What is a stroke?

A stroke occurs when a part of the brain gets damaged due to interruption of its blood supply. The symptoms and signs of stroke depend on the size and location of the damaged area. In a "transient ischaemic attack (TIA)," the symptoms of stroke disappear completely within 24 hours.

SYMPTOMS

Common symptoms include:

• weakness of face, arm, leg on one side
• numbness of face, arm, leg on one side
• slurred speech or speech difficulty
• loss of vision
• double vision
• loss of balance or co-ordination
• giddiness together with one of the above symptoms
• loss of consciousness or coma
• the "worst headache in your life"

Symptoms usually occur suddenly and may get worse over the following minutes or hours. They may occur during sleep and be noticed only on waking up.

CAUSES AND RISK OF FACTORS

Blood is supplied to the brain by blood vessels called arteries. These arteries may get blocked, causing an "ischaemic stroke" or "infarct". Less commonly, these arteries may burst, causing a "haemorrhagicstroke" or "brain haemorrhage".

There are a number of factors that increase the risk of stroke:

• older age
• male gender
• high blood pressure (hypertension)
• cigarette smoking
• diabetes mellitus
• high cholesterol
• irregular heart beat (artrial fibrillation)
• certain heart diseases including a recent heart attack
• previous stroke or TIA

DIAGNOSIS

A number of tests are done, including:

• Brain scan: usually a CT scan is performed. Sometimes an MRI scan is needed. The scan will help the doctor confirm the type of stroke and its location.
• Blood tests: to look for underlying diseases such as diabetes mellitus and high cholesterol.
• Chest X-ray, electrocardiogram (ECG): for information on heart diseases.
• Ultrasound studies of the blood vessels in the neck and skull (carotid ultrasound, transcranial Doppler), and of the heart (echocardiogram): to detect conditions that may lead to stroke.
• Angiogram: a small tube is inserted into the groin and passed along the blood vessel till it reaches the brain. Adye is injected and X-ray pictures are taken. These provide information on the location and severity of vessel blockage or bleed.

TREATMENT

While in hospital, your condition will be closely monitored. About 20% of patients will worsen within the first week. Very high blood pressure, blood sugar and cholesterol will need to be lowered by dietary control and medications. Those who are unable to swallow safely may need to be fed by a tube through the nose.

Rehabilitation aims to get the patient to be independent in his daily activities. It starts as soon as possible through physical, occupational and speech therapy. In "ischaemic stroke", the use of "blood thinners" such as "antiplatelet" and" anticoagulant" medication significantly reduces the risk of a second stroke. If there is severe narrowing in a neck artery leading to a minor stroke or TIA, surgery to remove that narrowing (carotid endarterectomy) reduces the risk of another stroke.

If the "hemorrhagic stroke" is due to rupture of a "bubble" on a blood vessel (aneurysm), the aneurysm can be clipped surgically, or blocked up by specially-inserted coils. Rupture of an "arteriovenous malformation (AVM)" can also cause a hemorrhagic stroke. .Surgery, specially-inserted glue or gamma-knife radiation may be needed to treat it. Accumulation of brain fluid may need to be relieved by a surgically-inserted" drain".

CHANCES OF RECOVERY

Recovery after stroke is a natural process. Up to a third of stroke patients recover fully, a third recover partially, and a third do not recover at all. About 10 to 20% may not survive the early period after the stroke. Recovery takes time. Most recovery occurs in the first 3 to 6 months, but it may continue slowly for many years.

There is a 5 to 15% chance a year of the stroke recurring. To reduce the chance of another stroke, all medications should be taken regularly and smoking must be stopped.

CAN STORKE BE PREVENTED?

Regular visits to a family doctor will help in early detection and treatment of high blood pressure, diabetes mellitus, high cholesterol and heart diseases. Leading a healthy lifestyle will also help to prevent an onset of stroke. Exercise regularly and avoid smoking. All medications should be taken regularly unless advised by the doctor.