A Rare Case of Diffuse Leptomeningeal and Cortical Enhancement Secondary to Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome in a Patient With a History of Childhood Medulloblastoma.

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare complication of craniospinal irradiation (CSI). Patients commonly present with headaches, seizures, and paroxysmal focal neurological deficits. There is a dearth of studies reported in the literature with an estimated fewer than 100 cases described since it was initially defined in the mid-1990s. The authors present the case of a 23-year-old patient with a history of childhood medulloblastoma and prior ventriculoperitoneal shunt (VPS), chemotherapy, and CSI who presented with headaches and new-onset seizures. Magnetic resonance imaging (MRI) of the brain showed diffuse left temporoparietal and occipital leptomeningeal and cortical enhancement. However, cerebrospinal fluid (CSF) analysis was unremarkable for neoplastic, infectious, or inflammatory etiology. Initiation of systemic steroid therapy resulted in drastic improvement of the patient's symptoms and prompted antiepileptic drug (AED) wean and persistent resolution of leptomeningeal and cortical contrast enhancement on brain MRI. When evaluating MRI evidence of leptomeningeal enhancement, neurosurgeons should consider SMART syndrome in the differential diagnosis, especially when extensive workup rules out more common causes of this finding such as leptomeningeal disease (LMD). Proper identification of SMART syndrome can lead to timely treatment, avoidance of invasive procedures such as tissue biopsy, and improved clinical outcomes.