Clinical indicators associated with tuberculous meningitis using multiple correspondence analysis

Tuberculous meningitis (TBM), the most severe extrapulmonary manifestation of Mycobacterium tuberculosis (Mtb) infection, contributes to 5-10 % of global tuberculosis-related mortality. This study aimed to delineate clinical indicators predictive of microbiologically confirmed TBM to facilitate early diagnosis in resource-limited settings.

A retrospective cohort analysis was conducted on 146 TBM cases admitted to Shenzhen Third People's Hospital (2018-2020), undergoing cerebrospinal fluid (CSF) culture and Xpert. Epidemiologic profiles and clinical outcomes were systematically characterized. Multiple correspondence analysis (MCA) adjusted for potential confounders was employed to identify clinical indicators associated with microbiologically confirmed TBM.

Among 146 patients with defined or probable TBM, 80 cases were detected for Mtb in CSF, with undetected in 66 cases. The increase in CSF white cell count was more significant than that in blood. Serum sodium, serum chloride (Cl), CSF glucose, CSF Cl, and CSF to blood glucose ratio in microbiologically confirmed TBM were significantly lower than those in unconfirmed TBM, in addition to having worse nutrition and lower blood lymphocytes. MCA identified diagnostic indicators related to microbiologically confirmed TBM included neck stiffness, decreased blood lymphocyte counts and serum sodium, elevated CSF white cell count, decreased CSF glucose and Cl levels, HIV positivity, severe pulmonary infection, and malnutrition. However, Hypertension and pulmonary tuberculosis were associated with microbiologically unconfirmed TBM.

The clinical indicators identified in this study may assist clinicians in high-tuberculosis-incidence-areas, particularly in regions with limited capacity for CSF microbial culture, to empirically diagnose TBM. When these indicators are abnormal, they may increase the likelihood of detecting microbial evidence in CSF.