a transient ischemic attack should be considered a major warning sign of an impending future stroke. up to 10% of people will experience a stroke within three months of a tia. since there is no way of predicting whether the next episode will resolve the patient needs to be educated that should symptoms occur they need to access medical care immediately. activating the emergency medical services system and calling 911 is recommended. if a stroke occurs there is a very short period of time where thrombolytic (clot dissolving) drugs [for example alteplase (tpa)] can be used to reverse a stroke. in most hospitals the drug can only be given within three hours of onset of stroke symptoms. in that three hours the patient needs to get to the hospital the diagnosis needs to be made laboratory tests and head ct scans need to be performed neurologic consultation needs to occur and the drug administered. the longer the delay the higher the risk that the drug won't work and that complications like bleeding into the brain will occur. specialized interventional radiologists can inject tpa directly into the clot that has blocked the blood vessel in the brain. this can extend the time frame to six hours but currently this treatment is not widely available. tias should be considered the equivalent of angina of the brain. in heart disease angina is the heart pain that warns of potential heart attack. when heart muscle is damaged it cannot be replaced or repaired. similarly brain tissue is at risk when there is decreased blood supply and it too cannot be replaced.
what is the prognosis for transient ischemic attack or tia?