Predictors of mortality in CNS tuberculosis: clinical and radiological parameters

Central nervous system tuberculosis (CNS-TB) is a rare but highly lethal form of TB with heterogeneous clinical and radiological features. We evaluated objective clinical grading, CSF indices, and MRI findings associated with in-hospital mortality.

In this single-center retrospective cohort (2010-2023), all consecutive adults with CNS-TB were included (n = 15). Patients were grouped as survivors (n = 6) and non-survivors (n = 9). We extracted BMRC stage, baseline GCS, symptom-to-presentation and symptom-to-treatment durations, CSF cyto-biochemistry and microbiology (culture/PCR), and a standardized MRI checklist (basal exudates, hydrocephalus, ventriculitis, infarcts, tuberculoma/abscess, cranial nerve enhancement, spinal involvement). Treatment protocols (ATT, dexamethasone indications, neurosurgery) were documented. Results are primarily reported as counts/proportions with exploratory effect sizes.

The mortality rate was 60%. Non-survivors were significantly older (57.8 ± 22.8 vs. 29.2 ± 6.9 years; P = 0.029, d = 1.56) and had higher serum AST levels (28.9 ± 6.4 vs. 15.0 ± 2.9 U/L; P = 0.007, d = 2.14). CSF leukocyte count was also significantly elevated in non survivors (P = 0.041, d = 0.95). Cerebral ischemia was present only in non-survivors (56% vs. 0%; P = 0.04, h = 0.98). PCR positivity in non-CSF samples (0% vs. 78%) was significantly associated with mortality (P = 0.007). Other parameters showing moderate to large effect sizes included focal neurological deficits, ventriculitis, and increased CSF opening pressure.

Advanced age, elevated AST levels, increased CSF leukocyte count, cerebral ischemia, and extraparenchymal PCR positivity emerged as major predictors of mortality in CNS-TB. These factors may aid early risk stratification and treatment planning. Larger prospective studies are warranted to validate these findings.