Stroke

What is a stroke?
A stroke is the sudden death of a portion of the brain cells due to lack of oxygen. A stroke occurs when blood flow to the brain is impaired resulting in abnormal brain function. Brain blood flow can be impaired by blockage or rupture of an artery to the brain.

What causes a stroke?
Blockage of an artery of the brain by a clot (thrombosis), leading to deprivation of blood and oxygen, can cause a stroke. Typically, a clot will form in a blood vessel that has been previously narrowed due to atherosclerosis ("hardening of the artery").

When a blood clot or a piece of atherosclerotic plaque (cholesterol and calcium deposits on the wall of the artery) lodges in an artery of the brain, it blocks the flow of oxygen-rich blood.

A cerebral haemorrhage occurs when a blood vessel in the brain bursts and bleeds into the surrounding brain tissue. This too can be a cause of a stroke. All the above causes of stroke lead to deprivation of oxygen to the brain tissue and its resultant death.

Risk factors for stroke:

Arterial Hypertension
Cigarette smoking
Diabetes mellitus
Hyperlipedaemia
Polycythaemia
Thrombocythaemia
High alcohol intake
Positive family history
Oral contraceptives
Trauma

What are the features of stroke?
The most common symptom is weakness or paralysis of one side of the body or the other. There may be partial or complete loss of voluntary movement of and/or sensation in a leg and/or arm. A stroke can result in speech problems and weakens muscles of the face, which can cause drooling. Numbness or tingling is very common. A stroke can cause difficulty inbreathing and even unconsciousness.

How is a stroke diagnosed?
A stroke is a medical emergency. Anyone suspected of having a stroke should be taken to a medical facility immediately for evaluation and treatment. Other causes that can mimic a stroke include brain tumors, subdural hematomas (collections of blood between the brain and the skull), or brains abscess (a collection of pus in the brain caused by bacteria or a fungus). Viral encephalitis can cause symptoms similar to those of a stroke as can an overdose of certain medications. Following tests are generally carried out in the assessment of a stroke.

Routine Testing | Additional Test | What is the treatment of a stroke?
Management of acute Stroke.