Meningitis

Question 1

Which are the signs that prompt you to act on a suspicion of meningitis?

Answer 1

Any 2 of: Headache, pyrexia, neck stiffness, altered mental state. (If not yet in hospital gove 1.2g benzylpenicllin.

Question 2

Which are the organism that typically cause meningitis?

Answer 2

Meningococcus + pneumococcus.

Less commonly Haemophilus influenzae, Listeria monocytogenes, CMV, cryptococcus, TB if immunocomprimised.

Question 3

What is the differential diagnosis?

Answer 3

Malaria, encephalitis, septicaemia, subarachnoid haemorrhage, dengue fever, tetanus.

Question 4

What are the early and late features of meningitis?

Answer 4

Early - Headache, leg pains, cold hands and feet, abnormal skin colour.

Later:

• Meningism - neck stiffness, photophobia, Kernig’s sign (pain + resistance on passive knee extension with hip fully flexed)
• Consciousness level reduced, coma
• Seizures - about 20% +/- focal CNS signs, opisthotonus.
• Petechial rash - non-blanching, may be scarce or none.

Signs of galloping sepsis - slow cap refill time, DIC, reduced blood pressure, possibly increased pulse.

Question 5

What is the management plan for meningitis?

Answer 5

Start antibiotics - Cefotaxime 2g/6h slow I.V.

• Add Ampicillin 2g/4h I.V. if >55yrs or Listeria
• Aciclovir if viral encephalitis suspected
• Once organism isolated, seek urgent microbiological advice.

If ICP raised, get help, neurosurgeons.

Prophylaxis for contacts: rifampicin 600mg/12h P.O 2 days
or Ciprofloxacin 500mg PO 1 dose

Question 6

What are the investigations for meningitis?

Answer 6

1) FBC + U&Es + LFTs + glucose + coagulation screen
2) Blood cultures, throat swab, rectal swab, serology
2) LP - Usually done after CT has deemed it safe, opening pressure may be high, send CSF for cultures. In aseptic meningitis, sen CSF for PCR to look for viral cause e.g. enteroviruses, HSV type 2,
3) CXR - looking for signs of TB

Question 7

Describe the LP in bacterial meningitis:

Answer 7

Appearance - Often turbid
Predominant cell  - Polymorphs
Cell count - 90-1000+
Glucose - Reduced (1.5 g/L
Bacteria - in smear and culture

Question 8

Describe the LP in viral meningitis:

Answer 8

Appearance - Usually clear
Predominant cell  - mononuclear (lymphocytes)
Cell count - 50-1000+
Glucose - >1/2 the plasma level
Protein -

Question 9

Describe the LP in TB meningitis:

Answer 9

Appearance - Often fibrin web
Predominant cell - mononuclear (lymphocytes)
Cell count - 10-1000+
Glucose -