Define Tubercular Meningitis. Describe its stages, investigations, management and complications.

Definition

• Tubercular meningitis (TBM) is meningitis caused by Mycobacterium tuberculosis.
• It is a subacute, basal meningitis and the most serious form of extrapulmonary tuberculosis in children, with high morbidity if treatment is delayed.

Clinical Stages

• Stage I (prodromal) — non-specific: low-grade fever, malaise, irritability, anorexia; no focal signs.
• Stage II — meningeal signs, cranial nerve palsies (basal exudate), altered sensorium, raised ICP.
• Stage III — coma, dense deficits, decerebration.

Investigations

• CSF — lymphocytic pleocytosis, high protein, low glucose, and a fine 'cobweb' clot; AFB stain/culture/GeneXpert.
• Neuroimaging — basal exudates, hydrocephalus, infarcts, tuberculomas.
• Evidence of TB elsewhere (chest X-ray, Mantoux, contact history).

Management

• Anti-tubercular therapy (ATT) — an intensive multidrug regimen followed by prolonged continuation (longer than for pulmonary TB).
• Corticosteroids — reduce inflammation, oedema and mortality.
• Manage hydrocephalus (may need a shunt) and raised ICP; supportive care.

Complications

• Hydrocephalus (basal exudates blocking CSF flow), cranial-nerve palsies, and vasculitic infarcts (stroke).
• Tuberculoma, SIADH, and long-term neurological deficits.

Diagnosis — Supporting Evidence

• Evidence of TB elsewhere — chest X-ray (miliary/primary complex), a positive Mantoux, and a contact history.
• CSF GeneXpert/AFB improves confirmation; imaging shows basal enhancement and hydrocephalus.

Prevention

BCG vaccination reduces severe forms such as TBM and miliary TB in young children; early detection and treatment of infectious adult contacts and chemoprophylaxis of exposed young children are also important.

Key Points on Management

• Start ATT on strong clinical/CSF suspicion — do not wait for culture confirmation.
• Add corticosteroids; treat hydrocephalus and raised ICP; ensure adherence for the full prolonged course.