Role of Magnetic Resonance Imaging and Spinal Tap in Early Diagnosis of Tuberculous Meningitis

Background: Tuberculous meningitis (TBM) is difficult to diagnose in early stages due to nonspecific symptoms. There should be high index of suspicion to diagnose TBM at an early stage. The objective of the study was to find out the role of magnetic resonance imaging (MRI) and spinal tap in early diagnosis of tuberculous meningitis. Material and Methods: A cross sectional study was conducted from July 2015 till July 2018 at Neuromedicine ward, Jinnah Postgraduate Medical Centre (JPMC), Karachi. All patients above 12 year of age, both male and female with nonspecific symptoms like headache, malaise and drowsiness or suspicion of TBM (stage I, II, and III according to British Medical Research Council TBM staging criteria) were included in the study. Patients diagnosed with other CNS disease like encephalitis, malaria and acute bacterial meningitis were excluded. Magnetic Resonance Imaging (MRI) of the brain and early spinal tap for cerebrospinal fluid (CSF) analysis were used to diagnose TBM and findings were noted. Results of MRI and CSF analysis were analyzed by SPSS version 24. Results: A total of 110 patients of TBM, with 60 (54.5%) male and 50 (45.5%) female patients were included in the study. Most of the patients belonged to a younger age group of 12-40 years (81.8%), while 18.2% were above 40 years of age. About 90% patients were diagnosed in stage I TBM and 10% in stage II and III. MRI brain findings included meningeal enhancement (60%), hydrocephalus (41.81%) cerebral edema (82.73%), tuberculoma (19%) and infarct (14.5%), respectively. CSF analysis showed low protein in 80%, low glucose in 91.8% and lymphocytic pleocytosis in 97.2%, respectively. Conclusion: Both MRI brain and spinal tap with CSF analysis played a role in the early diagnosis of TBM, which is important to prevent the lethal complications associated with late diagnosis of this disease.