Inclusion of Mechanical Ventilation in Severity Staging of Tuberculous Meningitis Improves Outcome Prediction

Patients with tuberculous meningitis (TBM) in any stage of the British Medical Research Council (BMRC) scale, if requiring mechanical ventilation (MV), are likely to have a poor outcome. We report the usefulness of BMRC, BMRC-MV, and BMRC-hydrocephalus (BMRC-HC) staging, and Haydarpasa Meningitis Severity Index (HAMSI) scoring in predicting the outcome of TBM. One hundred ninety-seven TBM patients were analyzed from a prospectively maintained TBM registry. The severity of meningitis was categorized using BMRC (stages I-III), BMRC-MV (I-IV [MV patients were grouped as stage IV]), and BMRC-HC (I-IV [BMRC stage III patients with hydrocephalus were grouped as stage IV]). Haydarpasa Meningitis Severity Index scoring was categorized as < 6 and ≥ 6. The outcome was defined at 6 months using the modified Rankin Scale (mRS) as death, poor (mRS score > 2), or good (mRS score ≤ 2). Forty-nine (25%) patients died. BMRC-mechanical ventilation stage IV had the highest predictive value for defining death, with a sensitivity of 88% and a specificity of 86%. About 81.7% of surviving patients had a good outcome at 6 months. BMRC-mechanical ventilation stages I-III had the highest predictive value for defining good outcome, with a sensitivity of 93% and a specificity of 61%. In TBM, BMRC-MV staging has the best predictive value for defining death and disability.