A transient ischemic attack (TIA) is an episode of stroke-like symptoms. It usually lasts less than one hour. A TIA is sometimes called a ministroke.
During a TIA, circulation to a part of the brain is interrupted briefly, then restored. This interruption can be caused by:
A narrowing of a brain artery because of atherosclerosis.
A small floating blood clot. This clot enters the bloodstream from somewhere else in the body, often the heart. It temporarily blocks a brain artery.