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Flashcards in CNS infections Deck (85)
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31

what causes bacterial meningitis in ages over 21

strep pneumoniae , neisseria meningitidis

32

what causes bacterial meningitis in overs 65s

streptococcus pneumoniae, listeria

33

what causes bacterial meningitis in the immunocompromised

S. pneumoniae, N. meningitidis, listeria, aerobic GNR

34

what causes bacterial meningitis in basilar skull fractures

s. pneumoniae, h. influenzae, beta hemolytic strep group A

35

what causes bacterial meningitis in head trauma/ post op

s. aureus, s epidermis, aerobic GNR

36

what causes bacterial meningitis in a CSF shunt

s. epidermis, S aureus, aerobic GNR, p. acnes

37

what are the possible complications of meningitis

as limb loss, deafness, blindness, cerebral palsy, quadriplegia and severe mental impairment

Purulence
Exudate around nerves (III, VI cranial nerves particularly vulnerable)

invasion and abscesses

cerebral oedema

ventriculitis/ hydrocephalus

38

what are the pathogeneses of bacterial meningitis

-nasopharyngeal colonisation (most common)
-direct (sinusitis, mastoiditis, brain abscess, skull defects/ fracture
-from remote foci of infection (endocarditis, pneumonia, UTI)

39

what do you analyse in CSF from a lumbar puncture

Tube 1. Hematology: cell count, differential
Tube 2. Microbiology: gram stain, cultures
Tube 3. Chemistry: glucose (will be low in meningitis as bacteria eating it), protein
Tube 4. Hematology: cell count, differential

opening pressure
lactate

40

what precautions must be made in lumbar punctures

be careful of raised ICP (dont do)
treat with antibiotics first in suspected bacterial infection

41

what CSF results are 99% predictive of bacterial meningitis

high WBC count
higher neutrophils
high protien
low glucose
low glucose (CSF/serum)

42

what are the typical CSF findings in viral meningitis

lymphocytes
protein normal/ slightly high
glucose usually normal
gram stain will be negative

43

what will the gram stain be in TB CSF analysis

may be pos or negative

44

what causes the symptoms in neisseria meningitis

endotoxin

45

who usually gets neisseria meningitis

young children

46

what does the rash look like in meningococcal infection

non blanching purpura that look like coalesced bruises

47

what does H influenza require for growth

blood factors

48

what is the most common cause of meningitis in children under 4

h influenzae

49

where is strep pneumoniae usually found- why is this important

nasopharynx

Hospitalized patients, patients with CSF skull fractures, diabetics/ alcoholics and young children are most susceptible to S. pneumoniae meningitis.

50

what tx for cryptococcus meningitis

will have very high ICP so give serial LPs and anti fungals (IV amphotericin A/ flucytosine, fluconazole)

51

who gets cryptococcus

HIV patients

52

what is the most common meningitis in immunocompromised

listeria

53

what are the features of cryptococcal meningitis

fungal
mainly in HIV disease
low CD4
disseminated infection
aseptic CSF

54

who gets listeria meningitis infections

neonates
>55s
immunosuprpessed (esp malignancy)

55

what antibiotic for listeria

IV amoxicillin (or ampicillin)

56

what are the features of tuberculous meningitis

reactivation, elderly
often non specific illness
previous TB on CXR
hard to diagnose- poor yield on culture

57

tx for TB meningitis

Isoniazid + rifampicin key (add pyrazinamide + ethambutol)

58

why can bacterial meningitis be culture negative

10-15% are anyway
pre LB use of oral antibiotics can lower culture

59

what other than bacterial meningitis can a neutrophilic & low glucose CSF mena

early viral
leakage of abscess into ventricle
TB

chemical meningitis
behcet syndrome
drug induced

60

what is aspetic meningitis

non pyogenic bacterial meningitis:
spinal fluid that contains
-low WBC
-minimally elevated protein
-normal glucose

can be lots of things other than viral meningitis