Meningitis/Encephalitis Flashcards Preview

Hailey - Neuro > Meningitis/Encephalitis > Flashcards

Flashcards in Meningitis/Encephalitis Deck (48):
1

listeria mortality rate

25%
gram + rod (positive purple listeria)

2

listeria empiric Tx

definitive Tx

ceftrixone and ampicillin

definitive: ampicillin and gentamicin
Gentlemen get amped up on Listerine.

3

most common cause VIRAL M&E in summer/fall

enterovirus

4

cell wall inhibitors mech (general)

inhibit transpeptidation of peptidoglycan (inhibit cell wall* synthesis)

5

Listeria monocytogenes
gram ___
big 3 and ___
virulence

gram + rod (purple positive listerine)
big 3 and nuchal rigidity and diarrhea from soft cheese, deli, etc.

internalin induces phagocytosis
phospholipase and listeriolysin O allow escape
actin tail

6

if focal mass lesion, labs

no LP -- increased risk of brain herniation = BAD

7

risks with 3rd generation cephalosporin: ceftriaxone

increased risk of neurotoxic side effects

8

Why treat empirically with ceftriaxone?

bactericidal
small
lipophilic
can cross BBB
not a ligand for efflux pumps
streptococci +
serious gram -

9

most aggressive empiric treatment combo

ceftriaxone
vancomycin
acyclovir
dexamethasone

10

encephalitis vs encephalopathy

encephalitis: infection (fever, headache, focal neuro signals, seizures)

encephalopathy: diffuse cerebral dysfunction WITHOUT inflammation, usually due to toxin or metabolic dysfunction

11

where's waldo:
meningitis
encephalitis
abscess
myelitis

m: subarachnoid space
e: diffuse parenchyma
a: focal parenchyma
my: spinal cord

12

etiology of encephalitis

33-66% unknown
then viral (entero, adeno, herpes, rabies)
also nonviral (ricketssia, mycoplamsa, ADEM)

13

STAT TO DO with CNS infection

1. H and P*
2. blood culture*
3. start abx*
4. neuroimaging*
5. LP/biopsy
6. ID organism (gram stain/PCR/RT-PCR)
7. switch to definitive Tx

14

BM labs

increased pressure
increased WBC
>80% PMNs
elevated protein
decreased glucose

15

VM labs

mod WBC count
>50% Ls
<20% PMNs
mod protein
normal glucose

16

FM labs

increased pressure
m100 WBC
>50% Lymphocytes
mod elevated prto
normal glucose

17

Aseptic meningitis

> 85% VIRAL: enterovirus/picornavirus, HSV2, arthropod, HIV
highest incidence within 12mo old

Sx: fever, HA, photophobia, dec nuchal rigidity, change mental status

CSF: increased Lymphocytes and PMNs, mod inc protein, normal glucose

Tx: supportive therapy
can be fatal in neonatal period

18

Septic meningitis

BACTERIAL: streptococcus pneumonia+ lancet (adults), neisseria meningitides - diplococci (teen/college), homophiles influenza type B - pleomorphic (babies, w/ no vaccine)

Sx: fever, nuchal rigidity, iritability, neuro dysfxn

CSF: inc PMNs, inc protein, dec glucose

LIFE THREATENING, PROMPT EMPIRIC TX
ceftriaxone, vanco (MRSA), acyclovir (HSV2), cefeprime (psuedomonas), ampicillin (listeria)

19

Chronic meningitis

SPIROCHETES - treponema pallidum/syphilis, borrelia burgdorfori
MYOCBACTERIUM TUBERCULOIS (india ink*)
FUNGI - cryptococcus neoformances, coccoides, candida albicans
IMMUNOCOMPROMISED

Tx: 4 drugs RIPE
Ri
Isoniazid
P
E

20

TORCH infections (perinatal)

Toxoplasma
Other: syphilis, VZV, parvovirus B19, group B strep, e. coli
Rubella (german measles)
CMV cytomegalovirus
HSV-2/HIV

21

HSV associated with

temporal lobe (would see on MRI)

22

BM gross

PURULENT/PUS
particularly dense over engorged blood vessels

23

VM gross

swollen, or look normal (no pus/exudate)

24

BM micro

NEUTROPHILS inside vessels = phlebitis, into brain tissue = cerebrates
FIBRIN in exudate: healing stage in exudate > BAD = disrupts absorption of CSF > hydrocephalus

25

VM micro

lymphocytic infilatrion, mild
mononuclear: round, dark cell

26

mycobacterium tuberculosis

more chronic fashion
acid fast
basal exudate that obliterates cisterns (interferes with cistern magnum and CNs)
exudate more GELATINOUS/CREAMY
ADHESIONS/STRINGY
MONONUCLEAR CELLS
GRANULOMAS: obliterative endarteritis
caseating
hisitocytes

27

pathology of acute inflammation

neutrophils
vessels larger and leakeir
"busy"
mickey mouse nuclei

abscess: neutrophils stick around
circumscribed collection of pus, GREEN NEUTROPHIL EXUDATE

chronic: mononuclear cells, more uniform than "busy"

28

gliosis

astryocyte rxn to injury

29

migroglial cells

proliferate around single neuron dying off, around areas of necrosis

30

hydrocephalus from meninigitis...how

if healing blocked ventricles = communicating = all vent sys involved

31

CNS infections

Meningitis: Neiserria, strep pneu, h influ, fungal
Encephalitis: viral (herpes)
Abscess: strep, staph

32

abscess

mix of bacteria:
strep
pseudomonas
haemophilus
staph
bacteroides

33

enterovirus

single stranded + sense RNA
capsid
no envelope

34

transmission/development

muscosal colonization > invasion and multiplication in bloodstream > cross BBB > in CSF > release inflammatory cytokines in CSF by astrocytes and microglia > increased perm BBB > diapedesis of leukocytes > edema > inc ICP > HA > neuronal injury

35

virulence factors

capsule IMPT
IgA protease
Pili help attach to mucosa
endotoxin (by gram -)
outer membrane proteins

36

Neisseria meningitides virulence special

LOS: looks like brain sphinoglipids, so is recognized as self
skin rash
transmitted through respiratory droplets

37

H flu type B special because

B capsular polysaccharide help facilitate its invasion into the brain
CHOCOLATE AGAR

38

Mycobacterium tuberculosis special because

ACID FAST bacilli stain
RIPE Tx

39

RIPE Tx

Rifampin - inhibits dDNA RNA pol, inhibits cypP450
Isoniazid - inhibits mycolic acids
Ethambutol - inhibits cell wall synthesis by binding arabinysyl transferase
Pyrazinamide

40

cryptococcus neoformans special because

INDIA INK STAIN
inhaled as spores, like yeast
in IC
fluconazole 4 lyfe

41

site of herpes latency

NEURON

42

herpes viruses are Baltimore class

Class I
ds DNA

43

VZV most comomon cause of encephalitis among

IC patients
particularly if have HIV/AIDS or stem cell transplantation

44

only alpha herpes virus produce

thymidine kinase
so can use acyclovir

45

acyclovir

DNA polymerase chain inhibitor, stops new DNA made, dGTP switched out

46

Tx betaherpesviruses

gancyclovir

47

post-infectious encephalitis

ADEM acute disseminated encephalomyelitis MOST COMMON
inflammatory demyelinating condition, monophasic, pediatric usually, days to weeks post-inf

also
APME acute disseminated encephalomyelitis (demyelination, M and S defects)
SSPE subacute sclerosing panencepthalitis MOST SCARY

48

measles virus

Class V, ssRNA -
enveloped