Forty years of Tuberculous meningitis: The new face of an old enemy.

Background: Tuberculous meningitis (TBM) occurs in 1-5% of cases of tuberculosis. Without early treatment, mortality and permanent disability rates are high.

Methods: A retrospective study performed at a tertiary hospital in Madrid (Spain) to describe clinical, diagnostic, and therapeutic aspects of TBM and analyze epidemiological trends over forty years, divided into two intervals (1979-1998 and 1999-2018).

Results: Overall, TBM was diagnosed in 65 patients (1.8% of new tuberculosis diagnoses), 48 in the first period and 17 in the second one. Median age at diagnosis increased from 38.5 to 77 years (p = 0.003). The proportion of non-HIV immunosuppressed patients increased (from 2.1% to 29.4%, p < 0.001), while the percentage of patients with a history of drug-abuse decreased (from 33.3% to 5.9%, p = 0.027). The median time between the onset of neurological symptoms and lumbar puncture increased from seven to 15 days (p = 0.040). The time between the onset of symptoms and the initiation of tuberculostatic treatment also increased from eleven to 18 days (p = 0.555). Results from image, biochemical, and microbiological tests showed no differences between both periods. A decreasing trend was observed in survival rates at 1-week (from 97.9% to 64.7%, p < 0.001), 1-month (from 91.7% to 58.8%, p = 0.002) and 1-year (from 85.4% to 47.1%, p = 0.002) after TBM diagnosis.

Conclusions: The profile of patients diagnosed with TBM has changed from a young HIV-infected patient with a history of drug addiction to an elderly patient with non-HIV immunosuppression. Diagnosis and start of treatment both experienced a noticeable delay in the second period, which could help explain the increase in mortality observed across the two periods.