A stroke is the sudden death of a portion of the brain cells due to lack of blood supply.

Stroke can be caused by rupture of an artery to the brain, provoking haemorrhage and damages to surrounding brain tissue, or by blockage of an artery following thrombosis or embolism.

In particular, thrombosis occurs when a blood clot breaks and travels into an artery of the brain, blocking the flow of oxygen-rich blood. Embolism is when an embolus (a piece of cholesterol deposits) or a little thrombus breaks off from atherosclerotic plaque and travels through the blood stream to form an embolism in a brain artery. Both thrombosis and embolism cause cerebrovascular blockage leading to ischemia (lack of blood supply affecting an area of the brain).

Subarachnoid haemorrhage may be caused by rupture of cerebral aneurysm, a bulge in a blood vessel, which is then weakened.

 

Symptoms

The symptoms are similar to those of TIA (transient ischemic attack) but the latter are transient while stroke symptoms remain permanent or get worse instead of disappearing after few hours. They may include:

• sudden weakness or numbness of the face, arm, or leg, on one or both sides of the body;

• sudden confusion or difficulty speaking or understanding (aphasia, dysphasia);

• sudden problems with vision such as stare, dimness, loss of vision in one eye ( hemianopsia) or double vision (diplopia);

• sudden dysphagia;

• sudden apraxia;

• sudden problems with balance or coordination;

• vacillation, dizziness, migraine;

• mental confusion.

In addition, in the case of rupture of aneurysm, loss of consciousness and severe headaches may occur.