Transient ischemic attack

Cerebral ischemia should be suspected when a patient presents with typical symptoms of rapidly resolving unilateral weakness or numbness, but also with less classic symptoms such as unilateral vision loss, transient aphasia, or vertigo.

In a patient who presents with ongoing neurologic deficit, aggressive treatment for stroke should not be delayed in the hope that the symptoms will spontaneously resolve.

TIAs have considerable risk of early recurrent cerebral ischemic events. Evaluation and initiation of secondary prevention should occur rapidly.

Evaluation focuses on workup of underlying etiology. Treatment hinges on secondary prevention with anticoagulants in cases of embolic etiology, or antiplatelet therapy for nonembolic events. Modifiable risk factors such as carotid stenosis, hypertension, hyperlipidemia, and unhealthy lifestyle are other targets of therapy.

In addition to a complete neurologic exam and evaluation for diseases that mimic TIA, diagnostic imaging such as MRI with diffusion-weighted images may be helpful to detect evidence of subclinical cerebral infarction.

A transient ischemic attack (TIA) is a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction. [1] Easton JD, Saver JL, Albers GW, et al. Definition and evaluation of transient ischemic attack. Stroke. 2009;40:2276-2293. http://stroke.ahajournals.org/content/40/6/2276.full http://www.ncbi.nlm.nih.gov/pubmed/19423857?tool=bestpractice.com This replaced the former definition of focal neurologic impairment lasting less than 24 hours. The majority of TIAs resolve within the first hour, and diagnostic imaging allows recognition that some events with rapid clinical resolution are associated with permanent cerebral infarction. [2] Kidwell CS, Alger JR, Di Salle F, et al. Diffusion MRI in patients with transient ischemic attacks. Stroke. 1999 Jun;30(6):1174-80. http://stroke.ahajournals.org/content/30/6/1174.full http://www.ncbi.nlm.nih.gov/pubmed/10356095?tool=bestpractice.com [3] National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Tissue plasminogen activator for acute ischemic stroke. N Engl J Med. 1995 Dec 14;333(24):1581-7. http://www.nejm.org/doi/full/10.1056/NEJM199512143332401 http://www.ncbi.nlm.nih.gov/pubmed/7477192?tool=bestpractice.com The arbitrary definition of duration of symptoms for TIA should not deter aggressive therapy for a patient who presents with new neurologic deficit.