A stroke occurs when there is a disruption of oxygen-rich blood to a portion of the brain, causing brain cells to die. An ischemic stroke means that there is an interruption in the blood flow to a portion of the brain, while a hemorrhagic stroke means that a blood vessel has ruptured in a portion of the brain.
The severity of the results of a stroke depend on which region of the brain was affected and the functions that region controls. The larger the region that is deprived of oxygen, the more severe the symptoms can be. Immediately following a stroke, an individual may have sudden weakness or paralysis, difficulty speaking or writing (aphasia) and difficulty with memory.
Frequent causes: atherosclerosis (plaque build-up inside arteries), hypertension, aneurism, vascular malformation, etc. Occasionally, the cause is unknown.