Awareness for SMART Syndrome (Stroke-Like Migraine Attacks After Radiation Therapy), a Rare and Delayed Complication of Cranial Irradiation: A Case Report with Literature Review
Shiv Jha1, Monika Pandit2, Binod Mehta3, Jeremey Wong1, Eric Mariuma1
1Neurology, Montefiore Medical Center/ Albert Einstein College of Medicine, 2Radiology, BP Koirala Health Sciences, 3St. Francis Medical Center
Background:
SMART syndrome is a rare, delayed complication of cranial radiation therapy, often presenting years later with triad of migraines, stroke-like deficits, and seizures. The diagnosis is challenging, as symptoms may mimic tumor recurrence, radiation necrosis, or stroke. Here, we report a case that developed decades after cranial irradiation.
Results:
69-year-old woman with history of Astrocytoma resection and radiation therapy 35 years ago presented with a fall, left-hemianopsia, and worsening of left-hemiparesis. She eventually developed focal seizure arising from the Left temporoparietal region in video-EEG and intermittent migrainous-headache with episodic worsening of hemiparesis, initial workup including MRI brain, whole spine, and CSF analysis was negative for infectious/autoimmune/paraneoplastic causes. She was empirically treated with antibiotics/antiviral and IVIG for autoimmune-encephalitis in the interval without adequate response.
A repeat brain MRI after four days of presentation, performed due to worsening seizures and new migraine, revealed FLAIR/T2 hyperintensity in the right parieto-temporo-occipital region, with cortical gyri-form enhancement and diffusion restriction in the previously irradiated area which had fully reversed on two weeks follow up imaging. Her symptoms resolved with conservative management (analgesics & levetiracetam), and she was discharged with consideration of verapamil.
Conclusions:
Our case demonstrates a rare occurrence of SMART-syndrome initially thought to be todd’s paresis, tumor recurrence, or autoimmune encephalitis. SMART-syndrome, though rare, should be included in the differential diagnosis with history of cerebral irradiation, even decades later (range from 1 to 37 years, average 20-years post-radiation). The underlying mechanism unknown but believed to be due to radiation-induced neuronal, mitochondrial, or Blood-brain-barrier/endothelial injury causing neuronal hyper-excitability and cortical-spreading-depression manifesting as seizures, migraine, and paroxysmal focal deficits/stroke-like symptoms (aphasia, hemianopsia, hemi-sensory loss, hemiparesis, or neglect), with cortical gyri-form enhancement on MR imaging.
Awareness and early recognition of SMART-syndrome can help prevent unnecessarily extensive evaluations and invasive procedures such as brain biopsies for suspected tumor recurrence.
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