Evaluation of Microbiological and Neuroimaging Diagnostic Modalities in Tuberculous Meningitis in Children: A Prospective Observational Study from Rural India

BACKGROUND: Tuberculous meningitis (TBM) remains a leading cause of morbidity and mortality in children, particularly in endemic regions. Early diagnosis is crucial for optimal outcomes, yet remains challenging due to nonspecific clinical presentations and limited diagnostic sensitivity. OBJECTIVE: To evaluate the diagnostic utility of various microbiological and neuroimaging modalities in clinically suspected cases of pediatric TBM and classify cases according to the established diagnostic criteria. MATERIALS AND METHODS: A prospective observational study was conducted at the department of pediatrics of a rural tertiary care center in North India. Fifty children aged 6 months-15 years with suspected TBM were enrolled. All participants underwent comprehensive clinical evaluation, cerebrospinal fluid (CSF) analysis including cartridge-based nucleic acid amplification test (CBNAAT), adenosine deaminase (ADA) estimation, contrast-enhanced computed tomography imaging, and chest radiography. Cases were classified using the Marais diagnostic scoring system. RESULTS: The study population had a median age of 3.2 years with female predominance (58%). All patients presented with fever, while vomiting (92%), irritability (82%), altered sensorium (78%), and seizures (72%) were other common manifestations. 68% of patients presented in advanced British Medical Research Council (BMRC) stages (II-III). CSF analysis revealed lymphocytic predominance in 52% and elevated protein (40-500 mg/dL) in 94% of cases. CBNAAT was positive in 18% of patients, with rifampicin resistance detected in 11% of positive cases. Elevated CSF-ADA (>10 U/L) was found in 42% of all cases and 89% of definite TBM cases. Neuroimaging abnormalities were present in 90% of patients, with hydrocephalus being the most common finding (50%), followed by basal exudates and meningeal enhancement (38%). Mortality was significantly associated with advanced BMRC staging, with 100% fatality in Stage III patients. CONCLUSION: Neuroimaging demonstrated the highest sensitivity for TBM diagnosis in children. While CBNAAT provided definitive diagnosis with high specificity, its sensitivity remained limited. A multimodal diagnostic approach incorporating clinical assessment and CSF analysis including ADA, CBNAAT, and neuroimaging is essential for optimal diagnostic accuracy in pediatric TBM.