Witnessing or experiencing a person having a stroke can be a very confusing and scary event. Taking immediate steps can greatly improve the outcome. A cerebral vascular attack, commonly known as a stroke, is when brain cells die due to a lack of oxygen, caused by an absence of circulation of oxygenated blood to that part of the brain.
About 795,000 Americans each year suffer a new or recurrent stroke, and 137,000 people a year are killed by it. That’s about one out of every 18 deaths. It’s the No. 4 cause of death, and on average, every four minutes someone dies of stroke.
Types of stroke
The two main types of stroke include an Ischemic stroke or a Hemorrhagic stroke.
Ischemic strokes are more common, and more often are treatable, while hemorrhagic strokes are less common, and have a higher mortality rate.
Ischemic strokes accounts for about 87 percent of all strokes. They occur when a blood clot, being either a thrombus or embolus, blocks blood flow to the brain. A Thrombus forms within the artery supplying blood into the brain blocking its blood flow. An embolus is a blood clot that formed somewhere else in the body and broke off to become free-floating. This wandering clot may be carried through the bloodstream to the brain causing the blockage.
A hemorrhagic stroke occurs when a weakened blood vessel supplying the brain ruptures preventing blood flow to the brain, that blood accumulates and compresses the surrounding brain tissue. When the rupture is on the brain’s surface it will fill the space between the brain and skull with blood — this is a subarachnoid hemorrhage. If it occurs within the brain, it fills the tissue with blood, it’s known as a cerebral hemorrhage.
The weakened blood vessels that usually cause hemorrhagic stroke include aneurysms and arteriovenous malformations (AVMs). An aneurysm is a ballooning of a weakened region of a blood vessel. If left untreated, the aneurysm continues to weaken until it ruptures and bleeds into the brain. An AVM is a cluster of abnormally formed blood vessels, if any of these vessels rupture; it can cause bleeding into the brain.