DOWN TO THE GROUND ZERO: PERSPECTIVE FROM TISSUE DIAGNOSIS IN NEUROLOGICAL TB

BACKGROUND/AIM Central nervous system tuberculosis (CNS-TB), a severe form of extrapulmonary tuberculosis presents with non specific symptom leading to delayed diagnosis and increased morbidity. This study compares different modalities of diagnosis of CNS-TB [Multiplex real-time PCR/ GeneXpert, TB culture, Ziehl-Neelsen staining( Z-N staining) and histopathology].

METHOD This is a cross sectional observational study conducted in the Department of Neuropathology from October 2016 to May 2019. Total 128 brain and spinal cases which were clinically suggestive of TB and operated were evaluated.

RESULT Granuloma, giant cell and necrosis were less evident in spinal TB compared to brain. GeneXpert and culture positivity were higher(100%) in tissue having poorly formed granuloma compared to well formed granuloma. Z-N stain has poor sensitivity (around 32%). Compared to culture GeneXpert was 100% sensitive and 96% specific in brain TB( detected from tissue) and 87% and 89% in spinal TB respectively.

CONCLUSION Combined together all these modalities provide a wholistic approach so that not a single case of tuberculosis is missed.