Evaluation of prognostic factors in medically treated patients of spinal tuberculosis

This study was aimed to determine the prognostic factors in medically treated patients of spinal tuberculosis. In this longitudinal observational study, from July 2010 to December 2011, 70 consecutive patients (40 males and 30 females) spinal tuberculosis were enrolled. Diagnosis of spinal tuberculosis was based on characteristic clinical and neuroimaging features. Diagnosis was histopathologically and/or bacteriologically verified. Patients received antituberculous treatment as per World Health Organization guidelines and were followed for 6 months. Disability was evaluated with modified Barthel index (MBI). Outcome was defined as good (MBI > 12) and poor (MBI ≤ 12). Various clinical and neuroimaging parameters, likely to affect the outcome, were analyzed using univariate and multivariate analysis. After 6 months, 45 patients had a good outcome, while 25 patients had a poor outcome. On univariate analysis, duration of illness >6 months (OR 0.062, CI 0.018-0.212), bladder involvement (OR 0.102, CI 0.033-0.317), spinal deformity (OR 0.050, CI 0.013-0.196), spastic paraparesis (OR 0.572, CI 0.190-1.723), and flexor spasms (OR 0.077, CI 0.021-0.280) were found as important clinical predictors of poor outcome. Involvement of more than 2 vertebrae (OR 0.095, CI 0.028-0.328), complete collapse (OR 0.072, CI 0.022-0.241), cord compression (OR 0.025, CI 0.003-0.204), spinal extension of the abscess (OR 0.044, CI 0.005-0.350), and thick/septate abscess wall (OR 0.062, CI 0.016-0.240) were the neuroimaging parameters associated with poor prognosis. However, on multivariate analysis, duration of illness >6 months (Exp-b 0.086, CI 0.019-0.378), cord compression (Exp-b 0.035, CI 0.003-0348), and spinal extension of the abscess (Exp-b 0.109, CI 0.017-0.91) were significant. Medical management results in clinical improvement in a majority of the patients of spinal tuberculosis. Duration of illness >6 months, cord compression, and spinal extension of abscess are associated with poor outcome.