Transient ischemic attack

Transient ischemic attack (TIA) 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, diplopia, 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 thrombophilia (acquired or inherited), or with antiplatelet therapy for nonembolic events. Modifiable risk factors such as carotid stenosis, hypertension, hyperlipidemia, and lifestyle are other targets of therapy.

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

A 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: a scientific statement for healthcare professionals from the American Heart Association/American Stroke Association Stroke Council; Council on Cardiovascular Surgery and Anesthesia; Council on Cardiovascular Radiology and Intervention; Council on Cardiovascular Nursing; and the Interdisciplinary Council on Peripheral Vascular Disease. The American Academy of Neurology affirms the value of this statement as an educational tool for neurologists. Stroke. 2009 Jun;40(6):2276-93. https://www.ahajournals.org/doi/full/10.1161/strokeaha.108.192218 http://www.ncbi.nlm.nih.gov/pubmed/19423857?tool=bestpractice.com [2]American College of Radiology. ACR appropriateness criteria: cerebrovascular diseases-stroke and stroke-related conditions​. 2023 [internet publication]. https://acsearch.acr.org/docs/3149012/Narrative ​​ The definitions of TIA and ischemic stroke are now "tissue-based" rather than defined by the duration of neurologic dysfunction: there is no ischemic lesion visible on brain imaging in a patient with TIA. An ischemic brain lesion on brain imaging, even if a patient's episode of focal neurologic dysfunction rapidly resolves, signifies an ischemic stroke.[3]Amarenco P. Transient ischemic attack. N Engl J Med. 2020 May 14;382(20):1933-41. http://www.ncbi.nlm.nih.gov/pubmed/32402163?tool=bestpractice.com 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.[4]Kidwell CS, Alger JR, Di Salle F, et al. Diffusion MRI in patients with transient ischemic attacks. Stroke. 1999 Jun;30(6):1174-80. https://www.ahajournals.org/doi/full/10.1161/01.str.30.6.1174 http://www.ncbi.nlm.nih.gov/pubmed/10356095?tool=bestpractice.com [5]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. https://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.