CNS Infections - Fremont-Smith Flashcards
subdural abscess
aka subdural empyema
spread - air sinuses/middle ear
no antibiotics can get here
large - can compress
meningitis
infection of arachnoid membrane, subarachnoid space, or CSF
aseptic CSF
viral
-monocytes
may see increased pressure and protein
bacterial CSF
polys
- low glucose
- very high pressure and protein
lymphocytes in CSF
viral
aka septic meningitis
fever, lethargy, HA, neck stiffness, altered mental status
acute bacterial meningitis
purulent
bacterial
most common infection of CNS
acute purulent leptomeningitis
- bacterial
- aka just meningitis
mortality - due to cerebral edema and herniation
pus
bacterial meningitis
herpes
shift from leukocytes to lymphocytes
whatever in CSF
brought to brain parenchyma
-via virchow robbin space
most common aseptic meningitis
enterovirus E71
bacterial meningitis birth to two months
E. coli
group B strep
listeria
bacterial meningitis two months to five years
strep pneumo
meningococcus
bacterial meningitis in older child/adult
strep pneumo neisseria meningitidis (epidemics)
bacterial meningitis in elderly
strep pneumo
group B strep
e. coli
listeria
bacterial meningitis in epidemics
neisseria meningitidis - meningococcus
aseptic meningitis
may be due to drug rxn
vessel inflammation and thrombosis
occurs with bacterial meningitis
-also see pus
encephalitis
inflammation of brain parenchyma
common cause of viral encephalitis
CMV - young fetus
herpes
HIV
also rabies, PML, and SSPE
herpes encephalitis
remains latent in the trigeminal nerve
w/out tx - fatal**
necrosis of base of frontal and temporal lobes
herpes encephalitis
fatal if not treated
herpes encephalitis
necrosis of base of frontal and temporal lobes and intranuclear inclusions
herpes encephalitis
giant cells - multinucleated
neonatal HSV encephalitis
diffuse melt down of brain
-without predilection for frontal and temporal lobes (different than adult)
fetal CMV encephalitis
microcephaly, abnormal gyri, hydrocephalus, periventricular calcifications
periventricualr calcifications
seen with CMV encephalitis
rabies
rhabdovirus
from animal bite - travels axons
variable incubation
clinical rabies
HA, fever and malaise, swallowing difficulty
-furious and dumb forms
to stupor, coma, death
negri bodies
rhabdovirus
accumulation of protein made by the virus
preference of rabies
to hippocampus and cerebellum
PML
progressive multifocal leukoencephalopathy
-polyomavirus
brain - JC type
kidney and bladder - BK type
path of PML
polyomavirus infects and destroys oligodendrocytes
destroys white matter
see intranuclear viral particles
PML
often asymptomatic in humans
-reactavation - with immunodeficiency
focal neuro deficits that progress over months
PML
prognosis of PML
almost invariably fatal
tx of underlying immunosuppression - can cause remission
intranuclear viral particles
in PML
polyomavirus JC
infect oligodendrocyte - loss of myelin
SSPE
subacute sclerosing panencephalitis
-measles virus
measles path
infect grey and white matter
- massive necrosis
- usually to death
bird shit
cryptococcosis
cryptococcosis
heme spread from lung
- in immunosuppressed
- life-threatening - in AIDS patient
abscess formation
india ink stain
for cryptococcosis neoformans
- large polysaccharide capsule - visualized by india ink stain
- encapsulated yeast
also PAS stain
cyst formation
cryptococcosis
organism in the virchow robin space
PAS stain
detect polysaccharide
-schiff - purple-magenta counter stain
id CT, mucus, glycocalyx, basal lamina
-fungal infection
CSF with neutrophils, low glucose, and high protein
bacterial meningitis
meningeal signs, CN palsy, basal meningitis, granular meningeal surface
tuberculosis
form tuberculoma
potts disease
TB of vertebra
acid fast stain
mycobacterium
caseous granuloma with macrophages
tuberculosis
cerebral abscess
walled off - neovascularization
bacterial, fungal, protozoal
trauma, surgery, or hematologic spread
anterior cerebral abscess
from sinus - polymicrobial
temporal cerebral abscess
from mastoiditis - ear infection
multifocal cerebral abscess
hematologic spread
ring lesion
neovascularization around cerebral abscess
toxoplasmosis
cat feces
activate when immunosuppressed
thin walled cyst
toxoplasmosis
immunohistochemistry
to ID toxoplasmosis
aspergillosis
spore - lung entry
- hematogenous dissemination
- 45 degree branching
45 degree branching hyphae with septa
aspergillosis
neurocysticercosis
commonest parasite infection of CNS
leading cause of epilepsy worldwide
pork meat
neurocysticercosis
focal or generalized seizures, papilledema, HA, vomiting and ataxia, vertigo, focal motor and sensory deficits, dementia, hydrocephalus, sudden death
neurocysticercosis
numerous cysts that calcify in brain
neurocysticercosis
toxoplasmosis in AIDS
CD4 <100
cryptococcus in AIDS
CD4 <50
primary lymphoma in AIDS
CD4 <100
PML in AIDS
CD4 <200
JC polyomavirus
HIV dementia
CD4 <200
prion
protein infectious agent
creutzfeldt-jacob disease
subacute progressive dementia
-tx - none
PrP-SC
abnormal folded protein (beta-pleated)
induces PrP-C (alpha-pleated) to become abnormal
kuru
caniballistic prion disese
-new guinea - brain eating
14-3-3
creutzfeldt jacob disease
spongiform degeneration
in CJD
vacuoles in parenchyma
axonal and neuronl death
brain fixed in formalin
does not destroy prion protein
definitive diagnosis of CJD
western blot
ovary/testicle teratoma
can lead to autoimmune encephalitis
auto-Ab against neural tissue develops
familial CJD
conversion happens at higher rate
