Transient ischemic attack (tia)

[Luis Fok]

A transient ischemic attack (TIA) is focal brain ischemia that causes sudden, transient neurologic deficits and is not accompanied by permanent brain infarction (eg, negative results on diffusion-weighted MRI). Diagnosis is clinical. Carotid endarterectomy or stenting, antiplatelet drugs, and anticoagulants decrease risk of stroke after certain types of TIA.
TIA is similar to ischemic stroke except that symptoms usually last lt; 1 hour; most TIAs last lt; 5 minutes. Infarction is very unlikely if deficits resolve within 1 hour. As shown by diffusion-weighted MRI and other studies, deficits that resolve spontaneously within 1 to 24 hours are often accompanied by infarction and are thus no longer considered TIAs.
TIAs are most common among middle-aged and older people. TIAs markedly increase risk of stroke, beginning in the first 24 hours.