CNS Infections Flashcards
Meningitis is an inflammatory disease of the arachnoid and pia and defined by ____________________ in the CSF. It is a leading cause of acute ________________. Early diagnosis is crucial!
Major cause of bacterial meningitis:
1.
2.
These people are often sick.
abnormal white blood cells
confusional states
1. strep pneumo
2. neisseria meningitidis
What is the pathophysiology of bacterial meningitis?
colonization of mucus membranes of nasopharynx > tissue invasion > bacteremia > inflammatory response associated with release of inflammatory cytokines that promote BBB permeability, vasogenic cerebral edema, changes in blood flow and possible neuronal toxicity.
Half of patients with bacterial meningitis presents with these symptoms within 24 hours of onset…..
What are physical exam findings?
What is the classic tetrad (in reality theres 4 tho)
95% of patients will have two of these while 99-100% of pts will have at least one.
fever
confusion, lethargy
vomiting
headache
neck stiffness
PE:
1. meningismus - can be absent in very young and very old
2. brudzinski sign
3. kernig sign
4. seizures
Tetrad:
fever
neck stiffness
AMS
headache
What is the gold standard workup for bacterial meningitis?
What are the contraindications?
lumbar puncture
-opening pressure is elevated in 90% of cases
-protein 200-500 mg/dL
-glucose- lower than 40 mg/dL in 80% of cases
contraindications:
mass lesion- papiledema or focal deficits
-increased ICP > herniation
What is the treatment for bacterial meningitis ?
You also want to treat sepsis symptoms, what are they?
if the CSF is not clear and colorless, antibiotics should be started WITHOUT DELAY
Dexamethasone should be given before or during initial antibiotics in immunocompetent patients.
What is the empiric treatment?
vanco + ceftriaxone/cefotaxime and add ampicillin if > 50 y/o, neonate or immunocomopromised.
sepsis=fever and hypotension
What are the complications associated with bacterial meningitis?
HA
seizures
SIADH
cognitive disruptions and CN palsies
fatality is possible
What is the prevention for bacterial meningitis?
vaccines for h flu type B, N meningitidis and S pneumo
Rifampin for prophylaxis in household contacts and other close contacts x2 days
In viral meningitis, the cause can be determined by time of year, travel, immunosuppression. Brain function should be _______________.
Etiology:
1.
2.
What are the symptoms?
normal.
Etiology: enterovirus, herpesvirus
S/S:
1. HA
2. Fever
3. N/V
4. Rash?
5. stiff neck/ nuchal rigidity
6. photophobia
What are the three primary mechanisms of viral meningitis?
- spread of virus through the body via bloodstream
- neuronal spread of virus by axonal transport (herpes simplex,rabies)
- autoimmune post infectious demyelination (varicella)
What is the workup and treatment for viral meningitis?
CSF IS MOST IMPORTANT
-pressure will be normal to increased
- WBC count wont be as high as bacterial
-protein normal to slightly raised 80-200
-glucose usually normal
What is the treatment for viral meningitis? What is the prognosis?
acyclovir if HSV is suspected.
MUCH better than bacterial meningitis, not typically associated with long term complications.
What is encephalitis?
it is an infection of the brain parenchyma and It is manifested by neurologic dysfunction. In this infection, brain function is NOT normal. 1/2 of the patients are over 50.
What is the etiology of encephalitis?
HSV Type I is the most common fatal cause in the US along with west nile virus
What are the risk factors for neonatal encephalitis?
In adults, HSV II usually causes _________________
mother with HSV type II at birth, travel history
meningitis
What are the s/s of encephalitis?
Sequela: __________ and ___________ changes shows the predilection of HSV for limbic structures
behavioral changes
hallucinations
HA
stiff neck
vomiting
memory loss
aphasia
hemiparesis or flaccid paralysis
focal or generalized seizures
CN palsies
lethargy, coma
ataxia, tremors
weakness
memory changes, behavior changes