Internal jugular vein compression between the atlas and the styloid process

Introduction

Eagle syndrome describes symptoms caused by an elongated styloid process or a mineralized stylohyoid complex ⁠. It typically presents with cervical pain and dysphagia, and computed tomography is the diagnostic gold standard ⁠. In the carotid variant, the styloid process compresses the internal carotid artery and can cause transient ischemic attacks or stroke ⁠.

A jugular variant has since been described, in which an elongated styloid process running next to the transverse process of C1 compresses the internal jugular vein ⁠. In a review of 56 reported cases of the vascular variant, internal jugular vein stenosis was the most common vascular complication ⁠. Patients with styloid-related jugular stenosis most often report insomnia, tinnitus and head noises ⁠, and headache is the most prominent symptom of the jugular variant ⁠. In 46 patients with cervical spondylotic jugular compression, the transverse process of C1, alone or together with the styloid process, accounted for almost all stenotic segments ⁠.

Facial pain can also be the presenting complaint, and it often lateralizes to the side of the venous compression. Venous outflow obstruction at this level has also been reported together with cerebral venous sinus thrombosis.

Several surgical techniques have been used, but there is no consensus on the optimal strategy ⁠. Reported approaches range from styloidectomy with or without partial C1 resection ⁠ to circumferential decompression that adds C1 transversectomy, myectomy of the styloid muscles and wide opening of the carotid sheath ⁠. Whether styloidectomy alone is enough remains unclear.