Tuberculous meningitis - An update on diagnostic approaches

Abstract

Tuberculous meningitis (TBM) is a severe form of extrapulmonary tuberculosis which causes a devastating morbidity and mortality in adults and children. Even in patients presenting at an early stage of disease, deterioration may occur despite apparently adequate therapy. Diagnosis of TBM is primarily based on clinical diagnosis, neuroimaging abnormalities and cerebrospinal fluid (CSF) changes. Other diagnostic methods are smear examination, mycobacterial culture, serological assays, adenosine deaminase (ADA) assay, interferon-γ release assays (IGRAs) and nucleic acid amplification (NAA) tests that could be helpful in TBM confirmation. However, most of assays have low sensitivity and long time duration to detect tubercle bacilli in TBM cases which could results into increased morbidity and mortality. To reduce the number of morbidity and mortality, early detection of tubercle bacilli is highly crucial so that anti-tuberculous treatment (ATT) should be started at early phase. NAA tests are useful to detect Mycobacterium tuberculosis in CSF samples at early stage. However, NAA tests revealed variable results in diagnosing of TBM. Hence, the conjugation of NAA tests with other diagnostic methods should be used to detect TBM at early stage to achieve high accuracy.