What is a stroke ?

Stroke happens when the blood supply to part of the brain is cut off. Without blood, brain cells can be damaged or die.

This damage can have different effects depending on where it happens in the brain. It can affect people’s body, mobility and speech, as well as how they think and feel.

2 stroke types

  • The most common type of stroke, in 87% of cases, is caused by a blockage of blood flow to the brain.
    This is an ischemic stroke (aka: brain attack).

    This occurs in two ways:
    • The blood clot causing the blockage forms in an artery directly supplying the brain and is called a thrombus.
    • The blood clot forms elsewhere in the body and is transported to block an artery supplying the brain and is called an embolus.

  • The primary goal is to restore the flow of blood to the parts of the brain affected by the stroke by dissolving the clot, removing the clot or by otherwise resolving the blockage.
Ischemic Stroke: clot interrupting blood flow and therefore oxygen supply to the brain.
  • The second one is a hemorrhagic stroke (13% of strokes). It occurs when a weakened blood vessel bursts, causing blood to leak out of the vessel and into the surrounding brain tissue.

  • There are two types of weakened blood vessels that usually cause a hemorrhagic stroke: aneurysms and AVM’s (arteriovenous malformation).

  • These weak blood vessels can widen over time and can affect the function of the surrounding brain tissue. In extreme cases, the blood vessel may burst from the high pressure of blood flow, causing a hemorrhagic stroke (bleeding in the brain).
Hemorrhagic Stroke: blood leaking out of the blood vessel into surrounding brain tissue.