Carotid Artery Entrapment By Hyoid Bone - A Rare Cause of Recurrent Strokes in a Young Patient.

The search for etiology of stroke in a young patient may present a diagnostic challenge. In rare cases, chronic trauma to the carotid artery may be the cause of cerebral thromboembolic events. The hyoid bone lies in close proximity to the carotid artery bifurcation, and anatomic variants have been implicated in carotid compression, stenosis, dissection, and pseudoaneurysm. We report a case of recurrent strokes in a 32 year-old woman due to an elongated hyoid bone causing thrombus formation in her right internal carotid artery (ICA) resulting in recurrent embolic strokes confirmed on diffusion-weighted magnetic resonance imaging (MRI). Computed tomography angiography (CTA) of the neck and head demonstrated the right hyoid bone was located between the ICA and external carotid artery (ECA), just above the carotid bifurcation, with residual non-occlusive thrombus in the right ICA. Carotid duplex ultrasonography confirmed that with the neck in neutral position the hyoid was located between the ICA and ECA; however with neck rotation the hyoid slipped across the ICA and out of the bifurcation. There was no evidence of carotid stenosis. Following an initial course of anticoagulation and anti-platelet therapy, resection of the greater cornu of the hyoid bone with release of the right ICA was performed. One year post-operatively the patient had complete return of neurologic function and had no further neurologic events. Hyoid bone entrapment of the carotid artery is a rare etiology of thromboembolic stroke caused by repetitive local trauma. The diagnosis can be confirmed by carotid duplex with provocative maneuvers. Partial hyoid resection is a safe and effective treatment to relieve recurrent symptoms. Hyoid bone entrapment may be an important and under-recognized cause of stroke in young adults.