Estimation of cerebrospinal fluid cortisol level in tuberculous meningitis

BACKGROUND: Central nervous system (CNS) involvement in tuberculosis is around 5–10%. Of the various manifestations of CNS tuberculosis, meningitis is the most common (70–80%). Delay in diagnosis and treatment results in significant morbidity and mortality. OBJECTIVE: To study the cerebrospinal fluid (CSF) cortisol levels in tubercular meningitis and compare the levels with controls. METHODS: Cross-sectional, prospective, observational, hospital-based study done in 20 patients of tubercular meningitis, 20 patients of aseptic meningitis (AM) and 25 control subjects without any preexisting neurological disorders who have undergone lumbar puncture for spinal anesthesia. RESULTS: Cortisol was detected in all 40 CSF samples of patients (100%). Mean CSF cortisol level was 8.82, 3.47 and 1.05 in tubercular meningitis, AM and controls, respectively. Mean CSF cortisol level in tubercular meningitis was significantly higher as compared to AM and controls (P < 0.0001). CONCLUSION: Cortisol level estimation in CSF is one of the rapid, relatively inexpensive diagnostic markers in early identification of tubercular meningitis along with CSF findings of elevated proteins, hypoglycorrhachia and lymphocytic pleocytosis. This aids in earlier institution of appropriate treatment and thereby decreasing morbidity and mortality. This is the first study on the estimation of CSF cortisol level in tuberculous meningitis.