CNS infections Flashcards
bacterial meningitis
inflammation of meninges of the brain and spinal cord caused by bacterial infection
pathogenesis bacterial meningitis
infection causes changes to the blood brain barrier –> entry of infection organisms into the brain of CSF
what bacteria are responsible for bacterial meningitis in neonate
group B streptococcus
E.coli
listeria monocytogenes
what bacteria are responsible for bacterial meningitis in adults
steptococcus pneumoniae
nissieria meningitis
where are infection found in those with bacterial meningitis
mucosal surfaces in the upper respiratory tract
where does inflammation begin bacterial meningitis
subarachnoid space
then spreads
what leads to decreased cerebral perfusion and ischemic lesions bacterial meningitis
vasculitis and thrombotic obstruction
clinical manifestations bacterial meningitis
fever and headache associated w/ stiff and painful neck
pain in lumbar area and posterior aspects of thigh
kernig’s sign, brudzinski’s sign
diagnosis bacterial meningitis
lumbar puncture
treatment bacterial meningitis
neurologic emergency
antimicrobial therapy
dexamethasone to reduce subarachnoid inflammation
brain abscess
intracranial mass lesions d/t local infection caused by microorganisms
may develop from sinusitis or mastoiditis (chronic sinus infections)
pathogenesis brain abscess
evolve over a number of stages
cerebrum involvement
infiltration of inflammatory cells
increased perivascular inflammation
necrosis
early capsule formation
necrotic center shrinks and decrease inflammatory cells
cerebrum involvement
1-3 days
infiltration of inflammatory cells
24 hrs
increased perivascular inflammation
3 days
necrosis
4-9 days
early capsule formation
10-13 days
necrotic center shrinks and decrease inflammatory cells
14 days to 5 weeks
clinical manifestations brain abscess
nuchal rigidity
nausea
vomiting
seizures
visual disturbance
dysarthria
hemiparesis
sepsis
symptoms similar to brain tumors but progress more rapidly
diagnosis brain abscess
history of infection/immunosuppression leads to suspicion
MRI supports diagnosis
prognosis brain abscess
nearly half of pts are left with some neurologic dysfunction
encephalitis
acute inflammatory disease of brain tissue d/t viral invasion or hypersensitivity
first in great matter (nerve cell bodies of CNS)
how is encephalitis carried
mosquitoes or ticks
–> hemorrhagic necrosis and multinucleated giant cells
clinical manifestations encephalitis
headache
nausea
vomiting
focal neurologic signs
west nile virus
