Tuberculous Meningitis


Mycobacterium tuberculosis meningitis, TB meningitis, tuberculoma, tuberculous meningovasculitis


Clinical features plus confirmatory CSF analysis or TB studies

Findings in Investigations:

  • Findings remain after 10 days treatment
  • White cell count: moderately high,
    • Usually <500/microL, (100-300/mm3)
    • Mainly lymphocytes
  • Protein: High, >0.8g/L
  • Glucose: Low ,<2.2 mmol/l
  • Or atypically:
    • Neutrophilia if early, normal protein, normal glucose
    • Eosinophilia may occur
  • Acid fast stain positive in 20%
  • Culture is positive in 80%
  • CSF PCR: for TB


  • Tuberculomas: gadolinium enhancement, nodular
  • Infarctions in vasculitis


  • In vasculitis diffuse narrowing of the arteries. However, affected blood vessels are typically small and may not be abnormal on MRA


  • Proximal carotid artery & basilar artery stenosis: vasculitis of “basilar meningitis”
  • May be normal



  • Grey pus in the subarachnoid space, usually basal. Tuberculoma= round/oval mass with necrotic creamy centre.


  • Granuloma. Caseating necrosis, Langhan multinucleated giant cells, histiocytes, lymphocytes, plasmacytes. Surrounding gliosis in tuberculoma.
  • Obliterative endarteritis= thickened intima by collagen. Fibrinoid necrosis & thrombosis of meningeal vessels.
  • Ziehl-Neelsen stain: Acid fast (red) bacilli.

Treatment options:

Treat early, on clinical suspicion before confirmation by diagnostic tests
TB chemotherapy:

  • Look up the updated regimen. Here are examples
  • WHO regimen:
    • 2 months P.O.: isoniazid +rifampin +pyrazinamide +ethambutol
    • +4 months P.O. continuation: isoniazid +rifampin
  • Infectious Diseases Society of America (IDSA) regimen:
    • 2 months P.O.: isoniazid +rifampin +pyrazinamide +ethambutol
    • 9-12 months continuation: isoniazid +rifampin
  • Immunomodulation i.e. corticosteroids, NB. rifampin increased the dose needed


  • Non-communicating:
    • Immediate ventriculoperiotoneal shunt or external ventricular drain
  • Communicating:
    • Consider medications: frusemide +acetazolamide
    • Consider ventriculoperitoneal shunt

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