CNS Infection

Question 1

Meningism:

Answer 1

Headache
Nuchal rigidity
Photophobia

Opisthotonos
Kernig
–> Knee extension resisted
BrudiNski
–> Neck flex, knee flex
Upgoing Babinski

Question 2

Causative organisms meningitis:

Answer 2

BACTERIAL
- Neisseria meningitidis
- BABIES <3mo: GBS, Listeria, E.Coli (no BBB)
- KIDS: S.pneum, Hib
- ADULTS: Klebsiella, S.aureus,
- IMMUNO: Crypto, TB

VIRAL
- HSV 1 and 2
- Coxsackie, echo
- EBV, CMV, VZV

Question 3

Answer 3

Danger triangle

Skin –> meningitis.

Question 4

Empirical treatment of meningitis in >2mo/kids/adults:

Answer 4

1- DEXAMETHASONE 0.15mg/kg IV Q6H (< hearing loss)

PLUS

2- CEFTRIAXONE 2g IV (50/kg) Q12 (N.mening)
3- BENPEN 2.4g (60/kg)Q4
4- ACICLOVIR 10-20mg/kg Q8 (if enceph)

….ADD Vancomycin *if gram + returns (resistant pneumococcus) or MRSA risk

OFFER PROPHYLAXIS TO CLOSE CONTACTS!

Question 5

Empirical treatment of meningitis in neonates (<2mo):

Answer 5

Same, but:
- No steroids
- Swap ceftriaxone (which neos can’t have, for cefotaxime)
__________

CEFOTAXIME 50mg/kg
BENZYLPENICILLIN 60mg/kg
+- ACICLOVIR

Question 6

Prophylaxis (PEP) for N. meningitidis contacts:

Answer 6

Notify public health for contact tracing

PEP for:
STAFF:
- No PPE
- Mouth to mouth or intubation
CIVVIES
- Household/childcare level contacts
- Saliva sharing or sexual
- Passengers directly next to on trip >8hrs
—> Droplet transmission only

Infectious from 7 days prior, 24 hours post antibiotic completion

• Ceftriaxone 250mg IM x1
  or
• Cipro
  or
• Rifampicin (not if pregnant)

Question 7

When is a CT indicated prior to LP:

Answer 7

Anyone where raised ICP is possible/ expected:

• > 60
• Immunocompr.
• ALOC
• Focal neurology
• ICP features: brady, papillo

Question 8

Post-lumbar puncture headache: risk factors and features

Answer 8

• Large needle
• Bevelled, bevel not parallel to fibres
• Multiple punctures
• Large volume CSF drained
• Not replacing styler on withdrawal
• Failure to lie after procedure

10-20% risk in 48 hours
Feels worse upright

Lie flat
Caffeine
Blood patch

Question 9

Lumbar Puncture: CSF analysis

Answer 9

Question 10

What to request on CSF sample:

Answer 10

WCC
RCC
Xanthochromia
Cytology

Protein
Glucose

Gram stain
Crypto (India ink)
TB (Zeihl-Neelsen)

Culture

HSV and enterovirus PCR
Cryptococcus antigen

Oligoclonal bands (MS)

Question 11

Causes of encephaLITIS:

Answer 11

INFECTIVE:
–> TB, syphilis, Listeria
–> VIRAL: HSV, Japanese encephalitis, West Nile, ticks, rabies, bat bite
–> Cryptococcus
–> Malaria

AUTOIMMUNE:
–> AntiNMDA
–> Post viral
etc.