The Difference Between Looking and Seeing at 2 am

A 59-year-old man on anticoagulation due to recent diagnoses of cardiomyopathy, valvular disease, and atrial fibrillation presented with sudden onset severe left-sided weakness, neglect, and language disturbance suggesting a right large middle cerebral artery syndrome. Non-contrast CT the brain was normal and while CT angiography of the intracranial vessels revealed an occluded right internal carotid artery, there was surprisingly excellent filling of the right middle cerebral artery via the anterior communicating artery. With further evaluation and using CT perfusion as an additional tool, an unexpected vessel occlusion became apparent, and the patient proceeded to successful mechanical thrombectomy. We discuss several key learning points around variant anatomy, mechanical thrombectomy and the utility of CT perfusion.