Stroke-Like Migraine Attacks after Radiation Therapy (SMART) Syndrome Is Not Always Completely Reversible: A Case Series

Abstract

SUMMARY:We retrospectively reviewed clinical and imaging findings in 11 patients with stroke-like migraine attacks after radiation therapy (SMART) syndrome to better understand this disorder previously thought to be reversible. Six men and 5 women had complex bouts of neurologic impairment beginning, on average, 20 years after cerebral irradiation. All had characteristic, unilateral gyriform enhancement on MR imaging that developed within 2-7 days and typically resolved in 2-5 weeks. Unlike prior reports, 45% had incomplete neurologic recovery manifesting as dysphasia, cognitive impairment, or hemiparesis. The remaining 55% recovered completely over an average of 2 months. Three of 11 patients developed cortical laminar necrosis. Brain biopsies in 4 of 11 did not demonstrate a specific pathologic substrate. These additional 11 patients contribute to the understanding of variability in stroke-like migraine attacks after radiation therapy syndrome, which often but not uniformly manifests with headaches and seizures, demonstrates a typical evolution of imaging findings, and may result in permanent neurologic and imaging sequelae. ABBREVIATIONS:SMART ϭ stroke-like migraine attacks after radiation therapy; CLN ϭ cortical laminar necrosis; CJD ϭ Creutzfeldt-Jakob disease; PIPG ϭ

Stroke‐like migraine attacks after radiation therapy: A misnomer?

“…MRI changes in SMART, however, appear to uniformly present with hemispheric confluent gray matter changes that do not respect vascular boundaries. 2 It is possible that these consistently extensive hemispheric MRI changes seen in our SMART patients relate to a preexisting postradiation neuronal injury. 33 Alternatively, the preexisting vasculopathy in SMART may explain imaging findings in 2 ways.…”

“…Three patients had evidence of diffusion restriction, which completely resolved in 2 patients on follow-up (Tables 2 and 4). In Patients 2, 3, 4, and 5, subdural fluid collections were found in conjunction with parenchymal abnormalities that were improved (4), stable (2,3) or resolved (5) on follow-up imaging (Table 4). Acute radiographic abnormalities resolved completely in follow-up MRIs in Patients 1, 3, 5, and 6, whereas the remainder of patients had partial improvement on follow-up ( (presentation 1b), which were otherwise noted to be remarkably similar in radiographic appearance.…”

Investigation of Abscopal and Bystander Effects in Immunocompromised Mice After Exposure to Pencilbeam and Microbeam Synchrotron Radiation

“…Thus, patients with multiple brain metastases are often selected for whole brain radiotherapy (WBRT) simply because it is the only option available. However, the most common problem reported after WBRT are chronic changes in the white matter, which are associated with stroke-like migraines (Kerklaan et al 2011;Black et al 2013;Armstrong et al 2014) , cognitive deficits (Shi et al 2009;Peiffer et al 2014;Forbes et al 2014) and dementia (DeAngelis et al 1989;D'Ambrosio et al 2007;Tallet et al 2012).…”

Susceptibility-weighted imaging in stroke-like migraine attacks after radiation therapy syndrome

“…SMART syndrome is a relatively rare syndrome that has been reported to occur anywhere from 1-35 years after cranial irradiation and may simulate recurrent neoplasm [1][2][3][4][5][6]. The clinical manifestations are migraine-like episodes in tandem with prolonged symptoms referable to a unilateral cortical region, which may include hemiparesis, hemisensory loss, aphasia, visual deficits, seizures, or confusion [1][2][3].…”

“…The migraine-like headache is associated with typical postcontrast MRI findings that consist of transient, diffuse, unilateral cortical gadolinium enhancement of the cerebral gyri within a previous radiation field [2,3]. MRI findings may also occasionally include transient cortical T2WI or FLAIR hyperintensity and diffusion abnormalities [2][3][4][5][6]. Clinical symptoms and MRI findings are often episodic and may recur, but these typically normalize without evidence of marked atrophy and hemorrhagic complications [1][2][3][4].…”