A dangerous cerebral event that can lead to lasting, devastating effects or even death is what we call a stroke. A stroke is caused by an interruption in the blood supply to the brain. Without blood and oxygen, the brain begins to die. There are three main types of stroke: Transient ischemic attack (TIA) or “mini stroke,” ischemic stroke, and hemorrhagic stroke.
TIA can be thought of as a warning sign for a future stroke attack. It is the result of temporarily blocked blood flow with symptoms only lasting for a short period. Ischemic and hemorrhagic strokes, however, have lasting effects.
Ischemic stroke
It is estimated that 87% of strokes that occur are ischemic. They are the result of a clot-preventing proper blood flow to a section of the brain. Depending on the origin of the clot, an ischemic stroke can be either embolic or thrombotic. Embolic strokes are the result of a blood clot breaking off from a different location and traveling to the brain. Once in the brain, the clot lodges in a small enough blood vessel, blocking blood flow. Thrombotic strokes occur when the blood clot originated in the brain, eventually accumulating to block blood flow altogether. Both types of ischemic stroke require treatment to get rid of the blood clot to prevent further damage.
Hemorrhagic stroke
There are two types of hemorrhagic strokes: intracerebral and subarachnoid. Intracerebral hemorrhages are the most common type of hemorrhagic stroke. They happen when a blood vessel in the brain bursts and leaks blood into the surrounding tissue. The blood that was leaked puts pressure on the surrounding blood cells and damages them. Subarachnoid hemorrhages occur when there is bleeding in the area between the brain itself and the thin tissue that covers it (called the subarachnoid space). Hemorrhagic strokes can be caused by high blood pressure, aneurysms or arteriovenous malformation, which has to do with an abnormal connection between veins and arteries.
