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55 Cards in this Set
- Front
- Back
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Which parts of the brain are most susceptible to ischemia?
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Purkinje's cells
hippocampal neurons |
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Which parts of the brain are most susceptible to herpes?
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Temporal lobe
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Which parts of the brain are most susceptible to ALS?
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motor neurons
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Which parts of the brain are most susceptible to histologic reactions?
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Any part!
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Examples of secondary space occupying lesions in the CNS?
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cerebral edema
hydrocephalus |
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What is the definition and symptoms of increased intracranial pressure?
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CSF > 200 mmH2O lying down
h/a, confusion, obtundation (decreased mental capacity), papilledema |
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What are the most serious consequences of increased cranial pressure?
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Brain stem compression
Hemorrhage |
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What part of the brain is herniated with subfalcine? transtentorial? coning?
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Subfalcine = cingulate gyrus
Transtentorial = medial temporal lobe Coning = cerebellar tonsils |
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What are duret hemorrhages?
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Compression of the vessels during herniation that leads to leakage of blood from the capillaries and infarction
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What are the pathogenic types of cerebral edema?
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cytotoxic
vascular |
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What are the causes of cytotoxic cerebral edema?
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(Intracellular cause)
Ischemia Water intoxication |
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What are the causes of vasogenic cerebral edema?
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(extracellular cause - inflammation ->cytokine release)
Capillary leakage from tumor Abcess, trauma, or hemorrhage |
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What is hydrocephalus?
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The distention of ventricles due to an increase in csf volume (due to increased production or decreased absorption)
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Trace the flow of CSF from productions to absorption.
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Made in the choroid plexus of the ventricles and then exits the ventricles via the formina of Luschka and Magendie. Absorbed by arachnoid villi
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What's noncommunicating hydorcephalus?
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Obstructive/internal - blockage within the cerebrum
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What's communicating hydorcephalus?
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external - blockage outside the cerebrum (at arachnoid villi)
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What do you see in young kids/infants with hydrocephalus?
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They get big heads!
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What are the signs of acute increased intracranial pressure in adults? What about chronic?
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Acute = drowsiness, decreased consciousness, pupillary changes
Chronic = dementia, gait disturbances, incontinence |
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What's hydrocephalus ex vacuo?
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Compensatory enlargement of the ventricles due to cerebral atrophy (seen with Picks/Alzheimers)
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Causes of obstructive hydrocephalus? (6)
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Stenosis of the Aqueduct of Sylvius
Dandy Walker Syndrome Arnold-Chiari malformation Vascular malformation Inflammatory processes Neoplasms |
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Causes of communicating hydrocephalus? (4)
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Choroid plexus adenoma
Deficient absorption of CSF: post infection posthemorrhage dural sinus thrombosis |
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What are the ways you can get a CNS infection?
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Hematogenous spread
Direct implantation Local extention |
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What are the common agents seen with pyogenic meningitis of the neonate?
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E. coli, group B Streptococcus, Listeria monocytogenes
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What are the common agents seen with pyogenic meningitis in infants and kids?
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Haemophilus influenzae
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What are the common agents seen with pyogenic meningitis in teens?
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Neisseria meningitidis (epidemic)
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What are the common agents seen with pyogenic meningitis in adults?
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Streptococcus pneumonia, gram negatives (sporatic)
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What are the classic clinical findings seen with pyogenic meningitis? (4 main, 4 additional)
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Fever, Headache
Meningeal irritation (nuchal rigidity, + Kernig/Brudzinski's) Clouding of consciousness Also: photophobia (irritation around optic nerve), n/v, seizures |
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What's Kernig's sign?
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Pt can't straighten leg (extend knee) if thigh's flexed to 90 degrees
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What's Brudzinski’s sign?
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Pt that's laying flat automatically flexes their knees and hips when the doc lifts their head (passively flexes their neck)
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What do you see in the CSF of a pt with bacterial meningitis?
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Turbid fluid, increased pressure
Elevated WBC with PMNs Elevated protein (>40 mg%) Decreased glucose (<2/3 blood level) Positive gram stains/cultures |
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What's the prognosis of pyogenic meningitis?
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Mostly fatal untreated.
Surviors = adhesive arachnoiditis (scarring in the arachnoid villi) with hydrocephalus |
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How does viral meningitis differ from pyogenic? (3 main ways)
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1. Findings similar but often less severe with other "flu-like" sxs
2. CSF = not as turbid, more lymphocytes (except first 24 hrs), nl glucose, moderate protein elevation. 3. Typically self-limiting |
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What are the three categories of complications from neurosyphilis (tertiary syphilis)?
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Meningitic
Paretic Tabes dorsalis |
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What do you see with meningitic neurosyphilis?
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spirochete invasion = inflamm of vessels and meninges that goes on for weeks = signs and sx of chronic meningitis + Endarteritis obliterans (intimal proliferation of the meningeal vessels)
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What do you see with Paretic neurosyphilis?
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Spirochetes invade the parenchyma = cerebral atrophy and cortical neuronal loss with gliosis = dementia with bizarre behavior/ideations
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What do you see with Tabes dorsalis neurosyphilis?
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Effects sensory nerves and dorsal roots = decreased proprioception (walk like zombies), charcot joints (arthritis), no DTRs, and Argyll Robertson pupils (non-reactive but accommodating).
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What's viral encephalitis? Causative bug?
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Diffuse viral infection of the brain
Normally due to arboviruses |
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Clinical signs of viral encephalitis?
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seizures, lethargy, coma, delirium, headaches
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CSF seen with viral encephalitis?
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increased lymphocytes, elevated protein, glucose normal
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What's the difference between neonatal and adult herpes encephalitis?
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Neonatal's have diffuse cerebral involvement whereas adults only have involvement of the temporal lobes (where the herpes receptors are)
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What's the long term sequelae of herpes encephalitis in the adult?
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Dementia and memory loss
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What cases rabies?
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Rhabdovirus from an animal bite that ascends the peripheral nerves.
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What's the CNS effect of rabies?
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Meningeal encephalitis
Neuronal necrosis of the midbrain, medulla, and basal nuclei |
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Clinical presentation of rabies?
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Icubates 1-3 months then = fever, flaccid paralysis, mania, stupor, CNS irritability, and wound paresthesias. (then you die!)
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What does rabies in CNS look like grossly?
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Edema and congestion
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What's the microscopic appearance of rabies in the CNS?
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neuronal degeneration and diffuse inflammation (worse in midbrain and floor of fourth ventricle) with Negri bodies (eosinophilic inclusions seen in hippocampal neurons and Purkinje cells)
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What are infectious prions (generallly)?
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Modified forms of normal proteins found in mammalian nervous systems (no genetic material, bio function unknown)
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What's the structure of infectious prions (sPrp)?
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contains 2 types of polypeptide chains: original alpha form with more altered beta forms
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What's the structure of normal prions (cPrp)?
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More alpha than beta - not infectious, found in all mammalian brains
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What happens when sPrp's get into the brain?
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They contact the normal prions and start a chain reaction to turn them into the infectious kind which then accumulate in neuronal vesicles until they burst and spread further = brain's vacuolated (spongiform)
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What are the different types of prion diseases in animals? (4)
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Bovine spongiform encephalopathy
Sheep and goat scrapie Chronic wasting disease in North American elk and deer Transmissible mink encephalopathy |
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What are the names of the human prion diseases? (4)
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Sporadic Creutzfeldt-Jacob
Iatrogenic CJD (corneal transplants) Kuru New Variant CJD (mad cow) |
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What's the difference between sporadic and new variant CJD?
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New variant effects younger people (sporadic affects elderly) and has more psych symptoms.
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What are the hereditary types of spongiform encephalopathies?
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Gerstmann-Straussler-Schienker
Familial CJD (only 5-10% of CJD cases) Fatal familial insomnia |
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What are the different HIV infections of the nervous system? (4)
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Acute aseptic meningitis
Subacute encephalitis Vacuolar encephalitis Peripheral neuropathy |
