Wednesday, October 22, 2014
TIA or true stroke
How can you tell the difference between a TIA and a stroke?
A TIA and a stroke are both related to a blood clot blocking a blood vessel that supplies the brain. During the time when the blood clot is present, the part of the brain fed by that blood vessel is not getting any oxygen and is thus "suffocating" in a sense. The brain cells fed by that blocked blood vessel will "die" (be irreversibly injured) if blood flow is not restored. During the time when the blood clot is blocking flow, the patient has symptoms related to the area of the brain not getting oxygen. For example, if the blood clot is preventing blood flow to the part of the right brain which controls movement of the left side of the body, the patient will have paralysis of the left side of the body.
Blood clots that block flow can dissolve on their own. If they dissolve quickly, before permanent damage can occur, it is called a transient ischemic attack or TIA. In this case, the patient's symptoms go away when the blood clot dissolves. TIA's typically last minutes, although they can last hours. By definition, we call an event a TIA if the neurologic symptoms go away completely within the first 24 hours.
A stroke is when the blood clot does not dissolve, resulting in permanent injury to the brain. The patient is left with symptoms that last more than 24 hours.
I hope this answers your question.
Brett Kissela, MD
Assistant Professor of Neurology
Director, Neurology Residency Program
College of Medicine
University of Cincinnati