Tuberculous meningitis (TBM): Clinical and laboratory findings

The diagnosis of TBM is still a challenge because of the difficulty of demonstrating M. tuberculosis (Mtb) in the cerebrospinal fluid (CSF). Objective: To evaluate the clinical and laboratory findings of TBM. Methods: From 1993 to 1996, all cases of TBM with one of the following criteria were included: (1) CSF Mtb isolation, (2) CSF smear positive for acid-fast bacilli (AFB) plus polymerase chain reaction (PCR) for Mtb, (3) PCR for Mtb, (4) CSF smear positive for AFB or histologic identification for AFB. Results: 17 patients with TBM were identified. Nine male and 8 female, with a mean age of 23 17 yr. Mean duration of signs and symptoms before hospitalization was 13 11 days. The clinical stages of TBM on admission included stage II in 76% and stage III in 24%. Eleven patients had definite TBM. The diagnosis was confirmed by CSF Mtb isolation in 8 (47%) and by CSF smear positive for AFB plus PCR in 3 (18%). Six patients had probable TBM, 5 (29%) with CSF smear positive for AFB and only one case the diagnosis was confirmed by histologic identification. Mean value of leucocytes in CSF was 245 193 mm3 and protein mean value of 527 627 mg/dL. Hyponatremia was present in 64%, hydrocephalus in 47%, focal brain abnormalities in 23% and ventriculoperitoneal shunts were performed in 6. Four primary drug and steroids were used to treat the majority of patients. Overall, 33% of isolates were resistant to isoniazid and streptomyycin. Eight patients died and 7 of survivors are left with permanent neurologic handicaps. Conclusion: Subacute meningitis and clinical stage II were the most common clinical presentation of TBM. Pleocytosis and increased protein in CSF were frequent laboratory findings. The mortality was high