It is possible that shorter durations of therapy (e.g., six months) may be sufficient to treat TB meningitis, but no clinical trial has addressed this issue. The CSF of patients with treated TB meningitis is commonly abnormal even at 12 months; the rate of resolution of the abnormality bears no correlation with clinical progress or outcome, and is not an indication for extending or repeating treatment; repeated sampling of CSF by lumbar puncture to monitor treatment progress should therefore not be done.