Discuss subclavian steal syndrome, adding its neurological symptoms скачать в хорошем качестве

Discuss subclavian steal syndrome, adding its neurological symptoms

Subclavian steal syndrome and subclavian steal phenomenon both result from severe proximal subclavian artery stenosis or occlusion resulting in retrograde flow in the ipsilateral vertebral artery. Terminology Subclavian steal phenomenon refers to steno-occlusive disease of the proximal subclavian artery with retrograde flow in the ipsilateral vertebral artery. Subclavian steal syndrome is the same as subclavian steal phenomenon with the addition of cerebral ischemic symptoms. Epidemiology There is an increased incidence with age and the greater male predilection with a M:F ratio of 2:1. It is commoner on the left side with L:R ratio of ~3:1. Clinical presentation ipsilateral upper limb weak or absent pulse decreased systolic blood pressure in the affected side; systolic blood pressure difference between the brachial arteries are more than 20 mmHg 3 arm claudication (rare due to collateral perfusion) neurological (exacerbated by arm exercise) dizziness/vertigo/syncope ataxia visual changes dysarthria weakness/sensory disturbances Pathology Subclavian artery steno-occlusive disease results in decreased perfusion to the ipsilateral arm and hand. Subclavian artery branches distal to the obstruction act as collateral pathways to maintain upper limb perfusion. If the level of stenosis or occlusion is proximal to the vertebral artery, then reversal of flow in the vertebral artery may occur, thereby stealing blood from the posterior circulation. When the upper limb is exercised, blood is diverted away from the brain to the arm. Whether or not this steal phenomenon causes cerebral ischemic symptoms depends on the adequacy of intracranial collateral circulation, especially the posterior communicating arteries. Patients with adequate intracranial collateral circulation are usually asymptomatic; 80% of symptomatic patients have lesions elsewhere in the intracranial or extracranial cerebral circulation. Patients in whom the left vertebral artery arises directly from the aortic arch are protected from subclavian steal syndrome on the left. #subclavianstealsyndrome #subclaviansteal #vertebralartery