Extra-central nervous system tuberculosis in HIV-uninfected patients of tuberculous meningitis: A prospective evaluation.

OBJECTIVE

Disseminated tuberculosis is characterized with involvement of two or more non-contiguous sites. In this work we evaluated patients of tuberculous meningitis for possible extra-central nervous system tuberculosis.

METHOD: This prospective observational study was performed at a tertiary care institute in Northern India. We included consecutive HIV-uninfected cases of TBM. Patients were evaluated for extra-central nervous system (CNS) tuberculosis. We focussed on peripheral lymph nodes, chest, abdomen, and spinal involvement. All patients were subjected to MRI brain and spine. Patients were also subjected to CT thorax and abdomen. Enlarged lymph nodes, if present, were biopsied. Ascitic and pleural fluid were subjected to biochemical, cellular analysis as well as cartridge-based nucleic acid amplification test (CBNAAT) for detection of Mycobacterium tuberculosis and rifampicin resistance.

RESULTS

We enrolled 110 patients of TBM. After cerebrospinal fluid examination alone, 14 (12.7%) patients had microbiologically-confirmed TBM. After planned work-up for extra CNS tuberculosis, 5 additional cases were microbiologically confirmed. Similarly, before work-up for extra CNS tuberculosis, 29 (26.4%) patients were categorized as probable TBM. The number of probable cases increased to 72 (65.5%) (P<0.001) with identification of tuberculosis elsewhere. Lung (83.6%) was the most involved site. Abdominal tuberculosis was noted in 29 (26.4%) patients. On imaging spine, 17 (15.5%) patients demonstrated presence of spinal tuberculous. Lymph adenopathy recorded in 2 cases. Lymph node biopsy revealed tuberculous granuloma in both the cases. All 7 patients, who died, had disseminated tuberculosis.

CONCLUSION

Extra CNS tuberculous involvement is common in TBM. Search for extra CNS tuberculous enables upgrading diagnostic accuracy.