1. Understanding Stroke Slideshow Pictures
2. Take the Stroke Quiz
3. Atrial Fibrillation Slideshow: Causes, Tests and Treatment

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Daniel Lee Kulick, MD, FACC, FSCAI

Daniel Lee Kulick, MD, FACC, FSCAI

Dr. Kulick received his undergraduate and medical degrees from the University of Southern California, School of Medicine. He performed his residency in internal medicine at the Harbor-University of California Los Angeles Medical Center and a fellowship in the section of cardiology at the Los Angeles County-University of Southern California Medical Center. He is board certified in Internal Medicine and Cardiology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Transient ischemic attack (TIA) facts
• What is a transient ischemic attack (TIA)?
• What are the causes of transient ischemic attack (TIA)?
• What are the risk factors for transient ischemic attack (TIA)?
• What are the symptoms of transient ischemic attack (TIA)?
• How is transient ischemic attack (TIA) diagnosed?
• What is the treatment for transient ischemic attack (TIA)?
• What is the prognosis for transient ischemic attack (TIA)?
• Patient Comments: Transient Ischemic Attack (TIA, Mini-Stroke) - Symptoms
• Transient Ischemic Attack (TIA, Mini-Stroke) Index

The primary role of the brain is to send signals to the body for motor function and to receive signals through the five senses (sight, hearing, touch, smell, and taste), and to respond to them. The brain processes information through conscious thought, and unconsciously through nerve systems that control basic bodily functions, like heart rate, breathing, and temperature control.

In simple terms:

• The brain is arranged so that the right side of the brain controls the left side of the body, and the left side of the brain controls the right of the body.
• Vision is located in the back of the brain (occiput), and balance and coordination are located at the bottom of the brain (cerebellum).
• Blood supply to the brain comes from the carotid arteries that are located in the front of the neck, and the vertebral arteries that run in the back of the neck through small canals in the bony spine (vertebrae) of the neck.
• All of these connect at a junction of blood vessels located in the base of the brain (called the Circle of Willis), and from there smaller arteries supply the brain with oxygen and nutrients.

When a portion of the brain loses its blood supply, it can become damaged and stop functioning. When a portion of the brain does not function, the part of the body that it controls also stops working. This is called a stroke or a cerebrovascular accident (CVA). If the brain is able to regain its blood supply quickly, then the CVA symptoms may resolve; this is known as a transient ischemic attack (TIA). A TIA is similar to a stroke that resolves by itself because of a temporary lack of oxygen to a portion of the brain.

Loss of blood supply to portions of the brain can occur for a variety of reasons. A blood vessel can become blocked, and blood supply to a part of the brain is lost, or a blood vessel can leak blood into the brain (brain hemorrhage). Most commonly however, the blood vessel is blocked. The blockage can be caused by a blood clot that forms in the blood vessel (thrombosis) or it can be caused by a clot or debris that floats downstream (embolus).

Fatty plaque formation in the blood vessel wall is called atherosclerosis or "hardening of the arteries." Plaque can rupture and cause a small blood clot to form and occlude the blood vessel. Blockage can also occur when debris from narrowing of a carotid artery breaks off, and floats downstream to cause the occlusion. Sometimes, in people with an irregular heart beat called atrial fibrillation, small blood clots can be formed within the heart and travel to the brain to cause the obstruction.

Picture of Carotid Artery Disease and Plaque Buildup

Brain hemorrhage or bleeding in the brain can be due to an aneurysm, a weak spot in a blood vessel that ruptures and spills blood into the brain tissue, or it may be due to spontaneous bleeding caused by poorly controlled hypertension (high blood pressure). Such bleeding more commonly results in the irreversible damage of a stroke, as opposed to a TIA.