Objective:
To report a case in which a prolonged migraine aura resulted in diffusion restriction on MRI
Background:
Migraine aura is defined as reversible recurrent attacks of visual, sensory, speech, motor, brainstem, or retinal symptoms that precede headache onset. It can be a mimic of stroke. Three cases of reversible splenial lesions in the setting of migraine with aura (MWA) have been reported, but those cases only had sensory or visual aura. Here, we present a case of a patient with acute onset of both sensory and visual symptoms found to have diffusion restriction in the splenium that subsequently resolved.
Results:
52-year-old female with a history of remote tobacco use and episodic MWA presented for evaluation of acute onset right-sided face and arm numbness lasting minutes. She had preceding typical vision changes that lasted several hours. MRI Brain completed while she had the symptoms showed a punctate focus of diffusion restriction in the left side of the splenium of the corpus callosum with associated T2 hyperintensity on FLAIR. Stroke risk factor workup was unremarkable. Repeat MRI brain three months later showed resolution of the lesion.
Conclusions:
The presumed mechanism of migraine aura in humans has been correlated with cortical spreading depression (CSD). There are no specific imaging findings consistently correlated with it, but there have been a few cases of splenial lesions seen in the setting of migraine aura. The splenium is vulnerable to elevated glutamate levels causing "excitotoxic edema." It is thought that CSD can result in glutamate release and therefore could be a cause of these reversible lesions. Patients with MWA are known to be at a higher risk for stroke. It is unclear if the mechanism leading to the imaging changes correlated with this stroke risk but is a topic for future research.