A stroke occurs when the blood supply is lost to a certain section of the brain. Often, this is due to atherosclerosis, wherein the walls of blood vessels thicken. In transient ischemic attacks (TIAs), the blockage to blood flow is temporary and symptoms rapidly disappear. However, when there is a cerebral vascular accident (CVA), the blockage lasts long enough to cause cell death in a significant section of the brain. Certain natural supplements may support the prevention of strokes, such as policosanol; and for after a stroke, glycine, and vinpocetine, among others.