http://www.mayoclinic.com/health/transient-ischemic-attack/DS00220/METHOD=print
Mayo Foundation for Medical Education and Research
About one in three people who have a Transient Ischemic Attack (TIA), which is sometimes called a ministroke, eventually have a stroke, with about half occurring during the year after the TIA. You can control or treat a number of risk factors associated with TIAs.