A transient ischemic attack is a transitory attack of neurologic dysfunction affected by loss of blood flow such as focal brain, spinal cord or retinal with no delicate tissue death. As in the case of strokes, TIAs is similarly a disorder of cerebral blood flow. There are identical reasons for attacking in TIAs and strokes, as for example contras lateral paralysis or unexpected infirmity or lack of sensation. A cerebral infarct which continues more than 24 hours but less than 72 hours is called a reversible ischemic neurologic deficit or RIND.
Signs and symptoms:-
Depending on the vicinity of the brain involvement usually the warning sign may differ from man to man. Generally the normal indications contain transient loss of eyesight (normally amaurosis fugax); inconvenience speaking (aphasia); difficulty on one part of the body (hemiparesis); and lack of feeling or irritation (paresthesia), mostly on one segment of the body. Deterioration of awareness is very rare. There may be instances of interim and limited paralysis where face and tongue of the troubled person is disturbed. The indications of a TIA are momentary and generally continued from a few seconds to a few minutes and the majority of the indications depart within 60 minutes.
The general reason of a TIA is an embolus that occludes a vein in the brain. Due to atrial fibrillation, this normally crops up from a dislodged atherosclerotic plaque in one of the carotid veins or from a blood clot in the heart. There is no stable impairment as the obstruction time is very short in a TIA.
The development of cholesterol is slow and ultimately reduces the lumen. Gradually, blood flow to that part of the brain is decreased and the ultimate effect is stroke. In different cases, the cholesterol elements go into the brain unexpectedly detaching from the atherosclerotic plaque.