ACUTE ISCHEMIC STROKE Stroke is defined as loss of brain function due to disturbance in blood supply to the brain. This can be due to lack of blood flow caused by blockage which may be due to thrombosis, arterial embolism, or a haemorrhage (leakage of blood) As a result, the affected area of the brain is unable to function, which might results in inability to move one or more limbs of the body, inability understand speech, or an inability to see one side i.e. visual disturbance . stroke may cause permanent neurological damage, complications, and death. Strokes can be classified into two major categories: ischemic and hemorrhagic. Ischemic strokes are those that are caused by interruption of the blood supply, while hemorrhagic strokes are the ones which result from rupture of a blood vessel or an abnormal vascular structure. About 87% of strokes are caused by ischemia, and the remainder by hemorrhage. Ischemic stroke Strokes can be either ischemic or hemorrhagic. In an ischemic stroke, the blood supply to part of the brain is cut off because blood clot or some form of plaque stops blood supply to brain Blood clots can travel to the brain from another artery (artery-to-artery embolization) or they can come from the heart (cardioemblic stroke). Ischemic strokes can be caused by a blockage anywhere along the arteries feeding the brain. The blockages can occur for a variety of reasons, including: The formation of fatty material (atheroma) along the walls of an artery, which reduces blood flow Breaking off of atheroma from the artery wall. The material can flow with the blood and become stuck in a smaller artery, causing a blockage. Blood clots that break loose from the heart or one of its valves, known as an embolus. The clot can travel up the arteries of the brain and lodge there, causing an embolic stroke or cerebral embolism. This type of stroke is most common in people who have recently had heart surgery and in people who have defective heart valves or abnormal heart rhythms (especially atrial fibrillation). Inflammation or an infection that narrows blood vessels that lead to the brain Consumption of Drugs, such as cocaine and amphetamines, which can also narrow the blood vessels Strokes may also cause swelling in the brain. The pressure that results can damage brain tissue more, making neurologic problems worse, even if the stroke itself does not enlarge.
Article publié pour la première fois le 01/10/2011