The term "stroke" refers to a serious condition where the blood supply to a part of the brain is suddenly stopped. This is a medical emergency and requires urgent treatment in order to prevent serious, long lasting and life threatening consequences.
Symptoms of stroke
The symptoms of stroke can be remembered through the mnemonic - FAST, with each letter of this word standing for:
F - Face - Stroke can cause paralysis of the facial muscles that may present as drooping of the face on one side and an inability to smile.
A - Arms - Weakness, heaviness and numbness in the upper body limbs may affect the ability to lift one or both arms.
S - Speech - Speech may be slurred, garbled or completely absent.
T - Time - Time is a vital parameter in stroke patients. The earlier a patient receives medical attention, the less risk there is of adverse consequences.
Causes of stroke
The brain is a highly vascularized organ and has a rich supply of small and large blood vessels. This network of blood vessels allows for an adequate blood supply to all parts of the brain. If the blood supply to any brain region is cut off, the cells in that region begin to die and any parts of the body associated with the function of that region are affected. For example, if the motor cortex is destroyed due to a stroke, control of the voluntary movement on the opposite side of the body is lost, with this side becoming paralyzed.
The sudden lack of blood supply to brain areas that occurs during a stroke is usually caused by a blood clot. This is called ischemic stroke and is one of the most common forms of stroke. Another form of stroke is the hemorrhagic stroke, which occurs due to the rupture of a weakened blood vessel (usually caused by an aneurysm). The leaking blood accumulates and causes compression of the surrounding brain tissue.
Treatment of stroke
Treatment of stroke depends on the type of stroke and the part of the brain that is affected. Drugs may be used to prevent or dissolve blood clots in the brain and also to reduce blood cholesterol levels. Surgery may also help in clearing an obstruction or repairing a ruptured vessel.
Reviewed by Sally Robertson, BSc