Would you know the symptoms of a stroke if it were to strike? Stroke is the second leading cause of disability in the world. Worldwide, fifteen million people suffer strokes each year and a third of them die as a result. Another third becomes permanently disabled. Stroke is the fifth leading cause of death in the United States.
The incidence of stroke is decreasing in the industrial world but increasing in the developing world. Frighteningly, it’s estimated that stroke mortality will triple in the next twenty years in Latin America, sub-Saharan Africa, and the Middle East. (1) Stroke can strike anyone at any age, although it is much more common in people over the age of 60.
What is a Stroke?
Simply put, a stroke occurs when the blood supply to the brain is cut off. Deprived of oxygen, brain cells quickly die. Someone who suffers a stroke may lose memories or abilities that are in the affected parts of the brain.
There are two types of stroke (2):
Hemorrhagic – occurs when a blood vessel leaks or a brain aneurysm (enlarged artery) bursts and blood flows into or around the brain, causing pressure.
- Intracerebral hemorrhage is when the damaged vessel leaks blood directly into brain tissue, killing brain cells. In some cases, the hemorrhage occurs due to a genetic malformation of arteries and veins in the central nervous system (AVM, arteriovenous malformation). If this condition is appropriately diagnosed, it can be treated to prevent stroke.
- Subarachnoid hemorrhage occurs when there is bleeding in the space between the brain and the surrounding tissues. This is usually caused by a burst aneurysm but can occur as the result of head injury or the use of blood-thinning medication.
Ischemic – caused by a blockage or blood clot in a blood vessel, cutting off blood supply to the brain. This is the most common type of stroke.
- A blood clot can form and arterial plaque can break off anywhere in the circulatory system. If such a mass moves up to the brain and reaches a blood vessel too small for it to pass through, it can get stuck there. This is called an embolic stroke.
- A thrombotic stroke refers to the situation in which a blood clot forms inside one of the arteries that bring blood to the brain, causing a blockage.
- A transient ischemic attack (TIA) is commonly called a “mini-stroke”. It is a temporary blockage of blood to the brain and causes no long-term damage. Symptoms of a stroke may manifest themselves but will pass within a few minutes. It is critically important to see a healthcare provider if you think you may have experienced a TIA—it’s often a precursor to a full-blown ischemic stroke. (3)