Radionuclide scintigraphy of the brain and ultrasound studies in tubercular meningitis.

The present study was undertaken to assess the usefulness of brain scintigraphy and ultrasound evaluation of changes described in tuberculous meningitis. Brain scans were done with Tc-99m DTPA in 127 cases of tuberculous meningitis (TBM) and ultrasound studies in 41 cases with open anterior fontanelles. The data show that 54/127 (42.5%) of cases had abnormal brain scans, of which 33/54 had cerebrovascular infarcts and 14/54 had tuberculomas, while the remaining cases had either subdural effusions or generalized increased activity. The cerebrovascular infarcts were more frequent in patients with acute onset of TBM with associated hemiplegias. The ultrasound studies indicated that 80% of all cases of TBM had a mild to severe dilatation of the ventricles. About 55% of cases had a dilatation of only the lateral ventricles while the remaining cases had a block of aqueduct or beyond the fourth ventricles. Increased intracranial pressure changes were associated with a higher incidence of severe ventricular dilatation. Noninvasive detection methods in the study of TBM are important not only from the point of view of diagnosis but also to understand and evaluate the pathological changes occurring in vivo during the disease process and to judge the progress and response to treatment. A combination of ultrasound and brain scans offers diagnostic accuracy comparable to CT. Apart from cost, the larger radiation doses resulting from CT studies preclude its routine use in pediatric subjects.