CNS infections Flashcards
subdural abscess
infection may spread to subdural space from air sinuses or middle ear
traversed by brr aa, but these will not deliver abx
must be drained
IV abx
normal CSF pressure
<200mm
normal CSF protein
14-45mg
normal CSF glucose
50% of serum
normal CSF WBCs
0-10
CSF pressure with bacterial meningitis
high»_space;200
CSF protein with bacterial meningitis
high
45-200
CSF glucose with bacterial meningitis
very low, maybe 0
CSF WBCs with bacterial meningitis
polys in 1000s
CSF pressure w/viral meningitis
normal-slightly high
CSF protein w/viral meningitis
normal-slightly high
CSF glucose w/viral meningitis
normal
CSF WBCs w/viral meningitis
monos 10-100s
most common infectious agent of CNS
leptomenigitis
common cause of bacterial meningitis in birth-2months
E.coli
Grp B strep
listeria
common cause of bacterial meningitis in 2months-5yrs
strep pneumoniae
meningococcus
H. influenza (before vaccine)
common cause of bacterial meningitis in older child/adult
Strep pneumoniae
N. meningitdis (epidemics)
common cause of bacterial meningitis in elderly
S. penumoniae
E. coli
group B strep
listeria
common viruses which cause encephalitis
arboviruses
CMV
herpes
HIV
rare viral causes of encephalitis
rabies
Progressive Multifocal Leukoencephalopathy
Subacutre Sclerosing Panencephalitis
herpes encephalitis clinical
HA, fever, stiff neck, drowsy, coma, neuro symptoms
fatal w/o rapid Tx
25-50% fatal w/Tx
long term sequel in survivors common
neonatal vs adult herpes encephalitis
adults show predilection for frontal and temporal lobes, neonatal global
rabies
variable incubation 10days-year
centripetal axonal transport to CNS
HAs, fever, malaise, dysphagia , stupor, coma, death
rabies histo
negri bodies
inclusions of proteins made by virus in cytoplasm
progressive multifocal leukoencephalopathy (PML)
- caused by polyomavirus (JC and BK)
- latent in kidneys and B-cells in tonsils of most adults and sometimes the brain
- reactivation w/in CNS or in peripheral tissues -> white matter damage
- infects/destroys oligodendrocytes
PML clinical
- infection in humans in generally asymptomatic
- focal neurologic deficits that progress to cognitive impairment
- fatal
- Tx immunosuppression can lead to remission
subacute sclerosing panencephalitis (SSPE)
rare
in kids and adolescents several years after measles which usually occurs before 2 yrs of age
present with school and behavioral issues -> seizures and motor problems -> to coma and death
CSF increased IgG
affects grey and white matter
cryptococcosis
hematogenous dissemination from lung usually immunosupressed pts menigitis w/or w/o parenchymal cysts abscesses India ink CSF bird droppings
TB
meningeal signs and cranial nn palsies basal meningitis granular meningeal surface granulomas in 10% vasculitis like herpes inflammatory response more common in base of brain
bacterial cerebral abscesses
pts with infective endocarditis wound infection (post-op)
cerebral absesses
HA, fever, seizures, focal signs
mortality 10-30% w/Tx
50% have sequele
aspergillosis
one of more common mycotic infections of nervous system spores, pulmonary entry hematogeneous spread immunosuppressed hemorrhagic infarcts and abscesses very high mortality even w/Tx
neurocysticercosis
commonest parasitic infection of CNS leading cause of epilepsy worldwide
pork meat
can be asymptomatic
become calcified
toxoplasmosis in AIDs
CD4 <100
form abscesses
usually subacute variable presentation
Dx with imaging, CSF PCR
cryptococcus in AIDs
CD4 <50
spreads from lungs
chronic HA, fever, malaise
Dx with CSF- increased ICP, culture, Ag+
primary lymphoma in AIDs
CD4<100 DLBCL chronic decreased mental status HA, no fever, localizing signs Dx: imaging, Bx
PML in AIDs
CD4 demyelination
progession of multifocal symptoms in wks
Dx with CT
HIV dementia
CD4 <200
infection of neural cells w/direct and immune damage
broad neuropsychiatric and motor deficits
clinical Dx, imaging supportive
CJD
subacute progressive dementia with EEG changes and CSF finding (increased protein 14-3-3)
very long latent period
no Tx- fatal
can be sporadic, familial, iatrogenic, or variant
Dx- western blot
prions
porteinaceous infectious agents
no nucleic acid
not inactivated by typical steralization procedures
PrPc
normal protein
alpha pleated sheet
PrPsc
abnormal
beta pleated sheet
EXTREMELY protease resistant
CJD histo
spongioform degeneration with axonal and neuronal death
gliosis
Kuru histo
PAS stain
plaque formation
autoimmune encepalitis
anti-NMDA R encephalitis
usually pts have tumor elsewhere that produces neural tissue -> Ab generation -> cross BBB attack self
