Isolated leptomeningeal angiomatosis in Sturge-weber syndrome type III: A case report with distinctive neuroimaging features

Sturge-Weber syndrome type III (SWS-III) is the rarest variant of SWS, characterized by isolated leptomeningeal angiomatosis without cutaneous or ophthalmological manifestations. We report the case of an 11-year-old female who developed drug-resistant epilepsy at 18 months of age and mild left hemiparesis. Despite multiple anticonvulsant medications, seizures remained poorly controlled. Brain imaging revealed characteristic findings of right cerebral hemihypotrophy, cortical calcifications, and leptomeningeal enhancement without facial port-wine stain or ophthalmological involvement. These distinctive radiological features led to the diagnosis of SWS-III. This case highlights the crucial role of neuroimaging in diagnosing SWS-III, where external clinical markers are absent. Recognition of specific radiological patterns is essential for accurate diagnosis and appropriate management.