Characteristics of acute ischemic stroke and unusual aura in patients with migraine with aura

BackgroundSometimes migraine aura changes from attack to attack, raising the question of whether the change is heralding an ischemic stroke or an unusual aura. Differentiating unusual migraine aura from the onset of an acute ischemic stroke in patients with migraine with aura (MwA) can be challenging.ObjectiveThe aim of this cohort study was to assess clinical characteristics that help distinguish between MwA and minor stroke in patients with a previous history of MwA who presented with suspicion of stroke.MethodsWe interviewed patients with MwA and ischemic stroke (MwA + IS) and patients with MwA and unusual aura, but without ischemic stroke (MwA - IS) from a tertiary hospital using a structured questionnaire. We assessed how symptoms of ischemic stroke or unusual aura differed from usual, that is, the typical aura in each patient. Stroke or exclusion of stroke was verified by multimodal magnetic resonance imaging.ResultsSeventeen patients with MwA + IS and twelve patients with MwA - IS were included. New focal neurological symptoms (13/17 [76%] vs. 3/12 [25%]), change of the first symptom (10/17 [59%] vs. 1/12 [8%]), and absence of headache (6/15 [40%] vs. 2/10 [20%]) were more often reported during ischemic stroke. The physical examination was normal in 8/17 (47%) MwA + IS and in 6/12 (50%) MwA - IS patients. In 5/17 (29%) patients with MwA + IS, there were unequivocal physical signs suggestive of stroke such as persistent visual loss, ataxia, or paresis.ConclusionThere are clues from the history that might help identify stroke in patients with MwA with changed aura symptoms. These might be particularly useful in patients presenting without physical findings suggestive of stroke. Sometimes migraine aura symptoms change from attack to attack, raising the question of whether the change is heralding an ischemic stroke or simply an unusual aura. In patients with migraine with aura, we compared symptoms of unusual aura in patients who had ischemic stroke on imaging versus those who did not. Patients who had ischemic stroke were more likely to report new neurological symptoms (such as visual, sensory, speech, or motor symptoms), change of first occurring symptom (e.g., sensory instead of the usual visual), and absence of headache during the attack.