Non-viral infections of the CNS Flashcards
What are the mechanism of CNS infection?
- Direct seeding
- foreign objects, operative procedures
- hematogenous spread
- nasopharynx, bloodstream, subarachnoid space, corsses BBB
What are the major sources of infection that lead to CNS infection?
- skull fracture
- otitis media/mastoiditis/sinusitis
- pneumonia
Which etiological causes of bacterial meningitis have the highest rate of mortality?
- S. pneumonia (19-26%)
- H. influenzae (3-13%)
- N. meningitides (3-13%)
What complications can arise from bacterial meningitis?
hearing loss, memory difficulty, learning disabilities, brain damage, gait problms, seizures, kidney failure, shock
What are the most common cuases of bacterial meningitis?
-
S. pneumoniae
- a/w pneumonia or ear/sinus infection
-
N. meningitidis
- a/w URI
- highly contagious
-
H. influenzae
- resp spread
- a/w pneumonia - cellulitis, epiglotitis, arthritis
-
Listeria monocytogenes
- unpasteurized cheases, hot dogs, lunchmeats
What history is especially important to gather if you suspect a patient has bacterial meningitis?
- recent illness/sick contacts
- immunizations
- contact w/ animals or insects
- immunocompromised
- recent travel; geographical location
- trauma
What is the classic meningitidis triad?
fever
nuchal rigidity
altered mental status
What are the symptoms of meningitis in neonates?
hypotonia, irritability, poor feeding
What is Kernig’s sign?
have patient laying flat & you flex the hip up to 90 degrees & slowly extend the knee - (+) is if knee cannot be fully extended
What is Brudzinski’s sign?
have kid laying down on back, passively flex neck - (+) flexion in both legs
What is the last layer you will encounter when doing a lumbar puncture before reaching the epidural space?
ligamentum flavum
What are the characteristics of a CSF profile for bacterial meningitidis?
- bacterial
- high WBC (neutrophilic predominant)
- low glucose & high protein
- often be cloudy / yellowish
What is the treatment for suspectied bacterial meningitis?
- supportive
- empiric treatment
- meningoencephalitis - corticosteoids & antibiotics and acyclovir
- monitor for seizure (if indicated)
- manage intracranial hypertension (if indicated)
What drug should be given prior to first antibiotic dose to reduce hearing loss & mortality?
dexamethasone (10mg)
What is the recommented antimicrobial therapy for H. influenzae type b?
3rd generation cephalosporin