Diagnosis and management of bow hunter's syndrome: 15-year experience at barrow neurological institute.

BACKGROUND: Bow hunter's syndrome is a rare vascular phenomenon characterized by insufficiency of the posterior cerebral circulation induced by rotation of the head within normal physiologic range. The neurosurgical literature on evidence-based diagnosis and management of the disease is scarce, and reports are largely limited to case studies.
METHODS: A retrospective chart review was performed on all patients referred to Barrow Neurological Institute during the period 1999-2013 with signs and symptoms that were possibly indicative of bow hunter's syndrome. Demographic data from patient charts were collected, and the patients' imaging studies were reviewed.
RESULTS: There were 14 patients referred to Barrow Neurological Institute with symptoms concerning for bow hunter's syndrome, and 11 of these patients were confirmed to have dynamic vertebral artery compression on angiography. The location of compression was centered on C1-2 (50%) or C5-7 (50%). The compressed vertebral artery was typically the left artery (72.7%), and in 54.5% of cases, rotation of the head to the contralateral side produced symptomatic dynamic compression. Surgical decompression, via either an anterior (44.4%) or a posterior (55.6%) approach, was eventually performed in 9 patients. Decompression alone was performed in all cases; however, 1 patient developed cervical instability requiring an anterior cervical instrumented fusion 5 years later.
CONCLUSIONS: Decompression without fusion is a safe, reliable surgical option in patients with bow hunter's syndrome. Decompression is performed via a posterior approach for atlantoaxial vertebral artery compression and via an anterior approach for subaxial compression. Long-term complications include cervical instability, which may necessitate internal fixation and fusion.