Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

83 Cards in this Set

  • Front
  • Back
By definition, what is the difference between hypoxia and ischemia?
• Hypoxia is a deprivation of oxygen with maintained blood flow • Ischemia is greatly reduced or interrupted blood flow
What are the 2 general types of ischemia?
• Focal ischemia ( ex. stroke) where collateral circulation can provide blood to uninvolved areas • Global ischemia (ex. cardiac arrest) where no collateral circulation exists
Name and describe the 2 types patterns of global ischemia injury
• Watershed infarcts are located in overlapping areas supplied by the major cerebral vessels (ACA, MCA, PCA) • Laminar necrosis occurs in areas suppled by the penetrating arteries derived from the Pia Mater
What is the principal excitatory neurotansmitter in the brain?
Explain how excess glutamate can contribute to cell injury
• Glutamate, when bound to a particular receptor (NMDA), causes opening of calcium channels • Open calcium channels leads to a series of calcium-mediated processes called the calcium cascade • Activation of the calcium cascade leads to release of intracellular enzymes that cause cell death
How can an increased intercranial pressure (ICP) cause brain injury?
Excessive ICP can: • obstruct cerebral blood flow • destroy brain cells • displace brain tissue as in herniation • damage delicate brain structures
What are the 3 parts that contribute to intracranial volume?
• blood (10%) • brain tissue (80%) • CSF (10%)
What is the Monro-Kellie hypothesis?
small increases in the volume of one component can be compensated for by a decrease in the volume of either one or both of the other two compartments
What is one of the earliest and most reliable signs of increased ICP?
• a decrease in LOC • can deteriorate from alertness to confusion, lethargy, obtundation, stupor, and coma
What is the Cushing reflex?
• a late reflex see with a marked increase in ICP • triggered by ischemia of the vasomotor center in the brain stem • characterized by 3 signs: 1) marked increase in mean arterial BP (270 mm Hg) 2) widened pulse pressure 3) slowing of heart rate
What is the falx cerebri?
a septum that divides the two hemispheres
What are the 2 broad catergories of brain herniations?
supratentorial and infratentorial
What is cerebral edema?
• brain swelling • an increase in tissue volume secondary to abnormal fluid accumulation
Name the 2 types of cerebral edema
• Vasogenic edema • Cytotoxic edema
Describe vasogenic edema
• occurs from an impaired function of the blood-brain barrier • water and protein are transferred from the vasculature to the interstitial space • manifests as focal neurologic deficits, disturbances in consciousness, & severe intracranial hypertension
Describe cytotoxic edema
• involves the actual swelling of brain cells due to increased intracellular fluid • can be caused by hypoosmotic states, impairment of Na+/K+ pump
What is Hydrocephalus?
an abnormal increase in CSF volume in any part of the ventricular system that causes enlargment of the CSF compartment
What are the 2 causes of hydrocephalus?
• decreased absorption of CSF • overproduction of CSF
Name the 2 types of hydrocephalus
• Noncommunicating • Communicating
Describe noncommunicating hydrocephalus
• occurs when an obstruction in the ventricular system prevents teh CSF from reaching the arachnoid villi • can be caused by congenital malformation, tumors, inflammation, or hemmorhage
Describe communicating hydrocephalus
• results from impaired reabsorption of CSF from the arachnoid villi into the venous system
What are pathologic patterns that occur with hydrocephalus?
• enlarged cerebral hemispheres • dilated ventricular system • gyri on brain surface becomes less prominent • reduced volume of white matter
Which type of hydrocephalus is more likely to manifest with increased ICP, acute-onset or slowly developing hydrocephalus?
Acute onset
What are symptoms of acute-onset hydrocephalus?
symptoms of increased ICP such as headache, vomiting, papilledema, or lateral rectus palsy
What are the 2 categories of traumatic head injuries?
• Primary (or direct) injuries: damage is caused by impact • Secondary injuries: samge results from subsequent brain swelling, infection, or cerebral hypoxia
What is the most common cause of secondary brain injury?
What is the definition of a concussion?
a momentary interruption of brain function with or without LOC
What is the most common cause of a epidural hematoma?
• usually caused by a skull fracture • usually results from a tear in an artery, most often the middle menigeal
What is the typical presentation of a persion with an epidural hematoma?
• presents with a history of head injury and brief period of LOC, followed by a lucid period, followed by rapid progression to unconsciousness • if untreated, progressed to increased ICP, tentorial herniation, and death
What is the usual cause of a subdural hematoma?
a tear in the small bridging veins that connect veins on the surface of the cortex to dural sinuses
What are key clinical signs from injury to the diencephalon?
• impaired consciousness • small reactive pupils • intact oculocephalic reflex • decorticate posturing • Cheyne-Stokes respirations
What are key clinical signs of injury to the midbrain?
• coma • fixed, midsize pupils • impaired oculocephalic reflex • neurogenic hyperventilation • decerebrate posturing
What are key clinical signs of injury to the pons?
• coma • fixed, irregular pupils • dysconjugate gaze • impaired cold caolric stimulation • loss of corneal reflex • hemi/quadriparesis • decerebrate posturing • apneustic respirations
What are key clinical signs of injury to the medulla?
• coma • fixed pupils • flaccidity • loss of gag and cough reflexes • ataxic/apneic respirations
What is consciousness?
• the state of awareness of self and the environment and of being able to become oriented to new stimuli • two components: 1) arousal and wakefulness 2) content and cognition • requires the concurrent functioning of both cerebal hemispheres and reticular activating system
Where is the reticular formation located?
• it extends from the medulla through the pons to the midbrain
What is the oculocephalic reflex?
aka doll's-head eye movement
What is the oculovestibular test?
• aka cold caloric test • cold water is instilled in the ear to elicit nystagmus
Decorticate posturing indicates a lesion in what area?
the cerebral hemisphere or internal capsule
Decerebrate posture occurs from lesions in this area
lesions in the diencephalon that extend to the midbrain and upper brain stem
What are 3 metabolic factors that affect cerebral blood flow?
carbon dioxide, hydrogen ion, and oxygen concentration
What are some causes of hemorrhagic stroke?
blood vessel rupture due to: • hypertension • aneurysms • AV malformations • head injury
What are the 5 stroke subtypes and their frequency?
• large artery atheroscelerotic disease (20%) • small vessel or penetrating artery disease (lacunar stroke) (25%) • cardiogenic embolism (20%) • cryptogenic stroke (ie. undetermined cause) (30%) • other, unusual causes (5%)
What is a penumbra?
• an ischemic band or area of minimally perfused cells that surrounds a centro core of dead or dying cells • occurs during the evolution of a stroke
What are common sites of plaque formation which can cause ischemic strokes?
larger vessels of the brain including: • the origins of the internal carotid and vertebral arteries • junctions of the basilar and vertebral arteries
Describe a small vessel stroke (lacunar infarct)
• small infarcts located in the deepe, noncortical parts of the brain or brain stem • found in single deep penetrating arteries supplying the internal capsule, basal ganglia, or brain stem • during healing, infarcts leave behind small cavities, or lacunae (lakes)
What are the six basic causes of lacunar infarcts?
• embolism • hypertension • small vessel occlusive disease • hematologic abnormalities • small intracerebral hemorrhages • vasospasm
What causes an embolic stroke?
a moving blood clot that travels from its origin to the brain
What is the most frequent site of embolic strokes?
middle cerebral artery
What are some cardiac conditions that predispose to formation of an emboli?
• rheumatic heart disease • A Fib • mobile aortic arch atheroma • recent MI • ventricular aneurysm • bacterial endocarditis • patent forman ovale (for paradoxial venous emboli in arterial system)
What are the most common predisposing factors for hemorrhagic stroke?
advancing age and hypertension
List stroke-related deficits, from most common to least common
• Motor deficits (most common) • Language • Sensation • Cognition
What are the most common cerebral aneurysm?
small saccular aneurysms called berry aneurysms
What are some manifestations of a subarachnoid hemmorhage?
• worst headache of my life • vomiting • LOC • meningeal symptoms (nuchal rigidity, photophobia) • stroke syndrome • cerebral edema and increased ICP • pituitary dysfunction • hypertension & dysrhythmias
What are complications of aneurysmal rupture?
• rebleeding & vasospasm (most serious & most difficult to treat) • hydrocephalus (due to plugging of arachnoid villi from blood) • hypothalamic dysfunction • seizure activity
What is the definitive diagnostic tool for detecting an aneurysm?
conventional catheter angiography
What are arteriovenous malformations?
• a complex tangle of abnormal arteries and veins linked by one or more fistulas • these vascular networks lack a capillary bed
What are the hemodynamic effects from AV malformations?
• venous channels are exposed to high-pressure blood flow due to the absence of capillaries (predispositions to rupture & hemorrhage • elevated venous & arterial pressures divery blood away from surrounding tissue, impairing tissue perfusion
True/False: Stoke is the number two leading cause in death in the US, behind CAD
Stroke is the third leading cause in death in the US The correct answer is: False
What are the 2 types of acute infectious meningitis?
• acute purulent meningitis (usually bacterial) • acute lymphocytic meningitis (usually viral)
What are common bacterial causes of meningitis?
• Streptococcus Pneumoniae (ie pneumococcus) (most common) • H. Flu • Neisseria meningitidis • group B streptococcus (in neonates)
Name and describe the 2 assessment test to evaluate for meningitis
• Kernig's sign is resistance to extension of the knee while the person is lying with the hip flexed at a right angle • Brudzinski's sign is elicited when flexion of the neck induces flexion of the hip and knee
How is viral meningitis different from bacterial meningitis?
• the course of illness is less severe • presence of lymphocytes in fluid instead of neutrophils • acute viral meningitis are self-limited and require only symptomatic treatment
What are some viral etiologies of viral meningitis?
• Enteroviruses (coxsackie, poliovirus, echovirus) • Epstein-Barr virus • mumps • herpes simplex virus (HSV) • West Nile virus
What is encephalitis and what usually causes it?
• Enceohalitis is a generalized infection of the parenchyma of the brain of spinal cord • usually caused by a virus (ie arbovirus, poliovirus, or rabies virus)
How is the presentation of patient with encephalitis different from a patient with meningitis?
• both are characterized by fever, headache, and nuchal rigidity • encephalitis more often presents with neurologic disturbances (lethargy, disorientation, seizrues, focal parlyisi, delirium, & coma)
What are the 3 basic types of brain tumors?
• primary intracranial tumors of neuroepithelial tissue • primary intracranial tumors that originate in the skull cavity, but not derived from brain tissue • metastatic tumors
What are the 2 main categories of glial tumors?
• astrocytic • oligdendroglial
What are the 2 sub-categories of astrocytic tumors?
• fibrillary astrocytic tumors - account for 80% of primary adult brain tumors; more common in middle age • pilocytic astrocytomas - usually occurs in children & young adults
What are characteristics of Primary CNS lymphomas?
• deep, periventricular, diffuse tumors common in immunocompromised patients • associated with Epstein-Barr virus and derived from large B cells
Name and describe the two broad categories of seizures
• Partial seizure - the seizure beings in a specific area of one cerebral hemisphere • Generalized seizure - begin simultaneously in both cerebral hemispheres
What type of siezure usually involve only one hemisphere and does not involve LOC?
Simple partial seizure
What are the different types of simple partial seizures?
Different types of simple partial seizures include those: • with motor symptoms • with sensory symptoms • with autonomic symptoms • with psychic symptoms
What is a Jacksonian seizure?
When motor movement spreads to other cortical areas with sequential involvement of body parts
What are characteristics of complex partial seizures?
• involve impairment of consciousness and often arise from the temporal lobe • often accompanied by automatisms (repetitive, nonpurposeful activity)
Describe a secondarily generalized partial seizure
focal seizure at onset but then become generalized, involving deeper structures of the brain, such as the thalamus & reticular formation
What are characteristics of generalized-onset seizures?
• most common type in young children • symptoms include unconsciousness and bilateral symmetric motor responses
What are the 4 types of generalized-onset seizures?
• Absence seizures • Atonic seizures • Myoclonic seizures • Major Motor (Grand Mal or Tonic-Clonic)
What are characteristics of Absence seizures?
• generalized, non-convulsive epileptic events expressed as disturbances in consciousness • typically occur in children • characterized as a blank, stare, motionlessness, and unresponsiveness
Describe an atonic seizure
• a sudden, split-second loss of muscle tone • causes slackening of the jaw, drooping of limbs, or falling to the ground • aka drop attachs
What are characteristics of a myoclonic seizure?
• involves brief involuntary muscle contractions caused by stimuli of cerebral origin • involves bilateral jerking of muscles, generalized or confined to the face, trunk, or one or more extremities
What is status epilepticus?
seizures that do not stop spontaneously or occur in succession without recovery