Setting: Tuberculous meningitis (TBM) has high morbidity and mortality. Demonstration of tubercle bacilli in cerebrospinal fluid (CSF), the only reliable method of diagnosis, is time consuming and has a low yield. Early diagnosis and treatment are of utmost importance for favourable outcome. Objective: The study was conceived to define easy to use criteria. Methods: A set of criteria using clinical features, CSF examination and computed tomography (CT) findings were defined. 76 patients suspected of having TBM were divided into definite, highly probable, probable and possible TBM based on the criteria. The validity of criteria was tested using information from bacterial isolation, polymerase chain reaction (PCR) test for tuberculosis, response to treatment and autopsy. Results: PCR was positive in over 75% of patients in the highly probable and probable groups. 91% of patients with highly probable and 66% with probable TBM improved on antituberculosis therapy. Conclusion: The criteria are reliable in making early diagnosis of TBM.
