Malignant middle cerebral artery infarction revealing atrial fibrillation: A Multimodal imaging case of M1 occlusion treated with decompressive craniectomy.

We report the case of a 70-year-old woman with poorly controlled hypertension who presented with acute left-sided hemiplegia and altered consciousness with a delay of approximately 48 hours from symptom onset.

Electrocardiography revealed previously undiagnosed atrial fibrillation with rapid ventricular response.

Multimodal magnetic resonance imaging confirmed a large cortico-subcortical infarction involving more than 50% of the right middle cerebral artery territory, with marked diffusion restriction and no diffusion-FLAIR mismatch, indicating a completed infarction.

MR angiography demonstrated occlusion of the M1 segment of the right middle cerebral artery.