What is a Stroke?

A stroke is a sudden loss of brain function – a “brain attack”. It is caused by either a restriction of blood flow to the brain (ischemic stroke) or bleeding inside or around brain tissue (hemorrhagic stroke). Brain cells in affected areas die and cause a change in physical and/or cognitive ability depending on the location of the injury.

Three basic types of stroke:

1. Ischemic stroke

Ischemic strokes account for 80% of all strokes. They are caused by a restriction of blood flow to the brain due to a blood clot. Atherosclerosis, which is the narrowing of an artery, contributes to most ischemic strokes as it prevents adequate blood supplying brain tissues. This narrowing can be a result of a build up of fats, calcium or scar tissues. Altogether, these deposits on the walls of arteries are known as plaque.

Thrombotic strokes refer to strokes that are caused by the formation of blood clots at the spot of infarct, while embolic strokes refer to strokes that are caused by a blood clot formed at elsewhere and travels to the spot of infarct.

*This video was created by the American Stroke Association

2. Hemorrhagic stroke

Hemorrhagic strokes account for 20% of all strokes. They are caused by bleeding in the brain where the bleeding damages brain tissue by disrupting normal blood flow and essentially flooding the brain. This could happen as a result of brain trauma, aneurysm or a malformation of an artery (also known as Arteriovenous Malformation).

The two types of hemorrhagic strokes are intracranial hemorrhage, which is bleeding within the brain tissue itself; and subarachnoid hemorrhage, which is bleeding into an area between the brain and the skull, known as the subarachnoid space.

*This video was created by Nucleus Medical Media

3. Transient Ischemic Attack (TIA)

Transient Ischemic Attack (TIA) is essentially a mini-stroke. Although the symptoms are almost the same as the symptoms of a stroke, the duration is much shorter, usually lasting from a few minutes to several hours before resolving itself. Just as plaque and blood clot can cause a stroke, these two factors may also cause TIA as well. Although TIA may cause little to no damage at all, individuals who have experienced an episode of TIA are asked to seek medical assistance immediately as they are at a higher risk of developing a stroke.  

*This video was created by High Impact Graphics