Background
Tuberculous meningitis (TBM) frequently presents with hyponatremia. However, its relation with disease severity and patient outcomes remains poorly understood.
Methods
In a prospective cohort study of adult TBM patients in Indonesia, we investigated the prevalence and prognostic significance of hyponatremia, defined as moderate (120-130 mEq/L) or severe (<120 mEq/L). All patients received anti-tuberculous therapy and corticosteroids. Patients were followed for mortality during and after hospitalization for 365 days.
Results
Among 864 adult TBM patients (median age 30 years, 60.5% male, 14.9% HIV-infected), 750 (86.8%) had hyponatremia, of whom 26% had severe hyponatremia (<120 mEq/L). Severe hyponatremia was associated with male, younger age, a lower Glasgow Coma Scale (GCS), concomitant pulmonary tuberculosis culture-confirmed TBM, higher cerebrospinal fluid (CSF) neutrophil count and protein, lower CSF/blood glucose ratio, anemia, blood leukocytosis, neutrophilia, and lymphopenia (p <0.05). One-year mortality was 46.5 % and associated with older age, HIV infection, lower GCS at presentation, markers of neurological severity, fever, and thrombocytosis. Severe hyponatremia was associated with increased mortality in univariate analysis in HIV-negative patients, but not in multivariate analysis, and not in HIV-positive patients.
Conclusions
Hyponatremia is common in patients with TBM and is associated with clinical severity, CSF and blood inflammation, and death. However, in our setting, hyponatremia does not independently contribute to increased mortality, and aggressive correction of hyponatremia is therefore unlikely to improve prognosis.
