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338 Cards in this Set
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- 3rd side (hint)
What are neural tube defects
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A group of disorders characterized by incomplete closure of the neural tube in early gestation which results in dorsal midline defects at birth
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What structures can be involved with neural tube defects
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Vertebrae, skull, brain, spinal cord, and meninges
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Neural tube defects are associated with an increase in what in the maternal serum
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α-fetoprotein
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What are 3 possible reasons for neural tube defects
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Presence of pathologic state in utero at time of neural tube closure (metabolic, nutritive, toxic, or infective causes)
Faulty implantation of placenta Genetic abnormalities |
None
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What is the most common neural tube defect
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Spina bifida
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What is the defect in spina bifida
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Failure of posterior vertebral arches to close
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What is spina bifida occulta
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Same as spina bifida, but with no clinical abnormalities. Often there are only one or two vertebral arch defects
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None
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What physical finding can be the only clue to spina bifida occulta
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Doral midline tuft of hair, overlying the site of defective vertebra
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What malformation can be associated with lumbar spina bifida
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Arnold-Chiari malformation
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What is a meningocele
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Herniation of meninges (arachnoid, dura) through a vertebral defect
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What is meningomyelocele
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Herniation of meninges and spinal cord through a vertebral defect
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What is the most severe neural tube defect
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Anencephaly
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Describe the clinical features of anencephaly
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Diminished or absent fetal brain tissue, usually associated with absence of overlying skull. Cerebral hemispheres, diencephalon, and midbrain can also be absent
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None
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In anencephaly, what is exposed instead of fetal brain tissue
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A mass of undifferentiated vascular tissue
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What is hydrocephalus
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Increased volume of cerebrospinal fluid within the cranial cavity
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Name 4 types of hydrocephalus
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Internal hydrocephalus
External hydrocephalus Communicating hydrocephalus Noncommunicating hydrocephalus |
None
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What is the difference between internal and external hydrocephalus
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Internal: Increased CSF in the ventricles
External: Increased CSF in the subarachnoid space |
None
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What is the difference between communicating and noncommunicating hydrocephalus
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Communicating: CSF can freely flow between ventricles and spinal subarachnoid space
Noncommunicating: The flow of CSF is obstructed between the ventricles and spinal subarachnoid space, causing proximal dilation of the ventricular system |
None
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What can often be seen in infants with hydrocephalus
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Marked enlargement of the skull
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Why does enlargement of the skull occur in infants with hydrocephalus
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Cranial sutures are not closed yet
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What are the causes of noncommunicating hydrocephalus
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Anything can obstruct the CSF flow, including:
Congenital malformations Inflammation Tumors Choroid plexus papilloma (rare; produces excess CSF) |
None
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What is hydrocephalus ex vacuo
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Apparent enlargement of ventricles because of decreased cerebral mass, not because of obstruction or increased CSF production
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Name two diseases characterized by decreased cerebral mass
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Ischemic brain atrophy
Alzheimer disease (advanced) |
None
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What is Arnold-Chiari malformation
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Caudal (downward) displacement of medulla and cerebellum through foramen magnum into the cervical vertebral canal. It can be associated with lumbar spina bifida
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What defect is commonly associated with Arnold-Chiari malformation
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Thoracolumbar meningomyelocele
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Name 2 consequences of Arnold-Chiari malformation
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Pressure atrophy of displaced brain tissue
Hydrocephalus, resulting from obstruction of CSF outflow tract |
None
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What is fetal alcohol syndrome
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A spectrum of characteristic dysmorphic features and developmental defects resulting from maternal alcohol intake during pregnancy
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Name 6 features that can be found in fetal alcohol syndrome
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Interuterine growth retardation and subsequent growth failure
Microcephaly Mental retardation Micrognathia (small mandible) Short palpebral fissures Atrial septal defect |
None
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What is Bourneville disease
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Aother name for tuberous sclerosis syndrome
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What is the pathogenesis of the tuberous sclerosis syndrome
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Disorder of migration and arrested maturation of neural ectoderm, resulting in hamartomas (tubers) of the brain, retina, and viscera
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Name 4 features of tuberous sclerosis syndrome
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Multiple tubers in the cerebral cortex and periventricular areas
Adenoma sebaceum of the skin (primarily facial) Angiomyolipoma of the kidney Rhabdomyoma of the heart |
None
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What is the pathology of the “tuber” in tuberous sclerosis
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Proliferations of atypical multinucleated astrocytes, appearing macroscopically as small, white nodules
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What is seen on the skin of a tuberous sclerosis patient under an ultraviolet Wood lamp
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Discrete areas of hypopigmentation known as “ash-leaf spots”
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None
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What is the common clinical presentation of patients with tuberous sclerosis syndrome
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Infantile seizures and mental retardation
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What is agenesis of the corpus callosum
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Complete or partial absence of the corpus callosum, wherein the only connection between the 2 cerebral hemispheres is at the brainstem. It is often asymptomatic
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What is von Recklinghausen disease
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An autosomal dominant disorder characterized by café au lait spots, multiple cutaneous neurofibromas, and Lisch nodules
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What is another name for von Recklinhausen disease
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Neurofibromatosis
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What are café au lait spots
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Small areas with irregular margins of increased pigmentation on the skin
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What are Lisch nodules
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Pigmented nodules of the iris, consisting of melanocytes
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Name the 2 types of neurofibromatosis, and the characteristics associated with each
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Peripheral (Type 1): Skin lesions, dermal and peripheral nerve tumors
Central (Type II): Bilateral schwannomas of the acoustic nerve, and associated meningiomas, gliomas, and neurofibromas |
None
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Name 4 hereditary degenerative disorders of the nervous system and identify their pattern of inheritance
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Huntington disease (AD)
Wilson disease (AR) Lipid storage diseases (eg Tay-Sachs disease and Niemann-Pick disease) Friedrich ataxia (AR) |
None
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What is the most common disorder of the central nervous system
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Cerebrovascular disease; third most common cause of death in the US
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Name 2 major categories of cerebrovascular disease
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Infarction (more common)
Hemorrhage |
None
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What are transient ischemic attacks
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Episodes of focal neurologic defects caused by temporary lack of cerebral blood flow, with complete resolution of deficits
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How long do transient ischemic attacks last
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Normally, a few minutes, but they can last up to 24 hours
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What are some common neurologic defects seen in transient ischemic attacks
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Amaurosis fugax (temporary blindness), hemiplegia, and other cranial nerve defects
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None
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If transient ischemic attacks are present, there is increased risk for what
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Increased risk of cerebral infarct (stroke)
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What are 2 mechanisms of brain infarction
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Occlusion of the arterial blood supply to the brain from thrombosis, or embolism
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What is the most common cause of vascular thrombosis
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Atherosclerotic plaques in blood vessels. They can rupture and initiate the coagulation cascade
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Name the 3 most common sites of cerebral thrombosis
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Bifurcation site of common carotid into internal carotid and external carotid arteries
Branching sites of circle of Willis, especially the middle cerebral artery Vertebral and basilar arteries, especially bifurcation sites |
None
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What clinical findings can be seen with arterial obstruction of the middle cerebral artery
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Findings depend on extent of collateral circulation, but may include:
Contralateral paralysis Motor and sensory deficits Aphasias |
None
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Name 5 causes of embolic occlusion
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Cardiac mural thrombi
Valvular vegetations, seen in infective endocarditis Tumor cells Air bubbles Fat droplets |
None
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What is the most common site of embolic occlusions
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Middle cerebral artery
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What are lacunae
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Small healed infarcts that appear grossly as “pits” in brain matter
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What are some clinical manifestations of lacunar strokes if the obstruction of vessels occurs in the internal capsule
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Pure motor deficits
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What are some clinical manifestations of lacunar strokes if the obstruction of vessels occurs in the thalamus
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Pure sensory deficits
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Where are the 2 types of hemorrhagic brain disease
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Intracerebral hemorrhage (brain substance)
Subarachnoid hemorrhage (subarachnoid space) |
None
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What are 4 predisposing conditions that increase the risk of intracerebral hemorrhage
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Hypertension (most common)
Coagulation disorders, including thrombocytopenia Hemorrhage within primary or metastatic cerebral neoplasms Leukemia, in which neoplastic cells obstruct small vessels |
None
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Where are the 4 most common sites of intracerebral hemorrhage
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Frontal lobe
Basal ganglia Cerebellum Pons |
None
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What develops in the brain as a result of chronic hypertension
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Charcot-Bouchard aneurysms
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None
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Are Charcot-Bouchard aneurysms likely to rupture into brain parenchyma
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Yes
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What increases risk of Berry aneurysms rupturing
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Hypertension
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What type of aneurysm can rupture into the subarachnoid space
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Berry aneurysms, commonly found in the circle of Willis
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Name 3 other causes of subarachnoid hemorrhage
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Arteriovenous malformation
Trauma Hemorrhagic diatheses |
None
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What is the most common cause of subarachnoid hemorrhage
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Trauma
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What is the #1 cause of most head and spine injuries
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Motor vehicle accidents
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Name 4 types of injury to the brain in head trauma
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Intracranial hemorrhage (epidural, subdural, subarachnoid)
Concussion Contusion Laceration |
None
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What artery is injured in an epidural hemorrhage
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Middle meningeal artery
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How is the middle meningeal artery injured
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Laceration from skull fracture
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What is the clinical presentation of epidural hemorrhage
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First, loss of consciousness immediately after the injury. Then, a lucid interval, followed by acute signs of increased intracranial pressure
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What causes intracranial pressure in an epidural hematoma
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Hematoma external to the dura mater presses inward, causing local brain compression
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What is the treatment for epidural hemorrhage
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Immediate surgical decompression to prevent subtentorial herniation
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What vessels are injured in a subdural hematoma
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Most commonly, the bridging veins from the cerebrum to venous sinuses in the dura mater
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None
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Name 2 causes of subdural hematoma
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Blow to the head, commonly in the frontal or occipital regions; Birth injury
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What is the clinical presentation of subdural hematoma
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More insidious signs of decreasing mental status and enlargement of the hematoma can occur days to weeks after seemingly insignificant head injury
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Does the enlargement in a subdural hematoma result from the bridging vein still hemorrhaging days to weeks after the injury
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No; the enlarging hematoma is thought to result from osmotic properties of water movement into the collection of blood
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None
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Describe the course of a concussion
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It is usually associated with loss of consciousness, characterized by temporary widespread brain paralysis without obvious organic pathology, usually associated with complete recovery
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What is hypothesized to be the mechanism of injury of a concussion
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Rotational or shearing strains on the brain
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What is a contusion brain injury
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Linked to a “bruise” on the brain, it results from torn capillaries from a blow to the calvarium
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What are 2 types of contusions
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Coup: Lesion is located directly beneath area of impact
Contrecoup: Lesion is opposite to the area of impact |
None
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What is the clinical presentation of a contusion
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Loss of consciousness, possibly progressing to coma or death
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What is the gross appearance of an acute contusion
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Swollen edematous gyri
Petechial hemorrhages |
None
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What is the gross appearance of an old contusion injury
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Sunken areas of brain, with small cysts
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What is the microscopic appearance of an old contusion injury
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Gliosis
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What is the microscopic appearance of an acute contusion injury
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Edematous cortex and subcortical white matter; fresh pericapillary hemorrhages
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What are Duret hemorrhages
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The petechiae seen in acute contusions
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What is a cord crush injury
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Compression and contusion of the spinal cord
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What is the common mechanism of injury in a cord crush injury
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Dislocation of vertebra, most commonly in lower cervical area, following forcible flexion as in a motor vehicle accident
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What is herniated in a “slipped disk”
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Nucleus pulposus, the center of the intervertebral disc, through a defect in the annulus fibrosis, causing pressure on nerve roots
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What is the most common area for a slipped disk
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Lumbrosacral: L4-5 or L5-S1 discs
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What is the common clinical presentation of a slipped disk
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Sciatica, or lower back pain after mild or moderate trauma
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What is the most common bacterial infection of the CNS
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Bacterial meningitis
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In what population is bacterial meningitis most common
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Children
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Name 6 causative microorganisms of bacterial meningitis
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Neisseria meningitidis
Streptococcus pneumoniae Haemophilus influenzae type b Eschericia coli Group B Streptococcus Listeria monocytogenes |
None
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What organisms cause bacterial meningitis in newborns
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Group B Strep and E. coli
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What organisms cause bacterial meningitis in children
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S. Pneumoniae and H. influenzae
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What organisms cause bacterial meningitis in adolescents and adults
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Meningococcus and pneumococcus
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What organisms cause bacterial meningitis in the elderly
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Listeria monocytogenes and pneumococcus
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How do pathogens obtain access to the meninges
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Direct invasion (from facial sinuses or middle ear); Hematogenous seeding
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What are the 3 classic clinical signs of bacterial meningitis
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Mental status changes
Fever Nuchal rigidity (neck stiffness) |
None
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What are some other signs of clinical meningitis
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Vomiting, headache, confusion, and seizures
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What are the 3 findings in CSF diagnostic for bacterial meningitis
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Increased protein
Decreased glucose (<2/3 serum glucose) Many polymorphonuclear neutrophils (PMNs) |
None
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What will be noted about the opening pressure on lumbar puncture for a patient with bacterial meningitis
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Increased pressure
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What imaging test should be performed for bacterial meningitis if papilledema or focal neurologic signs are present
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Head CT scan before lumbar puncture, to rule out increased intracranial pressure from hydrocephalus or mass lesion
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What can occur if a mass lesion is present
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Risk for brain herniation into spinal canal when pressure is released at the site of a lumbar puncture
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What are the gross pathologic findings of bacterial meningitis in the subarachnoid space
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Purulent exudate
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What is the most common etiology of cerebral abscess
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Secondary infection from primary sources elsewhere in the body
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Name 5 common primary sources of cerebral abscess
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Otitis media
Frontal sinusitis Mastoiditis Lung abscess, empyema, or other bronchopulmonary infection Infective bacterial endocarditis |
None
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What are the clinical symptoms of cerebral abscesses
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Increased ICP and source of primary infection
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What are the CSF findings of cerebral abscesses
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Increased opening pressure, slightly increased protein and lymphocytes, and no change in glucose
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What organisms are seen in the CSF with brain abscesses
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None are usually seen, unless rupture of abscess has occurred
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What are the gross pathologic findings with brain abscesses
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Cavitary lesion in the brain filled with thick exudate, walled off by edematous tissue
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What can occur if infection spreads beyond abscess walls
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Encephalitis
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What part of the nervous system is the most common site of tuberculous infection
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Meninges
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How do mycobacteria gain access to the meninges
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Miliary dissemination from another source elsewhere in the body
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What are the clinical features of tuberculous infection of the meninges
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Gradual onset of anorexia, weight loss, and night sweats. Patient may also have mood changes, periods of drowsiness and delirium, and intermittent lucid intervals
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What are the CSF findings with meningeal tuberculosis
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Increased lymphocytes
Significantly increased protein Decreased glucose Acid-fast bacilli in CSF |
None
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What are the gross pathologic findings in tubercular meningitis
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Gray-white thin exudate in meninges, pooling in the basilar cisterns and sylvian fissure; Tubercles (round white nodules) at the periphery
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What is the microscopic pathology in meningeal tuberculosis
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Granulomas composed of lymphocytes and large mononuclear cells; Tubercle bacilli
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What are common pathogens of fungal infection in the CNS
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Cryptococcus neoformans; Coccidioides immitis; Aspergillus; Histoplasma
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What predisposes an individual to fungal infection
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Impaired immunity
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What is toxoplasmosis
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Parasitic infection in which the pathogen is Toxoplasma gondii
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What is the source of toxoplasmosis in neonates
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Transmission transplacentally from infected mother
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What are some modes of toxoplasmosis infection
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Ingestion of foods contaminated by animal urine or feces; Contamination from household pets (ie cats)
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What are three neurologic characteristics of congenital toxoplasmosis infection
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Hydrocephalus
Microcephaly Seizures |
None
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What is the characteristic finding of toxoplasmosis on radiologic studies
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Periventricular calcifications
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Name the 3 areas of toxoplasma involvement in the brain
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Cerebral cortex; Basal ganglia; Retina
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What is the most common site of toxological infection in adults
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Lymph nodes
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What is another name for viral meningitis
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Aseptic meningitis
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How are the clinical findings in viral meningitis different from bacterial meningitis
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None; they are the same: fever, headache, and nuchal rigidity
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What are the CSF findings in viral meningitis
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Increased lymphocytes
Moderate increase in protein Normal glucose |
None
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What are the changes found in the brain substance occurring in meningoencephalitis or encephalitis
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Perivascular cuffing (mononuclear cell infiltrate in the Virchow-Robin spaces around the vasculature)
Inclusion bodies in neurons or glial cells Glial nodules (nonspecific proliferation of microglia) |
None
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Name 6 examples of CNS viral infection
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Arbovirus encephalitis (St. Louis, Eastern equine, Western equine); Herpes simplex; Poliomyelitis; Rabies; Cytomegalovirus; HIV
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What part of the brain is affected in Herpes simplex encephalitis
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Temporal lobe
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What happens to the brain in Herpes simplex encephalitis
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It becomes swollen, hemorrhagic, and necrotic
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What deteriorates in poliomyelitis
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Anterior horn cells of spinal cord
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What are the clinical manifestations of rabies
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Severe encephalitis with increased excitability of the CNS. Muscle contractions and convulsions can occur after minimal stimuli
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What are three histologic findings of rabies
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Neuronal degeneration
Perivascular cuffing in brainstem and spinal cord Negri bodies (eosinophilic intracytoplasmic inclusion bodies) |
None
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Where are Negri bodies found
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Hippocampus and cerebellum (Purkinje cells)
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What is the characteristic histology of CMV infection
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Giant cells with eosinophilic inclusions involving nucleus and cytoplasm
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What can be seen on radiologic evaluation of the brain in CMV infection
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Periventricular calcifications
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What is the most common clinical presentation of HIV nervous system involvement
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AIDS dementia complex
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Name 4 examples of suspected slow virus infection
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Kuru; Creutzfeldt-Jakob disease; Subacute sclerosing panencephalitis; Progressive multifocal leukoencephalopathy
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What characterizes slow virus infections
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Long incubation period, little inflammatory response, and progressive deterioration
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What is the histology of slow virus infections
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Spongiosis, with numerous clusters of small cysts in the CNS gray matter
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What 2 diseases do you suspect if dementia occurs acutely
|
Creutzfeldt-Jakob disease
Normal pressure hydrocephalus |
None
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Where was kuru first documented
|
A cannibal tribe in New Guinea, which ritualized the practice of consuming the human brain
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What is subacute sclerosing panencephalitis
|
Persistent infections with measles virus, usually infected in infancy but asymptomatic until late childhood or early adolescence. Prognosis is slowly progressive and usually fatal
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What is atypical about the measles virus
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Lack of M component of the virus, responsible for extracellular spread; perhaps responsible for slow infection
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What is PML
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Rapidly progressive demyelination in multiple foci throughout the brain
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What percentage of all nervous system disorders are neoplasms
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About 10%
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What is the incidence of neoplastic disease of the spinal cord
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Very rare
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In adults, are the majority of intracranial neoplasms above or below the tentorium
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Supratentorial
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In children, are the majority of intracranial neoplasms above or below the tentorium
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Infratentorial
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Are CNS tumors the most common malignancy in children
|
No, but they are the 2nd most common after leukemia
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None
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Where do most primary malignant CNS tumors metastasize
|
They usually don’t metastasize
|
None
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What can be some direct effects of intracranial tumors
|
Neurologic dysfunction, with focal deficits depending on location of neoplasm; Electrically unstable neurons, with predisposition to epileptiform activity
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Name 6 secondary effects of intracranial tumors
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Brain edema; Compression with resultant deficiency of vascular supply; Ischemia; Necrosis; Herniation of brain and/or cerebellar tonsils; Hydrocephalus
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What can often be seen on funduscopic examination in a patient with intracranial tumors
|
Papilledema (swelling caused by edema of optic nerve papillae) and retinal vein engorgement
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Name the 4 most common intracranial tumors in adults
|
Glioblastoma multiforme
Metastatic tumors (from extracranial primary sites) Meningioma Acoustic neuroma |
None
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Name the 4 most common intracranial tumors in children
|
Medulloblastoma
Ependymoma Craniopharyngioma Astrocytoma |
None
|
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Name 3 other neoplasms of the CNS found in children
|
Retinoblastoma
Neuroblastoma Hemangioblastoma |
None
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How does a glial tumor grow differently from a non-glial tumor
|
Glial tumors grow by infiltration, and thus cannot be completely removed. Non-glial tumors grow by expansion and are more likely to be totally resected
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What is the function of a normal astrocyte
|
In reaction to injury, astrocytes expand their cytoplasm and form glial fibrils
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What is the most common location of astrocytomas in adults
|
Central white matter of the cerebrum
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What is the most common location of astrocytomas in children
|
Cerebellum
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How are astrocytomas characterized
|
Based on histology; Grade I-Grade IV
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What is the treatment of astrocytoma
|
Surgical resection, with excellent prognosis if completely removed
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What is another name for Grade IV astrocytoma
|
Glioblastoma multiforme, the most common primary intracranial neoplasm
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What is the peak age group for glioblastoma multiforme
|
Later middle age
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Describe the histology of glioblastoma multiforme
|
Marked anaplasia and pleomorphism
Vascular changes with endothelial hyperplasia Many mitoses |
None
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What pattern of tumor cells encompass areas of necrosis and hemorrhage
|
Pseudo-palisade arrangement at the periphery
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What is the prognosis of glioblastoma multiforme
|
Very poor, usually death within 1 year
|
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What is an oligodendrocyte
|
A neuroglial cell, whose surface membrane coils around neuronal axons to form the myelin sheath in white matter
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How fast does oligodendroglioma proliferate
|
Very slowly
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What age group is most commonly affected by oligodendroglioma
|
Middle age
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What is the most common site of origin of oligodendroglioma
|
Cerebral hemispheres
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Describe the typical morphology of oligodendroglioma
|
Large round nuclei surrounded by a halo of clear cytoplasm, often called “fried egg appearance”
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What is seen as typical morphology on oligodendroglioma
|
Foci of calcification
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Where is the most common location of ependymoma
|
Fourth ventricle
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What is the peak age group of ependymoma
|
Children and adolescents, but any age group can be affected
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What may result from ependymoma growth
|
Hydrocephalus due to obstructed CSF flow
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What is the pattern of the histology of ependymoma
|
Rosettes with cells encircling vessels, or tubules with cells pointing toward a ventral lumen
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What is the proliferating cell type in a meningioma
|
Arachnoid cell
|
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|
Characterize meningiomas
|
Commonly benign and slow growing
|
None
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What is the second most common primary intracranial neoplasm
|
Meningioma
|
|
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Why is surgery a feasible option with a meningioma
|
Meningioma is external to the brain, and thus can be surgically removed
|
|
|
Name common locations of meningioma
|
Convexities of the cerebral hemispheres
The parasagittal region Falx cerebri Sphenoid ridge Olfactory area Suprasellar region |
None
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What is the gross appeareance of meningioma
|
Firm, rubbery tumors, white or reddish colored, clearly distinguished from brain parenchyma
|
|
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What is the appearance of a meningioma under the microscope
|
Whorled pattern spindle cells
Ovoid nuclei Intranuclear vacuoles Calcified psammoma bodies |
None
|
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What are psammoma bodies
|
Microscopic concentric laminated mass of calcified material
|
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What is the age group most commonly affected by medulloblastoma
|
Young children under 14 years of age
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Is medulloblastoma benign or malignant
|
Highly malignant
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What area of the brain is usually involved in medulloblastoma
|
Cerebellum
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What is the gross pathology of medulloblastoma
|
Reddish gray, granular mass arising from roof of 4th ventricle
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What is the histology of medulloblastoma
|
Rosette-patterned sheets of closely packed cells with little cytoplasm and a pseudorosette pattern
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What is meant by a pseudorosette
|
Perivascular arrangement of tumor cells
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What does PNET stand for
|
Primitive neuroectodermal tumor. Medulloblastoma is one of the small cell tumors of the nervous system
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What is the prognosis of medulloblastoma
|
Poor; survival of 1-2 years after onset of symptoms is typical
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What is the age group most commonly affected by retinoblastoma
|
Young children
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What percentage of cases of retinoblastoma results from sporadic mutation
|
Approximately 60%
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How are 40% of retinoblastomas cases inherited
|
Familial
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What is the genetic defect in retinoblastoma
|
Homozygous deletion of retinoblastoma gene (chromosome 13)
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Is an attenuated form of retinoblastoma present if only one deletion exists
|
No; both deletions are required for tumor to develop
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What is hemangioblastoma
|
Tumor of blood vessel origin
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What area of the brain is most frequently affected by hemangioblastoma
|
Cerebellum
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What are common clinical complaints of hemangioblastoma
|
Difficulty with balance and walking
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What disease is associated with hemangioblastoma
|
von Hippel-Lindau disease, with similar lesions in retina and other organs
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What are 3 neoplasms associated with von Hippel-Lindau disease
|
Hemangioblastoma
Renal cell carcinoma Pheochromocytoma |
None
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What protein is sometimes produced by neoplastic hemangioblastoma cells
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Erythropoietin
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What can result from release of erythropoietin from hemangioblastoma cells
|
Secondary Polycythemia
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What is the microscopic pathology of hemangioblastoma
|
Variable presentation, from purely vascular to highly cellular, with large polygonal cells full of lipids
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What are two other names for schwannoma
|
Neurilemoma, acoustic neuroma (if localized to CN VIII)
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What is the cell of origin in a schwannoma
|
Schwann cell
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Are schwannomas benign or malignant
|
Benign
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How fast do schwannomas proliferated
|
They are slow growing, encapsulated tumors
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Where are schwannomas commonly located
|
Posterior nerve roots and peripheral nerves
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What are 2 patterns of histology seen with schwannomas
|
Antoni type A neurilemoma: elongated cells with palisade nuclei, grouped in bundles
Antoni type B neurilemoma: less cellularity, similar pattern |
None
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What disease is associated with multiple neurofibromas
|
von Recklinghausen disease
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From what cell are neurofibromas derived
|
Schwann cells, involving peripheral nerves
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What are the 6 most common primary sites of malignancy that metastasize to the brain
|
Lung; Breast (usually dura and skull); Skin; Kidney; GI tract; Thyroid
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How do most malignancies metastasize to the brain
|
Usually metastasis to the brain is hematogenous, but direct invasion is also possible
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From what tissues is a craniopharyngioma derived
|
The hypophyseal trunk or Rathke pouch
|
None
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What is a Rathke pouch
|
Diverticulum from the embryonic buccal cavity, from which the anterior lobe of the pituitary develops
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What age group is most commonly affected by craniopharyngioma
|
Children, averaging between 4-16 years old
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What clinical signs are evident with craniopharyngioma
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Visual complaints, hypothalamic syndromes
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What is the gross appearance of a craniopharyngioma
|
Calcified, multiloculated mass of several centimeters, sometimes encapsulated by the surrounding brain, with cystic areas
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What is seen on skull radiograph of a craniopharyngioma that can suggest the diagnosis
|
Plain films of the head will show characteristic calcifications
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What conditions increase the risk of developing primary lymphoma of the brain
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Conditions that cause patients to be Immunocompromised (eg AIDS, status post transplant)
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What is the most common primary brain neoplasm of Immunocompromised patients
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Lymphoma
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In the absence of immune deficiency, in what age group do primary lymphomas most commonly occur
|
Patients in their 60s or 70s
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What are 3 clinical features of lymphoma of the brain
|
Headache
Seizures Deficiency of higher neural function such as problems with memory |
None
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What is the gross pathology of lymphoma of the brain
|
Usually multifocal, seen most often in the cerebrum, arising in the perivascular spaces
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What is the microscopic appearance of lymphoma of the brain
|
Similar to the classic forms of lymphoma
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What are 2 characteristics of demyelinating diseases
|
Destruction of myelin
Preservation of axons |
None
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Which in primarily affected in demyelinating diseases, white or gray matter
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White matter
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Which is the most common of the demyelinating diseases
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Multiple sclerosis
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What are three common examples of demyelinating diseases
|
Multiple sclerosis
Acute disseminated encephalomyelitis Guillain-Barre’ syndrome |
None
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What is the age group of peak incidence of MS
|
20-30 years old
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What is the etiology of MS
|
Unknown; immune or viral theory postulated but not proven. It is thought to be multifactorial
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Is MS more common in men or women
|
Slightly more common in women
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What evidence supports the theory of an immune system etiology in MS
|
Increased incidence associated with HLA A3, B7, DR2, and DW2
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What is increased in the CSF in patients with MS and how is it detected
|
Immunoglobulin, seen as multiple oligoclonal bands on electrophoresis
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What is the relationship of incidence of MS to geographic location
|
Incidence is directly proportional to distance from the equator
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What are the morphologic changes of MS in the brain and spinal cord
|
Multiple focal areas of demyelination known as plaques
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None
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What is the microscopic appearance of areas of demyelination in MS
|
Localized edema, congestion, and microglial proliferation
Progressive astrocytosis and infiltration Eventually, sclerotic plaque and reactive gliosis |
None
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What 3 sites are particularly affected in MS
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Optic nerve
Brainstem Paraventricular areas |
None
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What cells infiltrate MS plaques before reactive gliosis occurs
|
Helper CD4+ cells
Cytotoxic CD8+ T lymphocytes Macrophages |
None
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What are the early clinical findings of MS
|
Motor deficits of the distal lower extremities, visual disturbances and retrobulbar pain, sensory deficits, and sometimes bladder incontinence
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What is the classic Charcot triad of MS symptoms
|
Nystagmus
Intention tremor Scanning speech |
None
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What is the characteristic pattern of MS
|
Periods of exacerbation alternate with long periods of asymptomatic remission, but there is eventual progression to invalidism and mental deterioration
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What is another name for acute disseminated encephalomyelitis
|
Postinfectious encephalitis
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Name 4 viral illnesses that can cause acute disseminated encephalomyelitis
|
Measles; Mumps; Rubella; Chicken pox
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What are the pathologic findings of acute disseminated encephalomyelitis
|
Widespread demyelination
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What is the most likely etiology of widespread demyelination in acute disseminated encephalomyelitis
|
Delayed hypersensitivity reaction to viral pathogens
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What is the prognosis of acute disseminated encephalomyelitis
|
Variable; ranges from complete recovery to death
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None
|
|
What is Guillain-Barre’ syndrome
|
Acute inflammatory demyelinating disease; usually occurs following a viral infection, immunization, or allergic reaction; probably of autoimmune etiology
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What is primarily involved with Guillain-Barre’ syndrome
|
Peripheral nerves
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|
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What age group has the peak incidence of Guillain-Barre’ syndrome
|
Young adults
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What are the clinical features of Guillan-Barre’ syndrome
|
Ascending muscle weakness and paralysis beginning in the distal lower extremities and progressing proximally
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Can Guillain-Barre’ be fatal
|
Yes, rarely expiratory muscles can be paralyzed, causing respiratory failure and death
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|
What can be seen in the CSF in Guillain-Barre’ syndrome
|
Albumino-cytologic dissociation of CSF; can be an important diagnostic finding
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|
What is albumino-cytologic dissociation
|
Greatly increased protein, with only small increase of cell count
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|
What is meant by degenerative disease
|
One that causes slowly progressive loss of neural function, can occur in CNS as well as PNS
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|
List 4 causes of degenerative disease in the nervous system
|
Dementia
Huntinton disease Parkinsonism Amyotrophic lateral sclerosis |
None
|
|
What is dementia
|
Organic disease of the CNS causing progressive loss of intellectual capabilities
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|
What is the most common cause of dementia
|
Alzheimer disease
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|
|
What is the 2nd most common cause of dementia
|
Multi-infarct dementia
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|
|
What are some less common disorders than may cause dementia
|
Chronic alcoholism; Binswanger disease; Pick disease
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|
|
What are the defining characteristics of Alzheimer dementia
|
Multiple cognitive defects manifested as memory impairment and other possible disturbances in speech, language, recognition, and executive function. There is gradual onset and continuing cognitive disease. These symptoms must not be the result of another disease that could affect the nervous system in this way
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|
Approximately how many American are affected with Alzheimer dementia
|
Over 2 million; the number is growing as the overall population ages
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|
|
What are 2 clinical findings of Alzheimer dementia
|
Slow, progressive loss of intellect; Deterioration of motor function, including contractures and paralysis
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|
|
What can be the early sign of declining intellect
|
Short-term memory loss
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|
|
What can develop from Alzheimer dementia
|
Long-term memory loss, eventually leading to inability to read, count, or speak
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|
|
What are 5 characteristic morphologic abnormalities in Alzheimer dementia
|
Neurofibrillary tangles
Senile plaques Granulovacuolar degeneration Hirano bodies Generalized cerebral atrophy |
None
|
|
What are neurofibrillary tangles
|
Intracytoplasmic bundles of filaments, derived from microtubules and neurofilaments
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|
|
Where are neurofibrillary tangles found in the brain
|
Within neurons, in the cerebral cortex
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|
|
What are senile plaques
|
Also known as neuritic plaques; swollen nerve processes forming spherical foci with a central amyloid protein core
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|
|
Where are senile plaques commonly located
|
Cerebral cortex
Amygdala Hippocampus |
None
|
|
What is granulovacuolar degeneration
|
Intraneuronal cytoplasmic vacuoles containing granules
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|
|
Where are granulovacuolar vacuoles characteristically located
|
Pyramidal cells of the hippocampus
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|
|
What are Hirano bodies
|
Intracytoplasmic eosinophilic inclusions seen in the proximal dendritic processes
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|
|
In Alzheimer dementia, cerebral atrophy is seen most prominently in which areas of the brain
|
Frontal and hippocampal areas
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|
|
What is the gross appearance of Alzheimer dementia
|
Sulci look widened because of loss of neurons and subsequent narrow gyri
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|
|
What syndrome can exhibit similar findings to Alzheimer dementia
|
Down syndrome in patients who survive to 40 years of age or older
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|
|
In what two diseases can neurofibrillary tangles be seen
|
Alzheimer dementia and Parkinson disease
|
|
|
What is the etiology of Alzheimer disease
|
Unknown
|
|
|
What are 3 possible mechanisms that have been theorized as the cause of Alzheimer dementia
|
Choline acetyltranferase deficiency
Alterations in nucleus basalis of Meynert Abnormal amyloid gene expression |
None
|
|
What is the tau protein
|
Normally synthesized in gray matter, it has been shown to have hyperphosphorylation and it accumulates in the tangles and plaques of patients with Alzheimer disease
|
|
|
What is Binswanger disease
|
Multiple lacunar infarcts and progressive demyelination of subcortical area. Also known as subcortical leukoencephalopathy
|
|
|
What disease process is associated with Binswanger disease
|
Hypertension
|
|
|
What area of the brain is characteristically spared in Binswanger disease
|
Cortex
|
|
|
What is the clinical presentation of Pick disease
|
Similar to Alzheimer disease
|
|
|
What is the etiology of Pick disease
|
Unknown
|
|
|
What are 3 characteristic pathologic features of Pick disease
|
Marked cortical atrophy
Edematous neurons Pick bodies (round intracytoplasmic inclusion bodies, composed of neurofilaments) |
None
|
|
What two lobes of the brain are markedly atrophied in Pick disease
|
Temporal and frontal lobes
|
|
|
What is Huntington disease
|
Progressive degeneration and atrophy of frontal cortex, caudate nucleus, and putamen, also referred to as Huntington chorea
|
|
|
What neurons are especially affected in Huntington disease
|
Cholinergic and GABA-ergic neurons
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|
|
In the genome, what characterizes a worse prognosis for Huntington disease
|
Increased numbers of tri-nucleotide repeats
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|
|
At what age will clinical abnormalities associated with Huntington disease commonly start
|
30-40 years of age; fatal prognosis usually by 55-60 years of age
|
|
|
What are the earliest seen features of Huntington disease
|
Athetoid movements (characteristic involuntary, continuous, slow writhing movements, typically severe in the hands and arms)
|
|
|
What is Parkinsonism and what are the associated clinical features
|
A group of disorders characterized by:
Resting pill-rolling tremor Masked facies Shuffling gait Muscular rigidity Slowed movements |
None
|
|
What is the most common cause of parkinsonism
|
Idiopathic Parkinson disease (also known as paralysis agitans)
|
|
|
What are other causes of parkinsonism
|
Von Economo encephalitis, trauma, drugs and toxins, and Shy-Dragner syndrome
|
|
|
What is von Economa encephalitis
|
Infectious disease seen in 1915-1918, associated with the influenza pandemic; it causes postencephalitic parkinsonism in people 85 years of age or older who where affected by that pandemic
|
|
|
Participation in what sport can cause parkinsonism
|
Boxing, because of repeated trauma to the head
|
|
|
What contaminant in illicit street drugs causes a picture similar to parkinsonism
|
MPTP, methyl-phenyl-tetrahydropyridine, a dopamine antagonist
|
|
|
What is the Shy-Drager syndrome
|
Autonomic dysfunction and associated orthostatic hypotension with parkinsonism
|
|
|
By what age will clinical symptoms be evident in Parkinson disease
|
Usually after 50 years of age
|
|
|
What is the histology of Parkinson disease
|
Granual loss and depigmentation of cells in the substantia nigra and locus ceruleus
|
|
|
What do the damaged cells in Parkinson disease characteristically contain
|
Lewy bodies, eosinophilic intracytoplasmic inclusions
|
|
|
What neurotransmitter is depleted in the corpus striatum in Parkinson disease
|
Dopamine, because damaged cells in the substantia nigra inhibit neuronal pathways from the substantia nigra to the corpus striatum
|
|
|
What therapy can be effective in Parkinson disease
|
L-dopa, a dopamine precursor
|
|
|
What is the most common form of motor neuron disease
|
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig disease
|
|
|
Which motor neurons are degenerating in ALS
|
Both upper and lower motor neurons of the lateral corticospinal tracts and anterior motor neurons of the cord
|
|
|
What happens to the muscles in ALS
|
Muscles atrophy from denervation
|
|
|
What is the clinical presentation of ALS
|
Both upper and lower motor neuron signs are present
|
|
|
List the upper motor neuron signs that signify ALS
|
Hyperreflexia
Spasticity Pathologic reflexes (eg Babinski reflex) |
None
|
|
List the lower motor neuron signs that signify ALS
|
Atrophy of muscles
Fasciculations |
None
|
|
Which muscles are commonly involved with ALS at first presentation
|
Intrinsic muscles of the hand, and muscles of the arm and shoulder
|
|
|
How quickly does ALS progress
|
Rapidly, with death coming in 1-6 years
|
|
|
What is pernicious anemia
|
Megaloblastic anemia and neurologic disorder, resulting from vitamin B12 deficiency
|
|
|
What is the neurologic disease of pernicious anemia
|
Subacute combined degeneration of the spinal cord
|
|
|
What part of the spinal cord is involved in pernicious anemia
|
The posterior and lateral columns
|
|
|
What is the gross pathologic appearance of the spinal columns in pernicious anemia
|
Gray discoloration of the dorsolateral columns
|
|
|
What is Wernicke syndrome
|
Mental deficits characterized by memory loss, confabulation, and loss of location sense
|
|
|
What is the predisposing factor for development of Wernicke syndrome
|
Chronic alcoholism
|
|
|
What is the gross pathology of Wernicke syndrome
|
Marked congestion of periventricular gray matter, with many petechial hemorrhages
|
|
|
What is the microscopic histology of Wernicke syndrome
|
Prominent capillaries, from endothelial hypertrophy and hyperplasia, and acute ischemic necrosis of associated neurons
|
|
|
What is acute Wernicke encephalopathy and what causes it
|
Rapid development of encephalopathy, characterized by severe ataxia, mental confusion, delirium, and restlessness. It results from thiamine deficiency
|
|
|
What can precipitate an acute Wernicke encephalopathy
|
Administration of IV glucose load prior to administration of thiamine during inpatient treatment (ie must give thiamine before glucose)
|
|
|
What are the pathologic features of Wernicke encephalopathy
|
Inflammatory hemorrhagic lesions in the hypothalamus, mamillary bodies, periaqueductal and periventricular regions
|
|
|
What is myasthenia gravis
|
A common disorder, affecting more women than men, usually caused by autoimmune processes
|
|
|
What is the diagnostic finding in most patients with myasthenia gravis
|
Antibodies against the neuromuscular acetylcholine receptors
|
|
|
What is the clinical presentation of myasthenia gravis
|
Muscles, such as extraocular muscles, are easily fatigues and demonstrably weak, with some relief if rested
|
|
|
What is the characteristic finding in the muscle in myasthenia gravis
|
Lymphocytic infiltrates around the degenerating fibers
|
|
|
What do EMG studies of patients with myasthenia gravis show
|
Decremental responses to repeated nerve stimulation
|
|
|
What is the prognosis of myasthenia gravis
|
Death, usually from respiratory infection, predisposed by weak muscles of respiration
|
|