CNS infections Flashcards
meningitis is inflammation of which meningeal layers?
arachnoid and pia
classic triad for meningitis?
- fever
- headache
- nuchal rigidity
what is kernig sign?
resistance to passive extension at the knee
what is brudzinksi sign?
spontaneous flexion of the knees and hips when neck is passively flexed
what is the most common pathogen causing meningitis in people over 18?
s. pneumo
when does imaging precede LP for meningitis diagnosis?
- new onset sz
- immunocompromised state
- focal findings
- decreased level of consciousness
what is the normal value for CSF pressure?
60-180
which WBC predominates in LP for meningitis?
neutrophils
what is the treatment for bacterial meningitis? why?
- steroids
- critical event in pathogenesis of CNS complications is inflammatory reaction
what is seen in CSF for viral meningitis?
- pleocytosis (lymphocytic vs PMNs)
- hypoglycorrachia
- mild protein elevation
what is the most common viral pathogen causing viral meningitis?
enterovirus
what is the clinical presentation of HSV encephalitis?
- global: fever, headache, change in LOC
- focal: bizarre behavior, aphasia, seizure, hemiparesis
how is diagnosis made for HSV encephalitis?
attempt to localize to temporal lobe with MRI or EEG
what are the CSF findings in HSV encephalitis?
- WBC: 5-500 lymphs
- frequently hemorrhagic
- mild increased protein
- decreased glucose
- acute duration (under 4 weeks)
- mild-moderate monopleocytosis, nl glucose, mild inc in protein
viral
- acute duration (under 4 weeks)
- significant PMN pleocytosis, low glucose, high protein
bacterial
- chronic course (over 4 weeks)
- moderate monopleocytosis, low glucose, high protein
fungal, mycobacterial, noninfectious
what are the noninfectious causes of chronic meningitis?
- neoplastic
- sarcoid
- vasculitis
- chemical meningitis
how does meningitis from TB spread?
discharge from bacilli from tubercles within brain or meninges into subarachnoid space
- thick, gelatinous exudate produces basal meningitis placing CNs at risk
what are the clinical symptoms of TB meningitis?
- headache, fever, meningismus, menal status changes
- cranial neuropathies
- hemiparesis
what is used to treat progressive multifocal leukoencephalopathy?
natalizumab
what is the pathophysiology of PML?
reactivation of endemic JC papovavirus
what are the clinical symptoms of PML?
- insidious progression of dementia with focal findings
- behavioral, cognitive, and speech impairment
- hemiparesis, visual field defects
how is diagnosis of PML made (tests / findings)?
- MRI: nonenhancing multifocal white matter lesions
- CSF: protein elevation, PCR for JC virus
