Tuberculous Brain_abscess

 Tuberculous brain abscess (TBA) is a rare but serious condition. It resembles a pyogenic brain abscess clinically and radiologically and poses a problem in diagnosis and treatment. A final diagnosis is established by smear or culture demonstration of acid fast bacilli (AFB) within the abscess. Here, we report four such cases in our five-year study on brain abscesses, along with the different diagnostic modalities used. A total of 75 brain abscess pus specimens were collected during neurosurgery, either by burr hole or by craniotomy. These specimens were further subjected to Gram stain, Ziehl-Neelsen (ZN) stain, and conventional microbiological culture. Only those cases which showed presence of AFB on ZN stain along with the growth of Mycobacterium tuberculosis were considered as TBAs. Such TBA cases were further presented along with their In vitro Proton Magnetic Resonance (MR) Spectroscopic findings. Tuberculous brain abscess (TBA) is a rarely reported form of central nervous system (CNS) tuberculosis. TBA is a focal collection of pus containing abundant acid fast bacilli (AFB) surrounded by a dense capsule consisting of vascular granulation tissue. TBA always poses a diagnostic dilemma as they are difficult to differentiate from pyogenic brain abscesses, tuberculous meningitis, and tuberculoma on the basis of clinical, laboratory, and roentgenographic information. Whitener, in his excellent review, had laid down the diagnostic criteria for TBA. The present study reports four cases of TBA along with comparative analysis of other TBA cases from the available literature.