KEY POINTS
-
Patients with suspected cerebral ischemia should be evaluated urgently to distinguish between transient ischemic attack (TIA), mild stroke, or mimics such as migraine, seizures, vertigo, or syncope.
-
The Canadian TIA score can be used to determine early subsequent stroke risk in patients with suspected TIA or minor stroke.
-
All patients with TIA or minor stroke should undergo urgent electrocardiography and computed tomography of the head.
-
Clinicians should order early vascular imaging for patients at moderate or high risk for subsequent stroke; Urgent revascularization should be considered if there is greater than 50% arterial stenosis congruent with presenting symptoms.
-
Physicians should prescribe dual antiplatelet drugs for high-risk patients, single antiplatelet agents for low-risk patients, or direct oral anticoagulants for patients with atrial fibrillation.
-
All patients with TIA or mild stroke should receive counseling on modifiable lifestyle factors (including smoking cessation), be treated with statins, and take measures to optimize blood pressure, including treatment with antihypertensive drugs , if necessary.
Suspected transient ischemic attack (TIA) or mild stroke is a relatively frequent presentation in emergency departments and primary care clinics. Secondary prevention of stroke has evolved substantially over the past 20 years, so that the risk of stroke within 90 days after a TIA or mild stroke has dropped from 10% to 1% with management optimized and accelerated.1–4.
The nomenclature surrounding TIA is inconsistent, which can lead to confusion. However, 2 definitions are commonly used. One is based on time (ie, resolution of symptoms within 24 hours) and the other is based on tissue appearance (ie, no infarction on MRI). [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 treatment, when thrombolysis or thrombectomy are not indicated.7 The syndrome acute ischemic cerebrovascular disease has been proposed as a term that includes both TIA and minor stroke.
Apart from nomenclature, clinicians must distinguish cerebral ischemic events from stroke mimics (ie, diagnoses that may resemble TIA or mild stroke) and initiate stroke prevention measures in patients with risk.8,9 Approximately half of the initial diagnoses of TIA or minor stroke are finally diagnosed as a stroke mimic.10
Once patients have been determined to have a TIA or mild stroke, a series of investigations and evaluations are needed to determine the cause, as this determines management. Making an accurate diagnosis and identifying high-risk patients in a timely manner is critical to reducing the likelihood of a subsequent event. We discuss the research and management of acute ischemic cerebrovascular syndrome based on recent high-quality evidence, position statements and official guidance (Box 1).
Box 1: Evidence used in this review
We reviewed recent position statements for the investigation and management of transient ischemic attack (TIA) or minor stroke. These included the Canadian Stroke Best Practice Recommendations for the Secondary Prevention of Stroke Update 2020 and the American Heart Association’s 2021 Guideline for Stroke Prevention in Patients with Stroke and TIA . For articles describing specific mechanisms and treatments, we searched MEDLINE through February 2022, using terms such as “TIA,” “transient ischemic attack,” and “stroke.” We considered mainly original articles, but also review articles. In addition, we searched the reference lists of relevant articles to find other articles of interest.
How is a transient ischemic attack or mild stroke diagnosed?
Diagnosing TIA or minor stroke can be challenging and begins with taking a careful and focused history (Figure 1). Classically, a TIA or minor stroke presents with a 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 not usually progressive, repetitive, stereotyped, or staggered (eg, starting in the face, then moving to the arm, then to the leg). Although stuttering symptoms, in which the severity fluctuates over a few hours, can occur with lacunar small-vessel strokes, they are not expected to last more than 24 hours. Symptoms are usually negative rather than positive; for example, they involve loss of vision rather than flashing lights, or loss of sensation rather than electric shocks. Diagnosis is challenging when information is incomplete (eg, due to 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 to diagnose TIA or minor stroke in women who present with atypical symptoms than in men, although women are equally likely to have cerebral ischemia.12,13 Even low-risk transient events may be associated with a heart attack on MRI; a recent cohort study found a rate of 13.5%.14 Although some low-risk patients do have cerebral ischemia and could potentially benefit from early imaging, it is currently unclear what impact an MRI scan would have. more widespread magnetic in health costs and in the emergency service. crowding or subsequent stroke rates.
Figure 1:
Diagnosis and management of transient ischemic attack (TIA) or minor stroke. Note: ASA = acetylsalicylic acid, CT = computed tomography, ECG = electrocardiography.
Common mimics of TIA or minor stroke include migraine, peripheral vertigo, syncope, somatization, and seizures.10 The most common symptoms seen in patients with a common stroke include loss of consciousness, vertigo, bilateral symptoms, and confusion.10 Because the resources available to take risks with urgency. -stratify patients by the probability of subsequent stroke are limited, doctors should carefully consider other diagnoses before starting these investigations. Some hospitals routinely order an urgent MRI because the longer symptoms are present, the more likely acute ischemic changes will be present on MRI. However, the cost-benefit ratio and the impact of this strategy on subsequent stroke prevention are currently unknown.
How should a suspected transient ischemic attack or mild stroke be urgently investigated?
The period of greatest risk for subsequent stroke in patients with TIA or mild stroke is in the first few days after the initial event; the average time is 24 hours.15 Therefore, investigations must be done in hours.
Risk stratification
Various scoring systems can be used to identify high-risk patients and guide the prioritization of tests and specialist evaluation. The Canadian TIA score (Figure 2) has been derived and validated in 2 large, multicenter cohort studies to accurately stratify patients with TIA or minor stroke as low, intermediate, or high risk for subsequent stroke within 7 days. 16,17. Low-risk patients have a risk of less than 1%, medium-risk patients have a 1% to 5% risk, and high-risk patients have a greater than 5% risk of stroke later in 7 days. A reasonable clinical approach is to arrange urgent vascular imaging for intermediate- and high-risk patients and to discuss high-risk patients with a stroke specialist during their initial evaluation. Most low-risk patients can be treated as outpatients.
Figure 2:
The Canadian Transient Ischemic Attack (TIA) Score.16 Note: BP = blood pressure, CT = computed tomography, ECG = electrocardiography, ED = emergency department.
The Canadian TIA score contains 13 clinical or core research variables that are assigned different weights. Free calculators are available through phone apps, such as the Ottawa Rule app, to help doctors. The Canadian TIA score outperformed both the ABCD2 (age, blood pressure, clinical characteristics, duration of symptoms and diabetes) and ABCD2i (age, blood pressure, clinical characteristics, duration of symptoms, diabetes and infarction) scores, which are relatively simple and widely recognized tools (absolute net reclassification index, which quantifies how well a new model reclassifies cases compared to an old model, 12.0% and 8.5% on ABCD2 and ABCD2i, respectively; 16.3% of patients classified as low risk with the Canadian TIA score v). 0% classified as low risk using ABCD2 or ABCD2i).16
Neuroimaging
Urgent brain imaging is critical for the evaluation of patients with TIA or minor stroke. The Canadian stroke best practice guideline calls for non-contrast computed tomography (CT) of the head to be performed immediately in all patients with TIA or minor stroke to assess for stroke mimics and to help determine the risk of subsequent stroke.8 A multicenter cohort study of 1028 patients determined that patients with CT abnormalities (an acute cerebral infarction alone, an older acute infarction, or an acute infarction, an older infarct, and microangiopathy ) have a 90-day risk of subsequent stroke that is 3-, 11-, and 24-fold greater than those with a normal CT, respectively.18 Because the sensitivity of CT for TIA or stroke minor is low, MRI provides additional information, but is not readily available in many Canadian centers.14 Given a relative lack of MRI availability and clear evidence on the impact of routine MRI, we suggest uti licate the modality that is locally available for neuroimaging, which will be CT in most places.
Vascular imaging
Vascular imaging of the neck and brain may identify extracranial carotid stenosis, intracranial or posterior circulation stenosis, acute thrombus, or cervical artery dissection. It is vital to identify patients with greater than 50% stenosis of the extracranial carotid artery with CT angiography or Doppler ultrasonography, as they are at increased risk of subsequent posterior stroke. stroke mimic as the cause of your symptoms, it is not a good use of resources to urgently seek…