Intrathecal Isoniazid and Dexamethasone Therapy May Improve Outcomes in Patients with Tuberculous Meningitis: A Two-Center Retrospective Cohort Study

Objective To evaluate the effect of intrathecal (IT) administration of anti-tuberculosis agents on functional outcomes in patients with tuberculous meningitis (TBM), and to explore its potential as a strategy to overcome the blood-brain barrier. Methods We retrospectively analyzed TBM patients admitted between 2012 and 2023 at Hangzhou Red Cross Hospital and Shanghai Public Health Clinical Center. Clinical data were collected during hospitalization, and functional outcomes were assessed at 3-6 months after discharge using the modified Rankin Scale (mRS). Propensity score matching (PSM) was applied to balance baseline characteristics between patients who received IT therapy and those who did not. Treatment effects were compared using the Mann-Whitney U test. Results A total of 533 patients with TBM were included. After PSM, 72 patients receiving IT therapy were compared with 121 matched controls. IT therapy was associated with significantly lower mRS scores at discharge compared with controls (P = 0.0012), suggesting that it may improve functional outcomes. Conclusions Intrathecal administration of isoniazid and dexamethasone may improve functional prognosis in TBM patients. These findings highlight IT therapy as a promising approach to circumvent the blood-brain barrier and warrant validation in multicenter randomized controlled trials.