SMART syndrome: retrospective review of a rare delayed complication of radiation

Tarun D. Singh, Mania Hajeb, Alejandro A. Rabinstein, Amy C. Kunchok, Sean J. Pittock, Karl N. Krecke, John D. Bartleson, David F. Black

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Background: SMART (stroke-like migraine attacks after radiation therapy) is a rare, delayed complication of brain radiation. In this study, we wanted to review the spectrum of symptoms, neuroradiological findings, autoimmune status, and outcomes in SMART syndrome patients. Methods: We conducted a retrospective cohort study of all consecutive adult patients (≥18 years) diagnosed with SMART syndrome at Mayo Clinic, Rochester between January 1995 and December 2018. Results: We identified 25 unique patients with SMART syndrome and a total of 31 episodes and 15 (60%) patients were male. The median age at onset was 46 (interquartile range [IQR] 43–55) years and the median latency of onset after the initial radiation was 21.6 (IQR 14.4–28.2) years. Magnetic resonance imaging (MRI) showed gyral edema and enhancement in all cases with the temporal (25, 80.6%) and parietal (23, 74.2%) lobes being the most commonly affected. The median follow-up of the patients in our cohort was 10 (IQR 6–32) weeks. On univariate analysis, factors associated with an increased risk of recurrent SMART episodes were female gender (odds ratio [OR] 8.1, 95% confidence interval [95% CI] 1.1–52.6, p = 0.019) and absence of electrographic seizure discharges during initial symptoms (OR 7.4, 95% CI 1.1–45.9, p = 0.032). We could not identify an autoimmune etiology. Longer duration of symptoms (>10 weeks) correlated with an older age (p = 0.049), temporal lobe involvement (p < 0.001), and diffusion restriction (p = 0.043). Conclusions: SMART is a syndrome with characteristic imaging findings and clinical features. Incomplete recovery by 10 weeks occurred in one-third of individuals and was associated with older age, temporal lobe involvement, and restricted diffusion on MRI.

Original languageEnglish (US)
Pages (from-to)1316-1323
Number of pages8
JournalEuropean Journal of Neurology
Issue number4
StatePublished - Apr 2021


  • SMART syndrome
  • imaging
  • migraine
  • prognosis
  • recurrence
  • seizure

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology


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