Emergency medicine updates: Transient ischemic attack

Abstract

Introduction: Transient ischemic attack (TIA) is a condition commonly evaluated for in the emergency department (ED). Therefore, it is important for emergency clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

Objective: This paper evaluates key evidence-based updates concerning TIA for the emergency clinician.

Discussion: TIA is a harbinger of ischemic stroke and can result from a variety of pathologic causes. While prior definitions incorporated symptoms resolving within 24 h, modern definitions recommend a tissue-based definition utilizing advanced imaging to evaluate for neurologic injury and the etiology. In the ED, emergent evaluation includes assessing for current signs and symptoms of neurologic dysfunction, appropriate imaging to investigate for minor stroke or stroke risk, and arranging appropriate disposition and follow up to mitigate risk of subsequent ischemic stroke. Imaging should include evaluation of great vessels and intracranial arteries, as well as advanced cerebral imaging to evaluate for minor or subclinical stroke. Non-contrast computed tomography (CT) has limited utility for this situation; it can rule out hemorrhage or a large mass causing symptoms but should not be relied on for any definitive diagnosis. Noninvasive imaging of the cervical vessels can also be used (CT angiography or Doppler ultrasound). Treatment includes antithrombotic medications if there are no contraindications. Dual antiplatelet therapy may reduce the risk of recurrent ischemic events in higher risk patients, while anticoagulation is recommended in patients with a cardioembolic source. A variety of scoring systems or tools are available that seek to predict stroke risk after a TIA. The Canadian TIA risk score appears to have the best diagnostic accuracy. However, these scores should not be used in isolation. Disposition may include admission, management in an ED-based observation unit with rapid diagnostic protocol, or expedited follow-up in a specialty clinic.

Conclusions: An understanding of literature updates concerning TIA can improve the ED care of patients with TIA.

Keywords: Acute cerebrovascular syndrome; Deficit; Embolism; Ischemia; Neurology; Stroke; Thrombosis; Transient ischemic attack.