Suspected transient ischemic attack (TIA) or minor stroke is a relatively common presentation in emergency departments and primary care clinics. Secondary stroke prevention has evolved substantially over the last 20 years, such that the risk of stroke within 90 days of a TIA or minor stroke has fallen from 10% to as low as 1% with optimized and expedited management. (1-4)
The nomenclature surrounding TIA is inconsistent, which can cause confusion. However, 2 definitions are commonly used. One is based on time (i.e., symptom resolution within 24 hours), and the other is based on the appearance of tissue (i.e., no infarction on magnetic resonance imaging [MRI]). (5,6) A recent proposal has argued that it is not important to differentiate TIA from minor stroke, given their common pathophysiology, suggested investigations and management, when thrombolysis or thrombectomy are not indicated. (7) Acute ischemic cerebrovascular syndrome has been proposed as a term that includes both TIA and minor stroke.
Nomenclature aside, clinicians must distinguish cerebral ischemic events from stroke mimics (i.e., diagnoses that can resemble TIA or minor stroke), and begin stroke prevention measures in at-risk patients. (8,9) About half of initial diagnoses of TIA or minor stroke are ultimately diagnosed as a stroke mimic. (10)
Once patients are determined to have TIA or minor stroke, a series of investigations and assessments are needed to ascertain the cause as this determines management. Making an accurate diagnosis and identifying high-risk patients in a timely manner is critical to decrease the likelihood of a subsequent event. We discuss the investigation and management of acute ischemic cerebrovascular syndrome based on recent high-quality evidence, position statements and official guidance (Box 1).
How is transient ischemic attack or minor stroke diagnosed?
The diagnosis of TIA or minor stroke can be challenging and starts with taking a careful and focused history (Figure 1). Classically, a TIA or minor stroke presents with sudden onset of loss of function. Unilateral weakness, aphasia or dysarthria are strongly associated with a high likelihood of TIA or minor stroke. Symptoms are usually not progressive, repetitive, stereotyped or stepwise (e.g., starting in the face, then moving to the arm and then the leg). Although stuttering symptoms, whereby severity fluctuates over a few hours, can occur with small-vessel lacunar strokes, these would not be expected to last beyond 24 hours. Symptoms are usually negative rather than positive; for example, they involve the loss of vision rather than flashing lights, or the loss of feeling rather than electric shocks. Diagnosis is challenging when information is incomplete (e.g., because of language discordance or poor memory) or when patients present with a combination of typical and atypical features. (11) Recent studies suggest that clinicians may be less likely to diagnose TIA or minor stroke in women presenting with atypical symptoms than in men, although women have just as high a chance of having cerebral ischemia. (12,13) Even low-risk transient events may be associated with infarction on MRI; a recent cohort study found a rate of 13.5%. (14) Although some...