Treatment of Central Nervous System Tuberculosis

Initial Intensive Phase

The British Thoracic Society recommends a four-drug regimen for the initial 2 months of treatment, including rifampin, isoniazid, pyrazinamide, and a fourth drug (ethambutol, streptomycin, or ethionamide), for a total duration of 12 months 1, 2, 3
Ethambutol should be used with caution in unconscious patients due to the risk of optic neuritis, and alternatives such as streptomycin or ethionamide should be considered 1, 2, 3

The British Thoracic Society guidelines note that isoniazid, pyrazinamide, and prothionamide/ethionamide penetrate well into cerebrospinal fluid, while rifampin penetrates less well 1, 2, 3
Streptomycin and ethambutol only achieve adequate CSF concentrations when meninges are inflamed during the early treatment phase 1, 2, 3

The continuation phase should consist of a two-drug regimen of rifampin and isoniazid for 10 months, rather than the standard 4 months for pulmonary TB, to prevent relapse 1, 2, 3

The British Thoracic Society strongly recommends corticosteroids for more severe CNS tuberculosis (stages II and III disease), with a dose of prednisolone 60 mg/day initially, tapering over several weeks 1, 2, 3, 4
Corticosteroids decrease neurologic sequelae and improve outcomes, especially when administered early in the disease course 1, 2, 3, 4

Pyridoxine (vitamin B6) supplementation of 25-50 mg daily should be administered to all patients receiving isoniazid to prevent peripheral and central nervous system side effects 5

In HIV co-infection, the same 12-month regimen should be used, with consideration of significant drug interactions between rifampin and protease inhibitors/NNRTIs 5, 6
In pediatric CNS TB, children should receive a minimum of 12 months of therapy, with dosing adjusted according to weight 1, 2

Baseline hepatic function tests are essential, especially in HIV-infected patients, pregnant women, and those with liver disease or alcohol use 4

Never use a 6-month regimen for CNS tuberculosis, as CNS disease requires 12 months minimum 1, 2, 3
Never use intermittent dosing (twice or thrice weekly) for CNS TB, as daily administration is mandatory 4
Do not omit the fourth drug in the initial phase, even in low-resistance settings, as CNS disease is too severe to risk inadequate treatment 1, 2, 3
Do not use ethambutol as the fourth drug in unconscious patients without considering alternatives, as visual monitoring is impossible 1, 2, 3
Do not forget corticosteroids in stages II and III disease, as they significantly reduce mortality and neurologic sequelae 1, 2, 3, 4