Viral CNS Infection

Question 2

important physical exam findings to rule out when suspecting viral meningitis

Answer 2

pulmonary: rule out pneumonia; dermatological: rash could indicate bacterial

Question 3

important lab tests to rule out when suspecting viral meningitis

Answer 3

test for syphilis, HIV; looks at WBC count and determine if monocyte or neutrophil predominance (neutrophil means bacterial); urine; chest x-ray for TB; CSF glucose and protein, CSF gram stain

Question 4

when a person presents with fever and headache, what are our two largest concerns?

Answer 4

meningitis & encephalitis (or combination)

Question 5

if it is acute meningitis, what organisms would we suspect?

Answer 5

enterovirus, strep pneumo, neiss meningitidis

Question 6

if it is chronic meningitis, which organisms would we suspect?

Answer 6

mycobacteria TB, fungal, sarcoid, malignancy

Question 7

encephalopathy

Answer 7

altered consciousness with no evidence of inflammation in the CNS on imaging or CSF analysis

Question 8

encephalitis

Answer 8

altered consciousness, evidence of CNS inflammation or imaging (virologically confirmed if pathogen identified in CSF by culture/PCR)

Question 9

meningism

Answer 9

headache with neck stiffness and/or photophobia; NO evidence of altered consciousness or inflammation

Question 10

purulent meningitis

Answer 10

meningism (headache, photophobia and/or stiff neck) with high WBC, predominance of PMNs, low glucose, high protein (microbiologically confirmed if pathogen identified)

Question 11

aseptic meningitis

Answer 11

meningism with moderately high WBC (lymphocyte predominance), normal CSF glucose, high CSF protein (viral, TB)

Question 12

prisoner, homeless, or immigrant is at greatest risk for what type of meningitis?

Answer 12

chronic from mycobacterium TB

Question 13

Ohio River Valley is associated with what bacterial meningitis?

Answer 13

subacute histoplasma

Question 14

agammaglobulinemia is associated with what form of meningitis?

Answer 14

chronic enterovirus meningitis

Question 15

NSAID use is assoc. with what form of meningitis?

Answer 15

drug-induced acute meningitis

Question 16

HIV is assoc with what meningitis organisms?

Answer 16

toxoplasma abscess, cryptococcal meningitis, HIV/CMV meningoencephalitis

Question 17

splenectomies increase susceptibility to meningitis with what organisms?

Answer 17

encapsulated orgs like n. meningitidis

Question 18

what organism causes recurrent meningitis?

Answer 18

HSV-2

Question 19

what are the 4 ways in which viruses can enter the CNS?

Answer 19

1. directly across cerebral capillary endothelial cells (infect endo cell, infect glial cell, carried by infected monocyte), 2. infect choroid plexus epithelium (more permeable), 3. along olfactory nerves, 4. along peripheral sensory nerves

Question 20

name 2 noninfectious causes of meningitis

Answer 20

auto-immune diseases (looks like viral), NSAIDS, sulfa drugs (looks like bacterial)

Question 21

emergency management for a patient with suspected meningitis

Answer 21

1) drop/air precautions, 2) resuscitate if necessary, 3) blood cultures from 2 locations, 4) lumbar puncture within 30 min, 5) empiric antibiotics, 6) CT or MRI if lesion expected

Question 22

74% of aseptic meningitis cases in children were a result of _____________.

Answer 22

enterovirus

Question 23

the top 3 bacterial causes of meningitis in children were?

Answer 23

strep pneumo, neiss meningitidis, GBS

Question 24

major causes of viral meningitis

Answer 24

enterovirus (very common, in the summer, coxsackie, echo, dx by PCR) & herpesviruses (HSV, VZV, CMV, HHV6); also influenza A, HIV, West Nile

Question 25

bacterial causes of aseptic meningitis

Answer 25

spirochetes, mycoplasma, mycobacteria

Question 26

evidence of enteroviral meningitis

Answer 26

exanthem, conjunctivitis, pericarditis, HFM disease, herpangina, pleurodynia in late summer/early fall

Question 27

CEMA

Answer 27

(rare) chronic enteroviral meningoencephalitis in agammaglobulinemia: HA, seizures, hearing loss, coma, weakness, ataxia, loss of cognitive skills

Question 28

who dies from enteroviral meningitis?

Answer 28

the very young and the old (about 5% of each)

Question 29

what is the greatest cause of encephalitis in the US?

Answer 29

UNKNOWN (as much as 86% of deaths, 60% of hospitalizations)

Question 30

symptoms of HSV encephalitis

Answer 30

abnormal CSF with high protein, normal glucose, lymphocyte predominance, and RBCs in CSF; focal EEG or MRI positive necrotizing, usually temporal lobe lesion

Question 31

what % of West Nile virus infections are asymptomatic, fever, or neuroinvasive?

Answer 31

80% asymptomatic, 20% fever, less than 1% neuroinvasive disease (usually elderly)

Question 32

diagnosing CMV encephalitis

Answer 32

acute deterioration in mental status with elevated protein in CSF (HIV, transplant patients)

Question 33

subacute sclerosis panencephalitis

Answer 33

acute encephalitis secondary to measles; causes personality changes, myoclonic jerks, recurrent falls, rigidity -- death within 3 years

Question 34

JC virus

Answer 34

polyoma virus, 90% sero+ by middle age, causes PML in immunocompromised due to reactivation

Question 35

PML

Answer 35

cytolytic replication of JC polyomavirus in oligodendrocytes of brain (demyelinating) -- focal motor and sensory deficits, gait abnormalities, speech, HA, visual impairment

Question 36

how do you dx PML?

Answer 36

brain biopsy (invasive), JC DNA in CSF, MRI shows lesions in white matter

Question 37

spongiform encephalopathy

Answer 37

prion disease: Kuru, Creutzfelt-Jakob disease; prions cause protein aggregation and fibril formation