A stroke is commonly known as a brain attack. In stroke, the
blood supply to a part of the brain is suddenly diminished or
cut off. The reason for this depends on the type of stroke you
have. In about 15 percent to 20 percent of cases, the cause is
unknown. There are two major types of stroke: - Ischemic stroke
is the most common type of stroke. A blood clot blocks the flow
of blood to one area of the brain, depriving that area of
oxygen. - Thrombotic stroke is a type of ischemic stroke. It
accounts for 40% to 50% of all cases of stroke. A blood clot
forms in one of the brain's arteries, blocking blood flow to the
area of the brain that is "downstream" to this blood vessel. In
most cases, the blood clot forms where the artery was already
narrowed as a result of atherosclerosis (cholesterol plaque). A
specific type of thrombotic stroke affects small blood vessels
that deliver blood deep within the brain. When these small, deep
vessels are involved, the stroke is named a lacunar stroke. -
Embolic stroke is a ty