Mastication Steal Syndrome.

A 56-year-old woman presented with episodic vertigo, dizziness, and diplopia during meals and prolonged verbal presentations at work. Subsequent work-up included an eventual catheter-based angiogram revealing an ostial left external carotid artery (ECA) occlusion with reconstituted retrograde flow via a variant collateral branch from the dominant left vertebral artery. The findings demonstrate that repetitive activities involving craniofacial muscular systems supplied by the ECA result in a symptomatic arterial steal syndrome via the enhanced diverted flow from the collateral vertebral-basilar arterial system. A left ECA endarterectomy with reimplantation of the vessel was performed, and the patient has been episode free thereafter.