It can also cause this obstruction by an embolus, which is nothing but a thrombus (blood clot) located at a distant site of the damaged artery. It may be at the level of the heart or great vessels of this organ, and for a moment it appears, he travels with the brain plus iq  bloodstream and blocks a far more cerebral vessel. Other entity that may cause an ischemic lesion is hypoxia, ie, a decrease in the oxygen concentration of the blood to the brain and cause it may be a drop in blood pressure or hypotension, which could be secondary to a heart attack.

http://healthnbeautyfacts.com/brain-plus-iq/