Nontuberculous mycobacterial meningitis: report of two cases and review

Nontuberculous mycobacterial meningitis (NTMM) is still a rare disease despite the increase in the number of cases of disseminated mycobacterial infection related to the AIDS epidemic. Moreover, there are doubts as to the clinical relevance of the isolation of mycobacteria other than Mycobacterium tuberculosis from cerebrospinal fluid. After analyzing the clinical and pathological data, we classified the cases of NTMM into three groups: definitive (28 cases), probable (19), and doubtful (5). We found that Mycobacterium avium is the most commonly isolated species (60% of cases). M. avium meningitis presents as a disseminated disease, is usually related to serious underlying conditions (mainly immunosuppression), and is associated with a death rate that approaches 70%. Mycobacterium fortuitum meningitis is associated with previous neurosurgery or back trauma; the prognosis for this infection is better when the concomitant abscesses are drained. The clinical characteristics of Mycobacterium kansasii meningitis are similar to those of M. tuberculosis meningitis, but the mortality related to M. kansasii meningitis is high despite appropriate antibiotic treatment. Herein, we present two cases of NTMM that occurred at our center, and we review 50 additional cases reported in the English-language literature.