Flashcards in CNS Infections Deck (71):
4 Signs of increased ICP
-Abducens (6) palsy
List the cushings reflex triad
Are Kernigs and Brudinskis sensitive or specific for meningitis?
-both are very specific but not sensitive (5%, 95%)
Which clinical meningitis sign is most sensitive?
(but still not very sensitive, 30%)
CNS infection- pertinent labs
-blood + urine cultures
When is it appropriate to scan prior to LP?
-signs of increased ICP
What are the uses of the four tubes drawn during LP?
1- glucose and protein
2- cell count
3- gram stain, routine culture
4- viral studieqs, VDRL
What should never be tested from tube 1 in LP?
-culture and gram stain, skin flora in tube one
How quickly is CSF normally replenished?
-half mL per minute
normal volume = 140 mL
Normal CNS glucose levels
2/3 serum glucose, 1/3 or less very sensitive for bacterial meningitis
How can protein levels be evaluated in traumatic tap?
-protein up 1 for every 700 RBCs
How many mononuclear WBCs are typically in CSF?
Proper position for LP opening pressure determination?
-lateral decubitus, not prone
What type of meningitis has normal opening pressure?
-fungal CAN be normal or low, other types at least slightly elevated
What type of meningitis has normal glucose?
-viral, all others have low glucose, esp bacterial
What type of meningitis has normal protein?
-viral, all others have high protein, esp bacterial
What type of meningitis involves RBCs in CSF?
List the normal number of WBCs in CSF for each meningitis etiology:
-bacterial: over 200
Cell type predominant in CSF for bacterial, viral, fungal and TB meningitis
-mono except in bacterial = PMNs
Frequent bacterial meningitis bug across all age groups
Top 2 bugs in neonatal meningitis + empirical treatment
-amp & gent
Top 2 bugs in 1-23 month olds + empirical treatment
1- strep pneumo
2- n men
ceftriaxone + vanc
Top 2 bugs in 2-18 year olds + empirical treatment
1- n men
2- strep pneumo
(GBS, Listeria also possible)
ceftriax + vanc + amp
19-59 top 2 meningitis bugs + treatment
ceftriax + vanc
Top 2 bugs in elderly meningitis + empiric treatment
-ceftriax, vanc, amp
Treatment for GBS meningitis (2)
Treatment for neisseria meningitis (2)
**may add dexamethasone
Strep pneumo meningitis treatment
-ceftriax + vanc if penicillin resistant
Listeria treatment in meningitis
amp and gent
Treatment for gram - meningitis
-ceftriaxone or cefotaxime
Px for n meningitis
-rifampin 2 weeks or ceftriax one dose IM
Long term effects of bacterial meningitis
Mortality rate encephalitis
Common encephalitis origins
arboviruses (west nile, eastern equine)
Nonviral causes of encehpalitis in the immunocompromised
When bacterial infections involve the brain they are called ____
cerebritis vs abscess depending on whether capsule exists
At what CD4 count is AIDs patient at risk of encephalitis?
Risks for encephalitis aside from immunosupression
-bats, mosquito exposure
(in endemic areas)
Encehpalitis workup: how do labs differ from meningitis workup?
-send CSF for cytology to evaluate for cancer cells
Basic lab added to encephalitis workup
Imaging most sensitive for diagnosing viral encephalitis
Treatment for HSV, VZV, EBV encehpalitis
Treatment for CMV encephalitis
Treatment for lacrosse california encehpalitis
Viral encephalitis with highest number of neuro sequelae
eastern equine (80%)
how commonly do they cause abscess?
Where do they most commonly form abscess in brain?
cause of 33% abscesses
Common otitis/mastoiditis organisms?
-what bugs are implicated
-where might they form cerebral abscess?
How commonly are brain abscesses a result of hematogenous spread?
MC symptom of brain abscess?
60% focal deficits, 35% seizure
Typical antibiotics for abscess?
Neurosurg abscess drugs
ceftaz and vanc to cover staph and pseudomonas
When should steroids be given for abscess?
only if there is significant edema
MC cause subdural empyema
extension of sinus infection or meningitis
Treatment for subdural empyema
-burr hole + drainage
-cefotaxime + metronidazole
Cause of epidural empyema
#1 sx/skull fracture
-also mastoiditis, sinusitis, otitis
Treatment epidural empyema
#1 cause meningitis in AIDs patients
C. neoformans animal assc
pigeon soil --> inhaled --> blood --> meninges
Stain for cryptococcus
Treatment for cryptococcus
At what CD4 count is toxoplasmosis a concern in HIV patients?
How is diagnosis made?
How is toxoplasmosis treated?
pyrimethamine + leucovorin
What is toxo px for AIDs patients
TMP SMX daily until CD4 is greater than 200
What part of the brain is most susceptible to toxo?
Bug assc with neurocysticercosis