A stroke, also known as cerebrovascular accident (CVA), is an acute neurological injury in which the blood supply to a part of the brain is interrupted. That is, a stroke involves the sudden loss of neuronal function due to disturbance in cerebral perfusion. This disturbance in perfusion is commonly arterial, but can be venous.
The part of the brain with disturbed perfusion no longer receives adequate oxygen. This initiates the ischemic cascade, which causes brain cells to die or be seriously damaged, impairing local brain function. Stroke is a medical emergency and can cause permanent neurologic damage or even death if not promptly diagnosed and treated. It is the third leading cause of death and the leading cause of adult disability in the United States and industrialized European nations. On average, a stroke occurs every 45 seconds and someone dies every 3 minutes. Of every 5 deaths from stroke, 2 occur in men and 3 in women.
Risk factors include advanced age, hypertension (high blood pressure), diabetes mellitus, high cholesterol, and cigarette smoking. Cigarette smoking is the most important modifiable risk factor of stroke.
The term “brain attack” is starting to come into use in the United States for stroke, just as the term “heart attack” is used for myocardial infarction, where a cutoff of blood causes necrosis to the tissue of the heart. Many hospitals have “brain attack” teams within their neurology departments specifically for swift treatment of stroke.
Types of stroke
Strokes can be classified into two major categories: ischemic and hemorrhagic. Ischemia can be due to thrombosis, embolism, or systemic hypoperfusion. Hemorrhage can be due to intracerebral hemorrhage or subarachnoid hemorrhage. ~80% of strokes are due to ischemia.
Interruption in the supply of blood to a brain part known as CVA (cerebrovascular accident), a stroke, is acute neurological injury. Stroke involves sudden neuronal functional loss because of cerebral perfusion disturbance that is normally arterial but could possibly be venous also.
Brain part having interrupted perfusion does not receive oxygen adequately. That leads to cascading effect of ischemic process causing serious damage to cells, or death of cells impairing the local functioning of the brain. Stroke being a medical exigency can permanently cause neurological damage, and even death if not treated or diagnosed promptly. Stroke is death’s third top cause, and major disability cause in adults in industrialized nations of Europe and the US. The average occurrence of every stroke is 45 seconds, and 3 minutes for every death. Of every five deaths resulting from stroke, 3 occur in women and 2 in men.
High blood pressure (hypertension), Cigarette smoking, diabetes mellitus, advanced age, high cholesterol, are risk factors. Cigarette smoking greatly modifies stroke risk factor.
In America, stroke is termed as a brain attack, just as heart attack for myocardial infarction, wherein blood interruption causes necrosis to heart tissue. Neurology departments of most hospitals have teams for swiftly treating brain attack.
Hemorrhagic and ischemic are two main stroke categories. Systemic hypoperfusion, embolism, or thrombosis causes ischemia. Subarachnoid hemorrhage or intracerebral hemorrhage causes hemorrhage. Ischemia causes about 80 percent strokes.