The patient’s last known well was approximately 6 hours prior to coming to the hospital. Baseline NIHSS was 2. The patient had a left facial droop and a weakness of the left triceps. A computed tomography of the head showed no acute abnormality. The patient received no acute intervention due to being outside of the therapeutic window. Further stroke work-up was performed and her MRI Brain and MRA head and neck showed no acute signs of a stroke but did show delayed perfusion to the right cerebral hemisphere alongside brachiocephalic trunk origin occlusion. On imaging in the angiographic phase, there was non-opacification of the brachiocephalic trunk along with the right common carotid artery (CCA), right subclavian artery, and right vertebral artery. The patient was evaluated by vascular surgery who elected to follow-up with her as an outpatient.

Subclavian steal syndrome is a relatively rare vascular condition where stenosis of typically, the left subclavian artery, leads to retrograde flow through the ipsilateral vertebral artery. The equivalent syndrome on the right side of the body presents slightly differently and is less well-documented compared to its left-sided counterpart. Innominate artery steal syndrome is a proximal stenosis of the brachiocephalic trunk. In subclavian steal syndrome, the presenting condition is due to vertebrobasilar insufficiency and presents with ataxia, vertigo, and nausea. In contrast, innominate artery syndrome can additionally present with cerebral ischemia due to blockage of the brachiocephalic trunk and reduced flow to the right CCA and the right subclavian artery. This distinction is important as the clinical presentation is unique and management should be directed accordingly.