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
What is the recommented antimicrobial therapy for N. meningitidis?
3rd generation cephalosporin
What is the recommented antimicrobial therapy for Streprococcus pneumoniae?
vancomycin + 3rd generation cephalosporin
What is the recommented antimicrobial therapy for Listeria monocytogenes?
ampicillin or penicillin G
Who are “close contacts” that should receive prophylaxis in the case of a patient with bacterial menigitidis?
- houselhold or day-care members who sleep or eat in the same dwelling as index patient
In what cases do healthcare workers receive chemoprophylaxis for a patient with bacterial meningitis?
if they come in close contact whith the patient’s secretions (ie. mouth to mouth resuscitation)
What is the antibiotic prophylaxis for contacts of patients with H. influenzae meningitis?
rifampin 10mg/kg 2x/day for 4 days
What is the antibiotic prophylaxis for contacts of patients with N. meningitidis meningitis?
rifampin 10mg/kg 2x/day for 2 days
OR
single 500mg ciprofloxacin
Since rifampin & ciprofloxacin is contraindicated in pregnant women, this population should take what for meningitis prophylaxis?
single 250mg dose ceftriaxone
What is the causative agent & symptoms of Lyme Disease?
Treatment?
borrelia burgdorferi
affects skin, heart, nerves & joints
doxycycline
What are the characteristics of the first stage of lyme disease?
eyrthema migrans “bulls eye”
flu-like symptoms (headache, malaise, fatigue, or myalgias)
What are the characteristics of the Stage 2: Early Disseminated Lyme disease?
- acute neuroborreliosis - weeks, months
- malaise, fatigue, lymphadenopathy
- nervous system
- meningeal signs (headache, neck stiffness, difficult concentrating, cranial nerve dysfunction, radiculopathies, ataxia)
- cardiac system
- A-V block, myopericarditis, pancarditis
- lyme arthritis
What are the characteristics of Stage 3: Late Chronic Lyme Diseae?
- nervous system & joints continuous inflammation > 1 yr
- cognitive changes & fatigue
- lyme encephalopathy, polyneuropathy & leukoencephalopathies
- chronic arthritis
- lymphocytoma; acrodermiatis, chronica atrophicans
What is the causitive agent & treatment for neurosyphilis?
Treponema pallidum
Penicillin G
What are the 5 types & characteristics of Neurosyphilis?
-
Syphilitic
- weeks - years after infection (Argyll Robertson pupil; CN)
-
Meningovascular
- 7-10yrs after infection (prodromal symptoms, psychiatric abnormalities, paraplegia, arteritis, stroke)
-
General paresis
- 3-30 yrs after infection (chronic dementia, Argyll pupil, delusions, change in personality)
-
Tabes dorsalis
- 5-50 yrs after infection (vision loss, losso of reflexes, sensory gait, loss of tracts of posterior columns- proprioception & vibration)
-
Gumma
- soft, non-cancerous, granulomatous growth
What is Argyll Robertson pupil?
constricts with accomodation but not reactive to light
Where is Histoplasmosis geographically found?
Ohio, Missippi River Valley, caves
Where is Coccidiodes immitis demographically found?
Southewestern USA, Northern Mexico
Where is Cryptococcus neoformans demographically found?
bird droppings, soil, decaying wood
What is the first-line treatment for fungal meningitis?
2nd line?
Amphotericin B
2nd - Fluconazole
What is the most common cause of meningitidis in patients with AIDS?
Cryptococcus neoformans
What parasitic infection is one of the most common causes of acquired epilepsy in the world?
How is it acquired?
Taenia solium
ingestion eggs of pork tapeworms (incubation months - years)
