebral artery thrombosis with right parietal hemorrhagic infarction what infection should you think of? Why should you not think of HSV?
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This infection could likely be due to aspergillus. Aspergillus loves to invade blood vessels and produce thrombosis. Neutropenia is a risk for aspergillosis. HSV would not produce these findings because it typically produces temporal lobe hemorrhagic lesions.
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Where in the brain does infection with HSV typically produce hemorrhagic lesions?
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HSV infection typically produces temporal lobe hemorrhagic lesions.
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A premature child, particularly in the gestation age range from 22 to 30 weeks, is at risk for what type of hemorrhage? What region of the brain does this type of hemorrhage often extend into?
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A premature child, particularly in the gestational age range from 22 to 30 weeks, is at risk for germinal matrix hemorrhage, which often extends into the intraventricular region.
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Which part (cells) of the brain experience the greatest amount of salt and water increase with cerebral edema?
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The White Matter.
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Periventricular lymphoid aggregates with cells marking with CD19 are indicative of what disease process occurring in the brain? What likely to be the greatest underlying cause of this disease?
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This person likely has Non-Hodgkin lymphoma of the brain, and is likely to be HIV positive.
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What does the cellular picture of HIV encephalopathy look like?
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Foci of multinucleated cells and macrophages in grey and white matter.
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What does Lissenecephaly describe and when is it seen?
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Lissencephaly describes a 'smooth surfaced' brain without apparent gyration (which is normal under 20 weeks gestation).
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Describe the anatomical malformations that cause the cerebellar vermis and tonsils to be displaced in Arnold-Chiari II malformation.
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Arnold-Chiari II malformation can have a neural tube defect, but there is also a small posterior fossa with an enlarged foramen magnum, into which the cerebellar vermis and tonsils are displaced.
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Describe the anatomical malformations that cause the cerebellar vermis and tonsils to be displaced in Arnold-Chiari II malformation.
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Arnold-Chiari II malformation can have a neural tube defect, but there is also a small posterior fossa with an enlarged foramen magnum, into which the cerebellar vermis and tonsils are displaced.
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Neural tube defects such as Meningocele can result in what cranial abnormalities?
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Neural tube defects lead to subtle changes in morphology based on changes in CSF flow. The leak of fluids leads to a downward shift in CNS contents. Resultant cranial abnormalities include ventriculomegaly, lemon sign, banana sign, and head measurements that are small for gestational age.
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Neural tube defects such as Meningocele can result in what cranial abnormalities?
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Neural tube defects lead to subtle changes in morphology based on changes in CSF flow. The leak of fluids leads to a downward shift in CNS contents. Resultant cranial abnormalities include ventriculomegaly, lemon sign, banana sign, and head measurements that are small for gestational age.
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What is Encephalocele and why would this result in an increase in maternal serum AFP?
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Encephalocele is a from of neural tube defect in which the occiput is not formed and herniation of the brain occurs. Alpha fetoprotein is increased in amniotic fluid or maternal serum when there is an open neural tube defect.
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What is Encephalocele and why would this result in an increase in maternal serum AFP?
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Encephalocele is a from of neural tube defect in which the occiput is not formed and herniation of the brain occurs. Alpha fetoprotein is increased in amniotic fluid or maternal serum when there is an open neural tube defect.
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Does Spina bifida occulta present prenatally with increases in AFP?
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Though there is a vertebral defect (failure of posterior arch fusion) with spina bifida occulta, there is no open defect to increase the AFP.
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Does Spina bifida occulta present prenatally with increases in AFP?
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Though there is a vertebral defect (failure of posterior arch fusion) with spina bifida occulta, there is no open defect to increase the AFP.
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Describe the cause and early symptoms of Metachromatic Leukodystrophy.
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This autosomal recessive white matter storage disease of myelin metabolism results from a deficiency of aryl sulfatase A. Motor impairment begins in early childhood.
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Describe the cause and early symptoms of Metachromatic Leukodystrophy.
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This autosomal recessive white matter storage disease of myelin metabolism results from a deficiency of aryl sulfatase A. Motor impairment begins in early childhood.
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The Parietal lobe is in the distribution of which cerebral artery?
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The Parietal lobe is in the distribution of the Middle Cerebral Artery.
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The Parietal lobe is in the distribution of which cerebral artery?
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The Parietal lobe is in the distribution of the Middle Cerebral Artery.
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Lacunar infarcts are usually a result of what type of cardiovascular condition?
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Lacunar infarcts are typically a consequence of hypertensive cerebrovascular disease.
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Lacunar infarcts are usually a result of what type of cardiovascular condition?
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Lacunar infarcts are typically a consequence of hypertensive cerebrovascular disease.
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What is Hydranencephaly?
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This is a consequense of ischemia-infarction in utero with loss of much cerebral cortex.
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What is Hydranencephaly?
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This is a consequense of ischemia-infarction in utero with loss of much cerebral cortex.
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With short hypotensive events, which areas of the brain will be most sensitive to ischemia? What location of infarction is most likely?
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Linear parasagital infarction is more likely to occur than other types of infarction during a hypotensive episode. The most sensitive areas of the brain to ischemia will be the "watershed" areas between the anterior and middle cerebral arterial circulations.
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With short hypotensive events, which areas of the brain will be most sensitive to ischemia? What location of infarction is most likely?
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Linear parasagital infarction is more likely to occur than other types of infarction during a hypotensive episode. The most sensitive areas of the brain to ischemia will be the "watershed" areas between the anterior and middle cerebral arterial circulations.
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What is von Recklinghausen disease?
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This disease is characterized by development of a variety of neoplasms including neurofibromas and sometimes gliomas.
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Describe Werdnig-Hoffman disease. What patient population does it affect most? Describe its symptoms. What other disease can it look like because of the cells that it affects?
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This is a pediatric disease, typically presenting as a "floppy infant" with progressive muscular weakness. there is also loss of anterior horn cells with Werndig-Hoffman disease. Thus, this can look like Polio.
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Why is Diffuse Lewy Body disease similar to and different than Parkinson disease?
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Diffuse Lewy Body disease is sort of a mix between Parkinson and Alzheimer disease. DLB can have movement problems similar to Parkinson disease and Dementia similar to Alzheimer disease.
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What can be a viral cause of Guillain-Barre syndrome?
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CMV respiratory infection.
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What part of the spinal cord can B12 deficiency affect?
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In B12 deficiency there is demyelination of the dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts.
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What part of the spinal cord is affected in neruosyphilis?
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Atrophy of the dorsal columns occurs in neurosyphilis. This helps to explain the term 'tabes dorsalis'.
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What is the most common cause of peripheral neuropathy in the U.S. and Europe?
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Diabetes mellitus.
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Dementia along with myoclonus makes you think of what disease?
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Spongiform encephalopathy - Creutzfeldt-Jakob disease.
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Encephalopathy and neruopathy, along with anemia, renal abnormalities, and abdominal pain, makes you think of what type of poisoning?
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Lead poisoning.
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What is Leigh disease? How is it inherited? Which patient population does it affect?
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Leigh disease is a form of mitochondrial encephalopathy that appears at a young age.
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What are the most common sources for metastases to the brain?
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Lungs, breast, skin, kidney, GI.
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Where are negri bodies that follow infection with Rabies seen most prominently in the brain? What color are they?
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Negri bodies are Eosinophilic intracytoplasmic inclusions seen most prominently in the hippocampus and cerebellum.
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Lumbar meningomyelococele is frequently associated with what other malformation?
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A Chiari II malformation
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A GFAP positive tumor suggests what CNS origin?
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This suggests a Glial origin.
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If a patient has infarction of the left Posterior Inferior Cerebellar Artery what are the symptoms that might be associated?
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Nystagmus, left miosis and ptosis. Inability to feel pain or temperature in the left side of the face and in the right side of the body; difficulty speaking and salivary dribbling; normal sensorium and no motor deficits.
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What are the sections of the CNS that are supplied by the PICA? What is an infarction of the vessel called?
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The PICA supplies the lateral portion of the medulla, the spinothalamic tracts, and the inferior surface of the cerebellum. An infarction of this vessel is called Lateral Medullary Syndrome.
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The inability to feel pain and temperature on one side of the face are due to irritation of which of the cranial nerve tracts?
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CN V.
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Hemianopia is due to involvement of what part of the cortex?
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Calcarine cortex in the occipital lobe.
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What is the difference in signs and symptoms between Alzheimer's and Pick's disease?
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Pick's disease presents with greater behavioral abnormalities and also language problems.
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In Alzheimer's disease which etter correlates with clinical impairment: quantitiy of NF tangles or the quantity of Neuritic Plaques?
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Quantity of NF tangles.
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In what disease do you find Hirano bodies?
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Alzheimer's disease.
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Is clonus considered an upper or lower motor neuron sign?
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Upper motor neuron sign.
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Episodic bouts of optic neuritis, unilateral vision impairment, incontinence in a middle aged female make you think of what disease?
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Demyelinating disease- Multiple sclerosis.
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Luxol fast blur PAS stain would be used to visualize what aspect of nerves?
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Luxol fast blue PAS stain is a stain for myelin.
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A child has difficulty walking, hand clumbsiness, decreased visual acuity, kyphoscoliosis, and a left foot deformity. He also is neurologically impaired with impaired proprioception, vibration sense,temperature sensation. He also exibits a wide-based gait. What does he have?
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Friedreich's ataxia.
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What type of cancer is Ataxia Telangectasia associated with?
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Ataxia telangectasia is associated with T-cell lymphomas/leukemia.
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How is Friedreich's Ataxia inherited? What other diseases is it associated with? In one sentence, describe the course of the disease.
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Friedreich's Ataxia is an autosomal recessive disease. About 10% of patients develop diabetes mellitus, and many develop cardiac disease and congestive heart failure. Clinically, it is a progressive disease that ends with most patients dying from cardiac disease or recurrent pulmonary infections.
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Negri bodies within cerebellar Purkinje cells are pathognomonic of what viral infection?
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Rabies.
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Olfactory haluncinations are commonly seen in what viral encephalitis?
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Herpes encephalitis.
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What type of encephalitis can present with seizures, confusion, stupor, and may have neurologic findings as ocular palsies and reflex asymmetry?
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Arbovirus encephalitis.
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What is one of the first parts of the brain that Alzheimer's attacks?
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The hippocampus
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EEG shows triphasic waves with sharpened outlines that occur once every second means what?
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Spongiform encephalopathy.
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Toxoplasmosis produces what type of brain disease?
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Meningoencephalitis.
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What type of organism is Toxoplasmosis? What is the definitive host? How are humans most commonly infected?
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Toxoplasmosis is a protozoan organism. The definitive hosts are cats, and human infections are due to consumption of undercooked contaminated meat.
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What type of disease can congential Toxoplasmosis infection produce?
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Encephalitis, microcephaly, chorioretinitis, and mental retardaion.
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What part of the spinal cord is affected most in a patient with Tabes dorsalis?
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In Tabes dorsalis we are most likely to see axonal loss in the posterior columns.
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Can Neuroborreliosis present as a meningitis? What type of neuropathy? How can the organism that causes this disease be identified? What histological features may be found?
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Neuroborreliosis may present as aseptic meningitis and as a polyneuropathy. Organisms may be identified with a Dieterle stain, and histologically, vasculitis and granulomas may be found.
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What are some of the morophological feature that may be seen in neurosyphilis?
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The morphological features of neurosyphilis include obliterative endarteritis in leptomeninges, cerebral gummas, spirochetal invasion of the cerebral cortex, and granular ependymitis.
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What morphologic changes might you expect to see in the brain of a person infected with Rabies virus?
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Eosinophilic cytoplasmic inclusions in pyramidal neurons of the hippocampus, perivascular lymphocytosis in the brain stem, and Negri bodies in Purkinje cells of the cerebellum.
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Describe some of the microscopic findings of a schwannnoma.
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Microscopically this lesion may show Antoni A and Antoni B type tissue, verocay bodies, palisading, or degenerative changes.
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Where do Craniopharyngioma tumors arise from? How do these tumors most commonly present clinically, in adults? What type of tumor is it?
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The Remnants of Rathke's pouch. These tumors most commonly present clinically with visual disturbances in adults. This is a benign epithelial tumor.
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The presence of calcifications on scans of Craniopharyngiomas is important in ruling out what other tumor? What type of symptoms can patients with these tumors present with, especially younger patients? How are these tumors treated?
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The presence of calcifications is important in ruling out Hypothalamic Pilocytic Astrocytoma. Patients with these tumors can present with diabetes insipidus, growth retardation, headaches and bitemporal hemianopsia. Surgical partial resection is the usual treatment, while needle aspiration with radiation is an alternative treatment.
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Which tumor has a better prognosis: Oligodendroglioma or Astrocytoma?
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Oligodendroglioma does.
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If you see a mass that you suspect is a Medulloblastoma in a child, what other tumor should be on your diagnosis?
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Pilocytic astrocytoma. Both types of tumors arise in the cerebellum in children.
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Meningiomas are associated with what other tumerous disease?
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Neurofibromatosis Type II.
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What type of CNS tumor gives us the "classic fried egg" appearance? What is special about imaging of this tumor type? Is this a malignant or benign tumor?
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This describes an Oligodendrocytoma. Radiographically these tumors can show cystic areas, CALCIFICATIONS, surrounding edmea, and solid tumors. Although relatively benign, these tumors can undergo malignant transformation.
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What ethnic group of patients more commonly develops malignant ocular tumors? What structures do these tumors arise from?
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Ocular melanomas represent the most common malignant ocular tumors in whites. They may arise from the uvea, retina, ciliary body, or iris of the eye.
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What types of ocular melanomas are there and which has a worse prognosis? Are these melanomas capable of metastases and if so, where is the most common location?
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Intraocular melanoma, spindle cell types , have a better prognosis than ones with an epithelioid component and melanomas with prominent necrosis. Intraocular melanomas do not have the same pattern of metastases as cutaneous melanomas. When intraocular melanomas metastasize they usually metastasize to the liver first.
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Mutations of the Rb gene predispose individuals to what type of tumors?
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Retinoblastoma, Osteosarcoma, and Glioblastoma multiforme.
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Do patients with retinoblastoma usually have bilateral or unilateral tumors? Do most patients that develop retinoblastoma have a family history?
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Patients typically have bilateral tumors, and most patients have no previous family history.
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Patients with the mutant Rb gene are at greater risk of developing what childhood or adult cancer?
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Childhood Retinoblastoma and adult Osteosarcoma
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What is a Lisch nodule and what disease is it found in?
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A Lisch nodule is a pigmented hamartomatous nevus (a type of benign tumor) affecting the iris. It is associated with NF-1
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Name the diagnostic criteria for NF-1
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Siix or more cafe au lait spots, two or more neurofibromas, freckling in the axillary or inguinal regions, or Lisch nodules.
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A patient with NF-2 is at increased risk of having what type of tumors?
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Meningiomas, Schwannomas, Meningioaniomatosis, and Hamartomas.
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Tuberous sclerosis is an autosomal dominant disease associated with what genetic mutation(s)?
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9q34 and 16p13.3
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Patients with Tuberous sclerosis may develop what unique tumors? Where is the classic location for this tumor? What does the term "tuber" refer to in this disease?
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Subependymal giant cell astrocytomas. The classic location for this tumor is beneath the ventricular surface. The term tuber in this disease refers to thickened gyri.
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What general class of neoplasms do we see associated with Tuberous sclerosis? Name some of the specific examples.
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This syndrome is characterized by Hamartomas and benign tumors. Specifically we see Angiomyolipomas, Cardiac myomas, Retinal hamartomas, and Angiofibromas.
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von Hippal Lindau disease is associated with what genetic mutation? Where are the vascular lesions in this disease typically located?
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3p25-26. The vascular lesions are typically located in the Cerebellar lobes and the Retina.
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Patients with von Hippal Lindau disease have a strong propensity for developing tumors of what organs?
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Retina, Kidney, Cerebellum, and Pancreas.
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Name four conditions that are associated with von Hippal Lindau disease.
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Renal cell carcinoma, thus increased levels of Erythropoeitin, Cysts of the liver, pancreas and kidney, and Hemangioblastomas.
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Pheochromocytomas are associated with what two diseases that we learned about in the CNS block?
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NF-2, and von Hippel-Lindau disease.
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What three things should you think about when you think of f von Hipple-Lindau disease? Where do cysts develope?
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Cerebellum, Retinas, and Pheochromocytoma. Cysts develop in the kidney and pancreas.
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When you hear undifferentiated primitive neuroectodermal cells what CNS tumor do you think of?
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Medulloblastoma.
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What is the most common CNS neoplasm in immunocompromised patients?
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Primary CNS lymphoma.
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What CNS tumor is commonly cystic, and histologically contains Rosenthal fibers?
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Pilocytic astrocytoma.
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Large multinucleated histiocytes (globoid cells)make you think of what disease?
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Krabbe disease.
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A Colloid cyst make cause what problems in the brain?
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Non-communicating hydrocephalus secondary to obstruction of the foramina of Monro.
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This lesion may produce positional headaches, and can cause non-communicating hydrocephalus secondary to obstruction of the foramina of Monro.
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Colloid cyst.
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What CNS tumor is associated with Rosettes and pseudorossettes?
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Ependymomas.
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Abnormalities on Chromosome #22 are associated with what diseases?
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Meningiomas and NF-II.
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Abnormalities on Chromosome #17 are associated with what diseases?
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NF-I, Lissencephaly, and Medulloblastoma.
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Abnormalities on Chromosome #3 are associated with what diseases?
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von Hippel Lindau syndrome.
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Abnormalities on Chromosome #9 are associated with what diseases?
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Tuberous sclerosis, and Friedreich's ataxia.
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Abnormalities on Chromosome #19 are associated with what diseases?
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Allele epsilon of the ApoE4 gene is on Chromosome #19 and is associated with Alzheimer's.
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What is the cell of origin of Glioblastoma multiforme?
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Astrocytes.
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What is the cell of origin of Meningioma, secretory variant?
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Meningothelial cells.
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What is the cell of origin of Schwannoma?
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Neural crest.
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What is the cell of origin of Craniophayngiomas and Pituitary adenomas?
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Rathke pouch remnants.
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What is the cell of origin of Medulloblastoma?
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Primitive undifferentiated neuroectodermal cells.
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