Occlusion or severe stenosis of the subclavian artery origin, with the vertebral artery that serves as collateral arterial vessel that "steals" blood to the posterior brain and cerebellum..
It presents disorders of the vertebral basic-type, characterized by headache, dizziness, visual difficulties, which often occur during physical activity on top. The disorder, however, involving the upper limb are those of an intermittent claudicatio with fatigue, paresthesia, tingling.
If they do not go better for compensating efficient collateral arterial vessels, it is necessary, where possible, an endovascular treatment by of percutaneous angioplasty and stents, otherwise it is indicated supraclavear surgery with carotid-subclavian artery bypass or direct carotid-subclavian anastomosis.