<prompt> The subclan steal syndrome occurs due toOcclusion stenosis of the veebral aeryOcclusionstenosis of the carotid aeryOcclusion of the subclan aery proximal to origin of veebral aeryOcclusion of the subclan aery distal to origin of veebral aery  <response>: Subclan steal:when the arm is used,blood is stolen from the brain the veebral aery .this lead to veebro-basilar ischemia ,which is characterised by dizziness ,coical blindness andor collapse. Ref Harrison20th edition pg 2456 