Transient Ischemic Attack (TIA) called some people a mini-stroke, because the symptoms are like those of a stroke but do not last long. A transient ischemic attack (TIA) is an acute episode of temporary neurologic dysfunction resulting from focal cerebral ischemia not associated with permanent cerebral infarction. The clinical symptoms of TIA typically last less than an hour, but prolonged episodes can occur. While the classical definition of TIA included symptoms lasting as long as 24 hours, advances in neuroimaging have suggested that many such cases represent minor strokes with resolved symptoms rather than true TIAs.
A TIA happens when blood flow to part of the brain is blocked or reduced, often by a blood clot. After a short time, blood flows again and the symptoms go away. With a stroke, the blood flow stays blocked, and the brain has permanent damage. Brain cells require oxygen and glucose to function. If the blood supply is lost, then nutrient supply is lost, and the brain cells stop working.
The blood supply to brain cells can be lost in a few different ways.
- Blood clots can form in one of the tiny arteries of the brain (thrombosis). This is usually preceded by gradual narrowing of the blood vessel by fatty build-up called plaque. Atherosclerosis (atheroma=deposits of cholesterol and fatty tissue + sclerosis + narrowing) of the brain arteries is the same as the narrowing that occurs in heart arteries preceding a heart attack. A blood clot can form if the plaque ruptures, leading to further blockage of the artery.
- Blood clots can float downstream from the heart and get caught in a tiny blood vessel (embolus). Atrial fibrillation (A fib) is the most common reason for an embolus. In atrial fibrillation, the upper chambers of the heart jiggle and don’t beat in a coordinated fashion. This allows blood to become stagnant and form small clots. These clots can embolize to any organ in the body, but the brain is a common target.
- Debris can occlude the blood vessels and stop blood flow. This debris often breaks off from carotid arteries that are narrowed by the atherosclerotic disease process described above.
- Blood vessels can leak and cause bleeding within the brain tissue. An intracerebral hemorrhage (intra=within + cerebral= of the brain + hemorrhage=bleeding) is often caused by high blood pressure which can cause small blood vessel walls to become thin and weak.
Transient Ischemic Attack Successful Recovery
The main line of treatment after successful recovery from Transient Ischemic Attack should be to properly diagnose the cause and treat it accordingly. It is sometimes difficult to differentiate between TIA and stroke. The cause for the condition should be quickly established by imaging the brain. If the ECG reveals atrial fibrillation or arrhythmias or the Echo cardiogram shows thrombus in the heart chambers, anti coagulation medications can be beneficial.
The first line of treatment is administering aspirin, the next line is clopidogrel and the third one is ticlopidine. In case TIA re occurs even after aspirin treatment, a combination of dipyridamole and aspirin (Aggremox) may be prescribed. If the Transient Ischemic Attack affects any brain area which is supplied by carotid arteries, a TCD scan may reveal carotid stenosis.
In case a person has more than 70% stenosis in the carotid artery, the doctor may suggest removal of the atherosclerotic plaque through a surgical procedure or through a carotid endarterectomy. One complication which can occur during the surgical procedure is a stroke which may occur during or after the surgery. Some patients are given clopidogrel or modified release dipyridamole to reduce the chances of reoccurrence of such an attack. ACE inhibitors may also b administered, with an aim not to lower blood pressure too quickly as this may lead to ischemic injury because of low perfusion pressure.