Sensitivity to Acute Middle cerebral or intracranial Carotid artery Occlusion in MIGrainers (SMCO-MIG) is a prospective multi-center study to determine if migraine induces a faster infarct growth as assessed by initial multimodal imaging.

Ischemic stroke results from the occlusion of a brain artery by a clot. Early revascularization by thrombolysis and thrombectomy promotes neurological recovery by saving the area of ischemic penumbra. Progression of ischemic stroke is evaluated on multimodal imaging by the "mismatch ratio" between necrotized core and salvageable hypoperfused volumes.

Migraine affects 12% of the population. Although considered as a benign condition, migraine, particularly with aura, is a risk factor for ischemic stroke. Based on pathophysiological hypothesis and the result of one study, which had several limitations, it's suggest that migraine might increase the sensitivity to cerebral ischemia and induce a faster infarct growth.

The main objective of the study is to determine if the mismatch ratio between irreversibly injured and hypoperfused volumes, measured on initial imaging (MRI or CT) during acute ischemia due to occlusion of the middle cerebral artery or the intracranial internal carotid artery, varies according to the migraine status.

A multicentric prospective cohort will be conduct, outcome study. The initial multimodal imaging (MRI or CT) will be acquired routinely using a harmonized protocol in any patient suspected of an acute stroke. All consecutive patients eligible to the study will be included within 7 days of their initial admission, and evaluated with a short questionnaire classifying them as "migrainers" whose status will undergo a detailed validation at 3 months by a migraine expert, and "non-migrainers" whose status will be validated by repeating the short questionnaire at the follow-up visit at 3 months. All radiological data will be analyzed centrally after the end of the recruitment, by investigators blinded to the migraine status.

Inclusion Criteria:

• Males and females, 18 to 75 years old
• Admitted to a stroke unit for an acute ischemic stroke (<12 h)
• Angiography showing M1/M2 or intracranial internal carotid artery occlusion
• MRI or CT acquired <24h from IS onset, using a harmonized protocol enabling calculation of the mismatch

Exclusion Criteria:

• Individual enrolled into another study protocol with a period of exclusion still running at potential inclusion
• Coma, dementia, linguistic problem or aphasia preventing responding to the migraine questionnaire
• Refusal of participation
• Persons under legal protection, guardianship or curatorship

Patients experiencing an anterior circulation brain infarction complicating the occlusion of the internal carotid artery or the first or second segment of the middle cerebral artery and admitted within 12 hours of onset