In some cases, there is a smaller, temporary clot that may resolve itself quickly. The symptoms of a pre-stroke are often similar to a stroke because of the effect these clots have on the brain. A pre-stroke, also known as a transient ischemic attack, is often the warning sign of a potentially more severe stroke. If a physician detects that a person has experienced a pre-stroke, they may prescribe a thrombolytic drug that can reduce clotting and lower the risk of a more severe stroke occurring in the future.