Types of Strokes
The Stroke Center at Scottsdale Healthcare Osborn Medical Center embraces a multidisciplinary collaboration that focuses on a patient and family-centered care approach to stroke victims and those at risk for stroke.
The Stroke Center provides consultation and evaluation of cerebrovascular- related issues, which include:
- Ischemic Strokes
- Hemorrhagic Strokes
- Transient Ischemic Attacks
- AVM (Arteriovenous malformation)
What is a stroke?
A stroke is an interruption of the blood supply to any part of the brain. Sometimes called a "brain attack," a stroke happens when blood flow to a part of the brain is interrupted because a blood vessel in the brain is blocked or bursts open. If blood flow is stopped for longer than a few seconds, the brain cannot get blood and oxygen. Brain cells can die, causing permanent damage.
A stroke is a medical emergency. Immediate treatment can save lives and reduce disability. Call 911 or seek immediate medical care at the first signs of a stroke. It is important to get to the emergency room immediately to determine if the stroke is due to bleeding or a blood clot so appropriate treatment can be started within 3 hours of when the stroke began.
Types of Stroke
Stroke can be caused by either a clot obstructing the flow of blood to the brain (ischemic) or by a blood vessel rupturing and preventing blood flow to the brain (hemorrhagic).
Ischemic stroke comprises the majority (87 percent) of all strokes. An ischemic stroke occurs when a blood vessel supplying blood to the brain is obstructed, thereby cutting off the supply of oxygen and nutrients. Ischemic strokes can either be embolic (due to a clot that migrated from another part of the body) or thrombotic (due to a clot that forms at the obstructed site). The underlying cause of this obstruction is the development of fatty deposits lining the vessel wall called atherosclerosis. Both types result in decreased blood flow to vital brain cells, which can lead to irreversible cell death and long-term disability.
Hemorrhagic stroke accounts for about 13 percent of stroke cases. It results from a weakened vessel that ruptures and bleeds into the surrounding brain. The blood then accumulates and compresses the surrounding brain tissue. This results in a stroke by depriving parts of the brain of blood and oxygen. There are two types of hemorrhagic stroke: intracerebral and subarachnoid.
- Intracerebral hemorrhage is the most common type of hemorrhagic stroke and occurs when a diseased blood vessel within the brain bursts and allows blood to leak within the brain. This causes an increase in pressure within the brain, which causes damage to the brain cells surrounding the blood. Hypertension is the primary cause of this condition. Risk factors include alcohol and drug abuse, increased age, being male and being African American.
- Subarachnoid hemorrhage occurs when a blood vessel just outside of the brain ruptures, causing the area of the skull surrounding the brain to rapidly fill with blood. It is usually caused when an aneurysm swells, weakens the vessel and ruptures. Risk factors include middle age, family history, smoking, excessive alcohol use, being female and African American.
Transient Ischemic Attack (TIA)
Transient ischemic attack, TIA, or a ministroke, is a brief episode of symptoms similar to those you'd have in a stroke. The cause of a transient ischemic attack is a temporary decrease in blood supply to part of your brain. Most attacks last just a few minutes.
TIA has the same cause as an ischemic stroke. In ischemic strokes, which are the most common type of stroke, a clot blocks the blood supply to part of your brain. But in contrast to a stroke, which involves a more prolonged lack of blood supply and causes some permanent damage to your brain tissue, a TIA doesn't leave lasting effects to your brain. Still, if you've had a TIA, it means there's likely a blocked or narrowed artery leading to your brain, putting you at a greater risk of a full-blown stroke that could cause more permanent damage. If you're having a TIA, get emergency medical treatment and make sure your regular physician knows about it.
Aneurysms are an abnormal widening or ballooning of a section of a blood vessel. When an aneurysm occurs in the brain, it is called a cerebral aneurysm. Aneurysms in the brain occur when there is a weakened area in the wall of a blood vessel. An aneurysm may be present from birth (congenital) or it may develop later in life. (For example, after a blood vessel is injured.) There are many different types of aneurysms.
AVM (Arteriovenous malformation)
AVM (Arteriovenous malformation) is an abnormal connection between the arteries and veins in the brain that usually forms before birth. The cause of a cerebral AVM is unknown. and the condition occurs when arteries in the brain connect directly to nearby veins without having the normal vessels (capillaries) between them. Cerebral AVMs occur in less than 1 percent of people.