What is the management and treatment for bow hunter syndrome?

Bow Hunter Syndrome: Management and Treatment

Diagnosis and Initial Evaluation

Bow hunter syndrome should be diagnosed using dynamic imaging studies demonstrating vertebral artery occlusion or stenosis during head rotation, with digital subtraction angiography with head rotation remaining the gold standard, though dynamic CT angiography, MR angiography, or Doppler ultrasonography are less invasive alternatives. 1, 2

Key Diagnostic Features

• Clinical presentation: Patients typically present with transient vertebrobasilar insufficiency symptoms including syncope, vertigo, dizziness, visual disturbances, ataxia, or tinnitus that are triggered by head rotation (usually to the contralateral side of the dominant vertebral artery) and resolve when the head returns to neutral position 1, 3, 4, 5
• Imaging approach: Dynamic angiography (DSA, CT, or MR) performed with head rotation in the symptomatic position is essential to demonstrate mechanical compression or occlusion of the vertebral artery 1, 2
• Underlying pathology: Look for osteophytes, disc herniation, cervical spondylosis, tendinous bands, tumors, or atlantoaxial instability causing dynamic vertebral artery compression 1, 2

Treatment Algorithm

First-Line: Conservative Management

Conservative management should be attempted initially in all patients with bow hunter syndrome, consisting of cervical collar use to limit excessive neck rotation and patient education to avoid large-angle head deflection. 5

• Cervical collar immobilization restricts provocative head movements 5
• Patient counseling on avoiding positions that trigger symptoms 5
• This approach is appropriate for patients with mild, infrequent symptoms 1

Second-Line: Surgical Intervention

Surgical treatment should be pursued when conservative management fails or symptoms are severe, with posterior cervical fusion being the primary surgical approach for most cases. 1, 3, 2

Surgical Options:

• Posterior cervical fusion: C1-C2 arthrodesis using lateral mass screws and translaminar screws with intrafacet cages for segmental fusion is effective for atlantoaxial pathology 3, 2
• Surgical decompression: With or without fusion, depending on the compressive pathology identified 1
• Bypass surgery: Reserved for specific anatomical situations 1

Surgical intervention has demonstrated excellent outcomes with resolution of vertebrobasilar insufficiency symptoms and no neurological deficits postoperatively. 3, 2

Third-Line: Endovascular Procedures

Endovascular intervention may be considered in specific cases, particularly when concurrent cerebrovascular disease complicates bow hunter syndrome. 1, 4

• Subclavian artery stenting combined with carotid endarterectomy can be effective for patients with concurrent subclavian and carotid stenosis 4
• This approach provides global revascularization and obviates the need for complex vertebral artery surgery 4
• Endovascular treatment is appropriate when the primary pathology involves vascular stenosis rather than mechanical compression 1, 4

Special Considerations

Complications

• Pseudoaneurysm formation: Rare but serious complication requiring urgent surgical stabilization of the affected segment 3
• Posterior circulation stroke: Can occur if diagnosis is delayed or treatment inadequate 1

Young Patients

• Consider bow hunter syndrome in young patients with poor neck posture, loss of cervical physiological curvature, and rotation-dependent symptoms 5
• Dynamic monitoring with color Doppler ultrasound and transcranial Doppler provides noninvasive diagnostic clues 5

Pediatric Population

• While rare in children, bow hunter syndrome should be considered in the differential diagnosis of recurrent ataxia, though it is not a primary diagnostic target for initial evaluation 6

Treatment Selection Criteria

The choice between conservative, surgical, and endovascular treatment depends on symptom severity, frequency of episodes, underlying pathology, and response to initial conservative measures. 1, 2

• Conservative: Mild, infrequent symptoms without neurological deficits 5
• Surgical: Failed conservative management, severe or frequent symptoms, mechanical compression by bony structures or instability 3, 2
• Endovascular: Concurrent vascular stenosis, high surgical risk, or specific anatomical considerations 4