Focal dystonia and ataxic hemiparesis as the initial presentation of a thalamic tuberculoma: A diagnostic challenge in an immunocompetent pediatric patient

BACKGROUND: Central nervous system (CNS) tuberculomas are rare and account for approximately 1% of all tuberculosis (TB) cases. These intracranial lesions are more commonly observed in immunocompromised individuals, often as part of disseminated miliary TB or after latent infection reactivation. This case report presents the occurrence of a thalamic tuberculoma in an immunocompetent girl. CASE DESCRIPTION: An 11-year-old girl presented with a 3-month history of progressive right-sided ataxic hemiparesis, hand dystonia/thalamic hand, and headache. There was only a mildly elevated erythrocyte sedimentation rate (25 mm/h.), and her remaining biochemistry and vitals were unremarkable. Magnetic resonance imaging (MRI) brain revealed an ill-defined intra-axial heterogeneous lobulated lesion with crenated margins involving the thalamus and the posterior limb of the internal capsule with significant vasogenic edema. Given the clinical picture, the working diagnosis was a high-grade brain tumor. Due to the absence of a viable operative corridor for a meaningful resection and the diagnostic uncertainty, a stereotactic biopsy was performed, and histopathological analysis confirmed the presence of granulomas consistent with TB. A human immunodeficiency virus test (negative) and interferon-gamma release assay (positive) were then obtained. The patient was commenced on a regimen of anti-TB drugs with a tapering steroid dose. At 8 months, her most recent MRI showed a significant reduction in the size of her tuberculoma, and there is a complete resolution of her hand dystonia and hemiparesis to allow for independence in her activities of daily living. CONCLUSION: This report emphasizes the importance of considering causes other than degenerative, vascular, or neoplasms in patients with hemiparesis with dystonia. CNS tuberculomas can present as such without prior history or specific clinical symptoms of TB, making them a diagnostic challenge. In cases with such uncertainty regarding the nature of an intracranial lesion and the role of resection, a stereotactic biopsy is invaluable.