A B C D E F G H I J K L M N O P R S T U V W

CEREBROVASCULAR DISEASE - STROKE

What is Cerebrovascular Disease ?

Cerebrovascular disease, or stroke, refers to brain disorders caused when the blood supply to the brain is disrupted in some way. The commonest form of stroke is caused by a blockage of a blood vessel in the brain. This leads to a portion of the brain dying. A blockage may be short lived and produce symptoms lasting less than 24 hours. This is called a transient ischaemic attack (TIA) and is dealt with in another leaflet. About one out of every five strokes is due to bleeding from a blood vessel. These strokes are often more severe. In half of these cases, bleeding occurs within the brain tissue (cerebral haemorrhage). In the other half, the bleeding starts within the coverings of the brain (subarachnoid haemorrhage).

Stroke almost always begins suddenly. Often it produces numbness, or a weakness of the face, arm and leg on one side of the body (called hemiparesis or hemiplegia). Because of the way the brain works, the symptoms are usually on the side of the body opposite to the side of the brain where the damage has occurred. The limbs are usually floppy at first but later become stiff or spastic. Half the field of vision may be lost and speech may become absent or indistinct. The understanding of speech and the ability to communicate may be affected. Sometimes swallowing can be impaired. The stroke may cause drowsiness or loss of consciousness, dizziness, unsteadiness or double vision.

How does Cerebrovascular Disease occur ?

The lining of an artery in the neck or brain may over the years become furred up with fatty deposits known as atheroma. A clot or thrombus may then block the flow of blood through that artery (thrombosis). Thrombosis in a large vessel can lead to a major stroke but milder strokes may occur when very small arteries block, often as a result of hypertension. Alternatively, a clot or embolus may form somewhere else in the body such as in the heart or in one of the neck arteries and may travel in the bloodstream to the brain, where it may block an artery (embolism). Thirdly, a weak area in the wall of an artery (aneurysm) may burst causing bleeding to occur. This may be in the brain substance (intra-cerebral haemorrhage) or in the spaces surrounding the brain (subarachnoid haemorrhage). Sometimes haemorrhage occurs without an aneurysm being found. Occasionally a split in the lining of a blood vessel causes a blockage or embolism which results in a stroke. These splits can be caused when the neck is twisted perhaps in a car accident.

Why does Cerebrovascular Disease occur ?

Most strokes occur in the second half of life and are caused by damage to blood vessels that has occurred over many years. They may have been damaged by high blood pressure, smoking, high cholesterol, heavy drinking, obesity, heart disease or diabetes. Healthy women on the low dose oral contraceptive pill have a 1.5 times increased risk of stroke due to artery blockage. High blood pressure in pill-users increases the risk of stroke threefold. Overwork or stress may cause raised blood pressure but most strokes are not caused by stress or doing too much.

Treatment Involved for Cerebrovascular Disease

Less disabling strokes can be managed by the GP at home. Tests may still be needed to understand the cause, and possibly prevent recurrence. More severe strokes or those where there is uncertainty about what has happened may need admission to hospital for investigation and nursing care. Simple blood tests, a chest x-ray and a heart tracing (ECG) are usually performed to ensure that heart function is satisfactory. Brain scans may be done to locate the damaged area and to ensure that there is no other cause for the brain damage.

Either a CT (x-ray) or MRI (magnetic) scan is performed for this purpose. Ultrasound tests on the heart (ECHO) or neck (Dopplers) may be done, particularly if it is considered that a clot may have formed in these areas and “migrated” to the brain (embolism). Angiograms are x-rays of the head and neck blood vessels, and can demonstrate narrowing or abnormal circulation. If your blood pressure is raised, it may need treatment: this may reduce the risk of further strokes. Swallowing, and bladder functions may have to be monitored and treated; drugs may be needed for this. Aspirin has been shown to reduce the risk of stroke recurrence and to provide a better long-term outcome. It or another drug which reduces the “stickiness” of blood cells is likely to be prescribed for you. If it seems likely that your stroke was caused by an embolism from the heart, blood thinning treatment (an anticoagulant) is likely to be prescribed for you.

Clot-dissolving treatment (called thrombolysis) has been assessed: at the present time it is not considered appropriate in the routine management of strokes. Skilled nursing and early rehabilitation is important. Physiotherapists, occupational therapists and speech and language therapists all play a part in the recovery process.. These treatments may take place in a specialised stroke unit or ward. A home visit may be needed to plan ahead for when you go home. Social workers may advise about benefits and resources to help you and your family to manage. Some people who have very narrow, but not blocked arteries in their neck may be offered surgery to open out the narrowing. If the stroke has been caused by a haemorrhage, brain surgery (craniotomy) may be needed to drain away the blood or to seal off the leaking artery.

During Treatment of Cerebrovascular Disease

There is usually improvement in the damaged functions such as weakness or difficulty speaking. This may be delayed, or may start quickly and then slow down. You may get chest infections, urinary problems, pressure sores, or clots forming in the veins of the legs. The last two of these are to some extent preventable, most readily by keeping the leg muscles active. Anxiety, changes in personality and depression may be problems at early or later stages.

After Treatment of Cerebrovascular Disease

Stroke may recur, causing more disability. Epilepsy may develop. You will be encouraged to reduce the risk of further strokes by stopping smoking and taking more exercise. Drugs may be given to you to reduce the level of blood cholesterol and the risk of blood clotting. Together with control of blood pressure, these measures have been shown to lessen the chance of a further stroke. They also reduce the risk of heart attack, to which you are rather more prone than average. You will be advised not to drive for a month or longer if fits have occurred as part of the stroke, or if you have other disability.

If Cerebrovascular Disease is Left Untreated

Without early assessment, some treatable types of stroke would be missed and complications could occur. Rehabilitation aims to restore function as early and completely as possible.

Effects on Family of Cerebrovascular Disease

Stroke is not inherited but high blood pressure and high cholesterol may be. Your family may be advised to have these checked. Family and friends play an important role in restoring function by encouragement and exercise. Apart from driving and sometimes flying, most activities will be allowed or encouraged. Most people will return home where adjustments may be needed. Community services play an important part in rehabilitation.