What is the diagnostic workup for a Transient Ischemic Attack (TIA)?

From the Guidelines

The workup for a transient ischemic attack (TIA) should begin immediately with a thorough neurological examination, brain imaging with CT or MRI, and vascular imaging such as carotid ultrasound, CT angiography, or MR angiography to identify potential sources of emboli, as recommended by the most recent guidelines 1.

Initial Evaluation

The initial evaluation of a patient with a suspected TIA should include:

• Brain imaging with CT or MRI to rule out hemorrhage or other causes
• Vascular imaging such as carotid ultrasound, CT angiography, or MR angiography to identify potential sources of emboli
• Laboratory tests including complete blood count, coagulation studies, basic metabolic panel, lipid profile, and hemoglobin A1c
• Cardiac evaluation with an ECG to assess cardiac rhythm and identify atrial fibrillation or flutter or evidence of structural heart disease

Risk Factor Assessment

Risk factor assessment for hypertension, diabetes, smoking, and hyperlipidemia is crucial in the management of TIA.

• Patients with a history of hypertension, diabetes, or hyperlipidemia should be managed according to current guidelines
• Smoking cessation should be strongly encouraged

Treatment

Treatment typically begins with antiplatelet therapy such as aspirin 81-325mg daily, clopidogrel 75mg daily, or aspirin/dipyridamole extended-release.

• High-risk patients may benefit from admission for observation and expedited workup, as the risk of stroke is highest in the first 48 hours after a TIA
• Prolonged cardiac monitoring with Holter monitor or telemetry may be necessary to detect paroxysmal atrial fibrillation
• An echocardiogram may be indicated to identify cardiac sources of emboli

Recommendations

The most recent guidelines recommend that patients with suspected TIA should undergo an initial assessment that includes brain imaging, non-invasive vascular imaging, and 12-lead ECG and laboratory investigations 1.

• CT angiography including extracranial and intracranial vasculature from aortic arch to vertex is recommended as an ideal way to assess both the extracranial and intracranial circulation
• Vascular imaging is recommended to identify significant symptomatic extracranial carotid artery stenosis for which patients should be referred for possible carotid revascularization
• Carotid ultrasound and MR angiography are acceptable alternatives to CTA, and selection should be based on immediate availability and patient characteristics.

From the Research

Workup for Transient Ischemic Attack (TIA)

The workup for TIA involves a comprehensive evaluation to determine the cause of the ischemic episode and to assess the risk of subsequent stroke. The following steps are involved in the workup:

• Clinical diagnosis: A thorough medical history and physical examination are essential to diagnose TIA and to identify potential risk factors for stroke 2.
• Risk assessment: The use of risk stratification scales, such as the ABCD2 instrument, can help identify high-risk patients who require urgent evaluation and treatment 3.
• Imaging studies: Neuroimaging is critical in the evaluation of patients with TIA. CT and MRI are the two available options for imaging, with diffusion MRI being the recommended modality to image an ischemic lesion 4.
• Vessel imaging: Noninvasive vessel imaging, such as carotid Doppler ultrasound and CT angiography, may detect a symptomatic vessel lesion associated with an increased risk of stroke 4.
• Laboratory tests: Laboratory tests, such as complete blood count, blood chemistry, and coagulation studies, may be ordered to evaluate for potential causes of TIA, such as atrial fibrillation or carotid stenosis 5.
• Electrocardiogram (ECG): An ECG may be ordered to evaluate for cardiac causes of TIA, such as atrial fibrillation, and to assess for electrocardiographic changes associated with diabetes mellitus 6.

Management of TIA

The management of TIA involves urgent evaluation and treatment to reduce the risk of subsequent stroke. The following management strategies are recommended:

• Antiplatelet therapy: Dual antiplatelet therapy with aspirin and clopidogrel may be initiated within 24 hours of symptom onset and continued for 3 weeks to reduce stroke risk in select patients with high-risk TIA and minor stroke 3.
• Anticoagulation: Anticoagulation may be recommended for patients with atrial fibrillation or other cardiac sources of embolism 5.
• Carotid revascularization: Carotid revascularization may be recommended for patients with symptomatic carotid stenosis 3.
• Vascular risk factor reduction: Strategies to reduce vascular risk factors, such as hypertension, diabetes, and hyperlipidemia, are essential to reduce the risk of subsequent stroke 5.