Definition for TIA
From Biology Forums Dictionary
A transient ischemic attack (TIA) is a transient episode of neurologic dysfunction caused by ischemia (loss of blood flow) – either focal brain, spinal cord or retinal – without acute infarction (tissue death)
TIA is caused by a clot; the only difference between a stroke and TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a relatively short time. Most TIAs last less than five minutes; the average is about a minute. When a TIA is over, it usually causes no permanent injury to the brain.