Cerebral tuberculosis among elderly patients with miliary tuberculosis undergoing brain MRI: a retrospective observational study.

OBJECTIVE: To determine the frequency and clinical characteristics of cerebral tuberculosis among elderly patients with miliary tuberculosis undergoing brain magnetic resonance imaging (MRI). METHODS: We retrospectively reviewed 71 consecutive patients with miliary tuberculosis admitted to a Japanese tertiary hospital between 2006 and 2024. Brain MRI was performed in 31 patients (43.7%) at the discretion of attending physicians. RESULTS: Cerebral tuberculosis was clinically and radiologically diagnosed in 19 of 31 patients (61.3%) undergoing MRI. Routine clinical, laboratory, and microbiological findings did not reliably distinguish cerebral involvement. All 19 patients had multiple supratentorial and infratentorial lesions. MRI was preferentially performed in patients with better performance status, lower Sequential Organ Failure Assessment scores, and less dementia, suggesting a selected population. CONCLUSIONS: Cerebral tuberculosis was frequently identified among patients undergoing MRI but was not reliably distinguishable from routine findings. Although this frequency cannot be extrapolated to all patients with miliary tuberculosis, clinically unrecognized cerebral involvement may be more common than generally appreciated. In elderly patients, MRI may be difficult because of poor general condition, dementia, or other age-related limitations. When MRI cannot be performed, possible cerebral involvement should remain a clinical consideration and may be relevant when selecting antituberculous therapy.