NCMP-26. STROKE-LIKE MIGRAINE ATTACKS AFTER RADIATION THERAPY SYNDROME IN CHILDREN WITH CANCER

Abstract

BACKGROUND: Stroke-like migraine attacks after radiation therapy (SMART) syndrome is an infrequently described symptom complex of transient neurologic deficits, headache and abnormal cortical contrast enhancement on brain MRI. Pathophysiology is unclear, but exposure to cranial radiation (RT) is a sine qua non. METHODS: We completed a single institution retrospective case series composed of five children with a diagnosis of cancer, history of cranial RT, and episodes of transient neurologic deficits. RESULTS: Five children (2 males, 3 females) fulfilled diagnostic criteria. Tumors were in the posterior fossa (3 medulloblastoma, 1 atypical teratoid rhabdoid tumor) and temporal lobe (1 pleomorphic xanthoastrocytoma). Median age at diagnosis was 9.4 years (range 5.1-14.7). All patients had complete resection, followed by adjuvant 54 Gy focal RT (N=1) or 36 Gy CSI followed by a cone-down to 54 Gy (N=4), and chemotherapy. Median body mass index was 17.1 (range 14 to 30). Median time from the end of RT to first transient neurologic deficit was one year (range 0.7-12.1). Presenting symptoms included gradual development of unilateral weakness (N=4), non-fluent dysphasia (N=1), somnolence (N=1), and headaches (N=3). Neurologic deficits resolved within 30 minutes to 10 days. Transient cortical enhancement was confirmed on MRI in two patients, two had a normal brain MRI, and one had no MRI obtained. Two children had a single and three had multiple episodes over the next few months. Topiramate was successfully used in one and failed along with levetiracetam in another. Two children with protracted symptoms responded to high dose intravenous methyl prednisone for three days followed by 2 weeks of oral taper. Symptoms ultimately resolved in all patients. CONCLUSION: SMART syndrome is a rare disorder characterized by slow development of neurologic deficits with variable occurrence of abnormal cortical contrast enhancement. The use of anti-epileptics and/or steroids may improve symptoms and speed resolution.