CNS- trauma and demyelinating disorders Flashcards
how does a epidural hematoma look on CT?
lens shaped lesion
what type of hematoma can present with a lucid interval period
epidural hematoma
what causes a subdural hematoma?
tearing of bridging veins that lie between the dura and arachnoid (usually due to trauma)
how does a subdural hematoma present on CT?
crescent shaped leasion
what can result from a tonsillar herniation?
compression of brain stem leading to cardiopulmonary arrest
what can result from uncal herniation?
- compression of cr. n3 leading to eye moving down & out
- compression of posterior cerebral artery leads to infarct of occipital lobe (contralateral homonyous hemianopsia)
- rupture of the paramedian artery leads to duret (brainstem) hemorrhage
what cells myelinate the CNS
oligodendrocytes
what cells myelinate the PNS
schwann cells
what is metachromatic leukodystrophy due to?
deficiency of arylsulfatase enzyme (sulfatides will be unable to degrade the myelin)
what causes krabbe disease?
deficiency of galactocerebrosidase (auto recessive) and galactocerebroside will accumulate in macrophages
what is adrenoleukodystrophy due to?
impaired addition of coenzyme A to long chain fatty acids (X linked)
what HLA is MS associated with? what envirnmental factor is associated with MS
HLA-DR2
living away from the equator
what will the lumbar puncture show in ppl that have MS
increased lymphocytes, increased immunoglobins with oligoclonal IgG bands
what causes subacute sclerosing panencephalitis?
persistent infection of the brain by the measles virus
what causes progressive multifocal leukoencephalopathy?
JC virus infection of oligodendrocytes (white matter) + immunosuppresion
