Stroke

Stroke occurs when the blood supply to a part of the brain is suddenly blocked or diminished, altering the body function controlled by that area of the brain. If any part of the body – including the brain - is without a source of fresh blood and oxygen, the cells will be injured and may die. Although some cell injury is reversible, the death of brain cells is permanent, usually leaving lasting disability.

There are three main types of stroke:

Thrombotic – the most common, caused by a clot that forms in an artery that may already be partially obstructed by a buildup of plaque (fat) in its walls and blocks the flow of blood.
Embolic – caused by a circulating piece of a clot that lodges in a blood vessel in the brain. The clot forms elsewhere in the body, usually in the heart, and moves freely until it reaches the small vessels in the brain and cannot move further.
Haemorrhagic – may be caused by the rupture of a blood vessel, causing blood to accumulate in the brain. The rupture may be of an aneurysm - a weak spot in the artery wall - or result from head injury.
Aneurysms are often caused by congenital defects or high blood pressure. Haemorrhagic strokes are the most severe and are often fatal. The chance of a full recovery is less than that for the other two types.

Most strokes are preceded by one or more mini-strokes (called transient ischemic attacks or TIA’s) that should act as a warning to seek medical attention immediately. The most common symptoms of a stroke are:

sudden numbness, weakness, or paralysis of the face, arm, or leg – usually on one side of the body
loss of speech or trouble talking or understanding what is said
sudden blurred vision, dizziness, loss of balance, or severe, unexplained headache.

Treatment of stroke depends on the areas affected and the damage done. With strokes caused by blood clots, use of “clot busting” drugs (as used in treating heart attacks) can be helpful in the early stages. Often, anticonvulsant drugs are used in conjunction with other therapies. It is important that anyone with sudden onset of symptoms suggestive of a stroke seek medical attention as soon as possible.