Diseases And Conditions

Transient ischemic attack (TIA)

A TIA or mini-stroke is a temporary loss of neurological function characterized by temporary difficulty or inability to speak, loss of sensation or movement on one side of the body or a facial droop. Other symptoms may include sudden loss of vision, double vision, inability to walk or severe dizziness. Symptoms may persist for up to 24 hours, and then clear suddenly or gradually.Estimates of the reported incidence of TIA vary from 200,000 to 500,000 yearly. TIAs are very significant medically because in many cases patients will go on to suffer an actual stroke in the near future. One third of patients with a TIA will go on to suffer a second TIA and one third of patients with TIA will go on to suffer a stroke within a month. It is estimated that when a stroke occurs after a TIA, patients may be left with neurological symptoms just as bad, as or worse than the TIA. Therefore, a TIA represents an important opportunity to diagnose and treat the cause of a potential stroke before the actual stroke occurs. As a result, a patient with TIA should be diagnosed and treated expeditiously, as there is only a limited window of opportunity in which to prevent a full-fledged stroke.TIAs are caused by the same things that cause a stroke. In 45% of cases, TIA is caused by a blockage in arteries either going to the brain or in the brain. 20% of the time, TIA is caused by clots in the heart, caused by a variety of conditions. Those clots may break off, traveling to the brain and causing a TIA. In 30% of cases, doctors may never discover the cause of TIA. Unusual causes, such as tearing of arteries, infection, clotting problems in the blood or migraines will lead to TIA in 5% of cases.The main difference between a TIA and a stroke is that in stroke, the blockage of the brain artery is permanent. This leads to permanent injury of brain. In TIA, the blockage of blood is temporary. If the blockage is relieved before death of brain cells occur, then brain function will be restored. When blood flow is restored, its either because the blockage opened up spontaneously or because brain arteries may have re-routed themselves, taking advantage of alternative routes in other arteries.

The most important thing about a TIA is treating the causes of a TIA before they lead to a stroke. If a TIA is caused by a blockage in the neck arteries supplying the brain (cervical arteries), than surgery or minimally invasive cervical stenting procedures can be used to open those arteries. When the larger arteries in the actual brain (intracranial arteries) are blocked, then intracranial stenting procedures can be employed. When stroke is caused by a blockage in the microscopic arteries of the brain medications that prevent clotting can be given. If a TIA is caused by clots in the heart or problems with a clotting in the blood then blood thinning medicines can be taken. Your doctor may recommend a number of tests to diagnose the cause of TIAs, like ultrasound of the neck or heart, blood tests, MRI of the brain or an angiogram. Whatever the cause of a TIA, identifying and treating risk factors such as smoking, high blood pressure, high cholesterol and diabetes will go far towards restoring health and lowering the chances of a subsequent stroke. This may involve significant lifestyle changes like exercising more, quitting smoking and having a healthier diet.