Stroke
What is Stroke?
A stroke or “brain attack” occurs when the vessels supplying blood to the brain are blocked, interrupting the blood flow. This results in the death of the brain cells. Depending on the area of the brain involved and the extent of brain cell death, the specific body functions such as speech, movement or memory may be affected.
What are the symptoms?
The symptoms may be: Loss of consciousness. Sudden numbness or weakness of the face, arm or leg. Sudden confusion and difficulty in speaking or understanding. Sudden problem in vision. Dizziness, loss of balance and coordination. Sudden severe headache and vomiting.
What are the riskfactors?
The risk factors may be controllable or uncontrollable. Uncontrollable risk factors are: Age. A family history of stroke. Diabetes.Controllable risk factors may include:High blood pressure: A high blood pressure may put stress on the blood vessel walls leading to a stroke.Heart Disease: The heart may beat rapidly (as high as 400 times a minute) or the beat may be irregular (fibrillation). The blood may pool in the heart and form clots which may then be carried to the brain, causing a stroke. Coronary Heart Disease and High Cholesterol: High levels of cholesterol in the blood can lead to the build up of plaques in the arteries and clog them, thereby increasing the stroke risk.Personal history of stroke: An attack of stroke may increase the chances of another stroke.Lifestyle factors that increase stroke risk include smoking, excessive alcohol intake and obesity.
What are the types?
A stroke may be ischaemic or haemorrhagic Ischaemic stroke: An ischaemic stroke is caused when a clot blocks a blood vessel in the brain cutting off the blood flow. The blood clot may form elsewhere in the body and travel through the blood stream to the brain. In the brain the clot may block the blood vessels causing an embolic stroke. In thrombotic stroke, the blood flow may be impaired because the clot originates in one or more of the arteries supplying blood to the brain. Haemorrhagic Stroke – Strokes caused by the rupture of a blood vessel in the brain are called haemorrhagic strokes. They can be caused by a number of disorders such as high blood pressure or cerebral aneurysms (a bulge in the wall of a blood vessel, usually present since birth). Aneurysms develop over a number of years and may suddenly burst causing a stroke. The presentation of symptoms depends on the area of the brain affected by the disease process.The right hemisphere of the brain controls the analytical and perceptual tasks. It also controls the movement of the left side of the body. A stroke in the right hemisphere may cause paralysis of left side of the body. This is known as left hemiplegia. People affected by this may have problems with their perceptual abilities. They may also have short-term memory problems.The left hemisphere of the brain controls speech and language abilities. A left hemisphere stroke causes paralysis of the right side of the body. Speech and language problems, shorter retention spans, difficulty in learning new information and certain conceptual problems may be caused by this type of stroke.If the cerebellum of the brain is affected by a stroke the patient may have coordination and balance problems, dizziness, nausea and vomiting.The brain stem controls all involuntary, life support functions such as breathing rate, blood pressure and heartbeat. It also controls the eye movements, hearing, speech and swallowing. A patient with a brain stem stroke may develop paralysis of one or both sides of the body.
How is the diagnosis made?
A quick neurological examination is the first step. The symptoms are assessed and certain blood tests may be carried out. An electrocardiogram and CT scan may also be done. MRI may be advised to detect subtle changes in the brain. Neurosurgeons may advise an MRA (magnetic resonance angiography) to detect blockage of the brain arteries inside the skull.
What is the treatment?
The treatment for stroke includes drugs, surgery and rehabilitation.The most important drugs to prevent or treat stroke are anticoagulants and antiplatelet agents. These agents prevent the formation of blood clots that may become lodged in an artery causing strokes. Antiplatelet drugs prevent clotting by decreasing the activity of platelets or blood cells that contribute to the clotting. The most widely used antiplatelet drug is aspirin. Others include clopidogrel and ticlopidine. Anticoagulants reduce stroke risk by reducing the clotting property of the blood. The most commonly used are warfarin and heparin. Thrombolytic agents are used to treat acute ischaemic strokes caused by the blockage of a blood vessel. These drugs halt the stroke by dissolving the blood clot that is blocking the blood flow to the brain. Neuroprotectants are drugs that protect the brain from secondary injuries caused by stroke. Surgery may be done to prevent stroke, to treat acute stroke or to repair blood vessel malformations in and around the brain. There are two types of surgery for stroke prevention and treatment: carotid endarterectomy and extracranial / intracranial bypass (EC/IC bypass). Carotid endarterectomy is a surgical procedure in which fatty deposits (plaques) from the inside of one of the carotid arteries (located in the neck and supplying blood to the brain) are removed.EC/IC bypass surgery is a procedure that restores blood flow to a blood-deprived area of brain tissue by rerouting a healthy artery in the scalp to the area of brain tissue affected by a blocked artery.Clipping involves clamping off the aneurysm from the main blood vessel, which reduces the chance that it will burst and bleed. Post-Stroke Rehabilitation: Physical therapy aims at relearning walking, sitting, lying down and switching from one type of movement to another. The physical therapist uses training and exercises to help restore movement, balance and coordination to the affected person. Occupational therapy aims at developing self-help skills in the person so that he becomes independent in taking care of himself. Speech therapy focuses on relearning speech and language skills. Psychological problems such as depression, anxiety, frustration and anger are common post-stroke disabilities. Talk therapy along with appropriate medication can help alleviate some of the mental and emotional problems that result from stroke.