What is a stroke?

The term “stroke” is actually a very broad term. A stroke occurs when there is a problem with a blood vessel in the vein. This includes a number of different events including loss of blood flow (ischemia), bleeding (hemorrhage), and the inability for blood to drain properly (venous thrombosis).

The most common type of stroke, and the type most people are referencing when they say “stroke,” is an ischemic stroke. This is also known as a cerebral infarction. Cerebral means brain and infarction means tissue death due to lack of blood flow. This type of stroke happens when a part of the brain doesn’t get enough blood flow. There are many, many ways this can happen but that topic deserves its own dedicated post. When a part of the brain goes without blood flow, the brain cells in that region can die. The area of the brain that dies is called a “stroke” or “infarction.”

Another fairly common type of stroke is known as an intracerebral hemorrhage. This is when a blood vessel ruptures inside the brain and causes bleeding inside the brain tissue. This bleeding is toxic to the brain cells and can cause them to die. The sheer mass and volume of the blood inside the brain can have devastating consequences and, in the most extreme cases, can cause brain death from brain herniation.

There is also a type of stroke known as a subarachnoid hemorrhage which is when a blood vessel ruptures and causes bleeding AROUND the brain, as opposed to inside of the brain. For a lot of reasons, this is actually one of the most deadly types of stroke.

There are other types of bleeding in the brain too, but these are generally not classified as strokes because they are the direct result of trauma to the head. These include subdural hematoma and epidural hematoma.

Another, less common type of stroke is called a cerebral vein thrombosis. It’s a very unusual stroke syndrome and most neurologists, including myself, don’t really think of it as a “stroke.” This happens when a vein that typically drains blood away from the brain becomes clogged because a blood clot has formed. This usually does not result in brain tissue death which is why most neurologists don’t consider it a “stroke.” However, if the blood flow problem continues without treatment for a prolonged period of time, an area of the brain may die resulting in a “venous infarction.” If this happens, then it is inarguably a stroke.

In the end, all of these stroke syndromes have very specific treatments. Furthermore, the most important aspect of treatment is finding out WHY the stroke happened in the first place. Once a cause can be found, it can be treated and/or reversed so that further strokes will not occur. There are hundreds of reasons why these stroke syndromes could occur and only a neurologist who has been highly trained in stroke has the knowledge to properly diagnose and treat stroke.

If anyone you know has been affected by stroke, please ensure that they were treated by a stroke-trained neurologist and that the specific causative agent for the stroke was found. If not, please set up a consultation with your local neurologist or call my office for an appointment.