Abstract
Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a symptom
complex of transient neurological deficits, headache, and abnormal cortical contrast
enhancement on brain MRI. Pathophysiology is unclear, but exposure to cranial radiation
(RT) is a sine qua non. We report five children with SMART syndrome treated with RT
therapy for medulloblastoma (n = 3), atypical teratoid rhabdoid tumor (n = 1), and pleomorphic xanthoastrocytoma (n = 1). Median age at tumor diagnosis was 9.4 years (range 5.1–14.7). Median follow-up
from cancer diagnosis was 3.1 years (range 1.4–12.9). All patients had 54 Gy focal
RT treatment and medulloblastoma children had additional 36 Gy craniospinal irradiation.
Median time from the end of RT to first transient neurological deficit was 1 year
(range 0.7–12.1). The median follow-up since first SMART episode was 0.6 years (range
0.3–2.6). Presenting symptoms included the gradual development of unilateral weakness
(n = 4), non-fluent dysphasia (n = 1), somnolence (n = 1), and headaches (n = 3). Neurological deficits resolved within 30 minutes to 10 days. Transient cortical
enhancement on magnetic resonance imaging (MRI) was confirmed in two children and
was absent in the other three. Two children had a single and three had multiple episodes
over the next few months. Two children with protracted symptoms responded to 3 days
treatment with high dose intravenous methylprednisolone. Symptoms ultimately resolved
in all patients. SMART syndrome is a rare disorder characterized by slow evolution
of neurological deficits with variable abnormal cortical contrast enhancement. The
use of steroids may improve symptoms and speed resolution.
Keywords
SMART syndrome - children - treatment - imaging
