Posterior Occipito-cervical Fusion for Bow-hunter Syndrome: A Case Report

Abstract

Introduction: We performed posterior occipito-cervical fusion (Oc-C3) in a patient with bow-Hunter syndrome after annulo-posterior arch resection for cervical myelopathy due to annular-axis osteoarthritis.

Case Report: A 59-year-old male underwent annulo-posterior arch arch resection for cervical myelopathy due to atlantoaxial spondylolisthesis six years ago. The patient shouted to the referring physician with visual impairment of the left eye, dysarthria, right upper and lower ataxia, and lightheadedness. Head MRI/MRA revealed bilateral vertebral artery (VA) stenosis at the level of the annulus, cerebellar infarction, and occipital lobe infarction. Angiography also showed complete occlusion of the bilateral VA with right head rotation, leading to a diagnosis of Bow-hunter syndrome associated with annular-axis osteoarthritis. Procedures such as intracranial stenting and intracranial vascular bypass were considered by the referring physician to prevent VA restenosis and recurrent stroke. Cervical spinal surgery was considered necessary, and the patient was referred to our hospital. Cervical spine radiography revealed annular-axis osteoarthritis progression. The bilateral VAs was considered to be in a state of repeated occlusion and opening depending on the cervical position. A contrast-enhanced CT scan with a halo vest showed improved blood flow in the bilateral VAs. Posterior Oc-C3 was performed to prevent VA restenosis and recurrent stroke. Postoperatively, bilateral VA blood flow was improved. Six months after surgery, CT imaging revealed good bone fusion and no recurrence of cerebral infarction was observed.

Conclusions: Posterior Oc-C3 was performed in a patient with Bow-hunter syndrome to prevent recurrence of cerebral infarction.