Changing trends of presentation of central nervous system tuberculosis: Relative prevalence of cranial and spinal tuberculosis and drug resistance patterns.

Abstract

Inappropriate use of antituberculosis drugs and a poor compliance has led to an increase in the prevalence of resistant Mycobacterium tuberculosis. The aim of this study was to document the changing trends in clinical presentation and drug resistance in patients with tuberculosis (TB) of the brain and the spine. The authors retrospectively analyzed data from 243 patients admitted in a neurosurgical unit for surgical management of TB of the brain and spine from 2000 to 2013. To establish changes in trends, the patient population was arbitrarily divided into two groups based on their years of admission: 2000-2006 (Group A; n = 121) and 2007-2013 (Group B; n = 122). In the second era (Group B), there were 14.5% more patients with TB spine [from 42/121 (34.7%) in Group A to 60/122 (49.2%) in Group B; P = 0.02] with a corresponding reduction in the proportion of patients with TB brain. The number of cerebrospinal fluid (CSF) diversion procedures remained the same in both the groups, but there was significant reduction in other surgical procedures for patients with TB brain in Group B (P = 0.0004). In patients with TB brain, the culture yield was 10/50 (20%) from tissue and 8/72 (11%) from CSF and there was no significant difference between the groups. In patients with TB spine, the culture yield was higher in Group B patients but was not statistically significant [7/35 (20%) in Group A versus 18/57 (31.6%) in Group B (P = 0.27)]. In Group A, nine patients with TB brain grew Mycobacterium tuberculosis in culture and none was resistant to first-line antituberculosis therapy (ATT), while in Group B, nine patients grew the bacilli and five had resistance to first-line ATT (P = 0.03). Among patients with a positive culture of resistant TB, all had received prior ATT (100% secondary resistance). None of the seven patients with TB spine in Group A with a positive culture had resistant organisms, but in Group B, 5 of 18 (27.8%) with a positive culture had resistant organisms (P = 0.27). Of these, five patients with TB spine with resistance, three of five (60%) patients had secondary resistance, and two of five (40%) patients had primary resistance. Overall, 10 of 27 (37%) patients with a positive culture had resistant organisms in Group B, while none of 16 patients in Group A with a positive culture had resistant organisms (P = 0.007). The most significant finding of our study is an alarming increase in the number of patients with TB brain and spine who have resistant disease (from 0% to 37%) with most of the resistance being secondary in nature. There was an increase in the number of in-patients with spinal TB relative to those with TB brain, though the cause for this is unclear.