Infectious Disease (Block 6): Meningitis/meningoencephalitis

Front 1

for which age group is hematogenous dissemination (as opposed to local extension) for meningitis more likely?

Back 1

neonates > 6 to 24 months > elderly

Front 2

what 3 immunological deficits can a pt have to become more susceptible to meningitis via hematogenous spread?

Back 2

-asplenia(ie. sickle cell dz)
-antibody dysfunction
-terminal complement component deficiency

Front 3

what kinds of anatomical defects (both congenital and acquired) can a pt have to leave them susceptible to meningitis via local extension?

Back 3

congenital:
- meningomyelocele (spina bifida)
- dermoid sinus

acquired:
- trauma
- neurosurgical procedures
- invasive tumors

Front 4

besides an anatomical defect, what else can lead to meningitis susceptiblity via local extension?

Back 4

parameningeal focus (ie. sinusitis, otitis media, infection of skull, brain abscess)

Front 5

tell me the steps in hematogenous pathogenesis ==> meningitis. what are the 2 ultimate results?

Back 5

- requires transient bacteremia
- release of bacterial immunogenic products
- activation of inflammatory mediators:
1) activation of leukocytes --> cytotoxic edema (inc ICP)
2) endothelial injury --> increase in BBB permeability (leads to edema and inc ICP)
3) coagulation cascade --> thrombosis (leading to dec in cerebral blood flow)

2 results:
1) increase in ICP
2) decrease in cerebral blood flow

Front 6

name the most common cuase of bacterial meningtiis in adults and children

Back 6

S. pneumoniae (more likely to have altered consciousness/focal deficits; alcoholic cirrhotic pts and pts with sickle cell dz are sucsceptible)

Front 7

which etiology that causes meningitis can cause petechiae or purpura if bacteremia is present?

Back 7

Neisseria meningitidis (commonly outbreaks in young college dorms, military recruits; more common in winter/spring)

Front 8

which etiology of meningitis is often associated with otitis media?

Back 8

H. influenza type B (much less common with vaccine nowadays)

Front 9

what are the 3 most common etiologies of neonatal meningitis?

Back 9

Group B streptococcus (#1- agalactiae)

E. coli
Listeria monocytogenes

Front 10

pt has stiff neck and headache

Back 10

due to piaarachnoiditis

Front 11

pt has confusions and convulsions

Back 11

due to subpial toxic encephalopathy

Front 12

pt has ocular palsies and deafnss

Back 12

due to inflammation of vascular involvement of cranial nerves

Front 13

pt has focal seizures or cerebral deficits

Back 13

due to thrombosis of meningeal vessels

Front 14

pt has increased intracerebral pressure

Back 14

due to hydrocephalus

Front 15

CSF analysis of bacterial meningitis would show:

Back 15

highly increased PMNs(neutrophils)
decreased glucose
increased proteins
increased opening pressure

Front 16

CSF analysis of brain abscess would show:

Back 16

- increased lymphocytes
- normal glucose
- increased proteins
- increased openign pressure

Front 17

CSF analysis of TB/fungi would show:

Back 17

-increased lymphocytes
- decreased glucose
- increased protein
- increased opening pressure

Front 18

CSF analysis of viral meningitis woudl show:

Back 18

-increased lymphocytes
- normal glucose
- slightly increased proteins
- normal opening pressure

Front 19

brain abscess are due to _______ spread. what is it associated with?

Back 19

hematogenous

it's associated with congenital heart defects (such as right to left shunt)

Front 20

common presenation of brain abscesses in children

Back 20

children are sick for 10 days of non-specific symptoms (headache, fever, vomiting) then show in clinic with altered mental status/seizures

Front 21

tx of meningitis in neonates

Back 21

ampicillin/gentamicin

Front 22

tx of meningitis in infants/adults

Back 22

vancomycin, ceftriaxone

Front 23

tx of meningitis in elderly pts

Back 23

vancomycin, ceftriaxone, ampicillin (for listeria)

Front 24

what's the differnce bw primary vs. post- or para- infectious encephalitis

Back 24

primary - due to invasion of infectious agent in the brain or spinal cord

post/para-infectious - due to inflammation from non-CNS illness and can be immune mediated

Front 25

arboviruses (like WEEV, EEEV) cause what clincial manifestations? how does this differ from menningitis?

Back 25

confusion, plantar reflexes, seizures, CN palsies (compared to meningitis, Cn palsies show up later)