What is the appropriate work‑up for a patient presenting with a suspected transient ischemic attack?

Work-Up for Suspected Transient Ischemic Attack

All patients with suspected TIA require immediate risk stratification based on symptom timing and type, followed by urgent brain imaging, vascular imaging from aortic arch to vertex, ECG, and laboratory studies—with the most critical distinction being whether symptoms occurred within 48 hours and involved motor weakness or speech disturbance, as these patients face a 1.5% stroke risk at 2 days and require emergency department evaluation within 24 hours. 1

Risk Stratification Determines Urgency and Setting

VERY HIGH Risk: Within 48 Hours + Motor/Speech Symptoms

• Patients presenting within 48 hours with unilateral weakness (face, arm, or leg) OR speech disturbance/aphasia must be sent immediately to an emergency department with advanced stroke capabilities. 1
• These patients have stroke recurrence rates of 1.5% at 2 days, 2.1% at 7 days, and 2.8% at 30 days with rapid intervention—compared to historical rates of 10.3% without immediate access to specialized care. 1
• The 7-day stroke risk can reach 36% in patients with multiple risk factors if not urgently evaluated. 1

HIGH Risk: Within 48 Hours Without Motor/Speech Symptoms

• Patients presenting within 48 hours with isolated hemibody sensory loss, monocular vision loss, binocular diplopia, hemifield vision loss, or ataxia should receive same-day assessment at a stroke prevention clinic or emergency department. 1
• These patients still require comprehensive evaluation within 24 hours of first healthcare contact. 1

MODERATE Risk: 48 Hours to 2 Weeks

• Patients presenting 48 hours to 2 weeks after symptom onset with motor weakness or speech symptoms require comprehensive evaluation within 24 hours of healthcare contact. 1
• Those without motor or speech symptoms (isolated sensory, visual, or coordination symptoms) should be evaluated within 2 weeks. 1

LOWER Risk: Beyond 2 Weeks

• Patients presenting more than 2 weeks after symptoms may be evaluated by a neurologist or stroke specialist within one month. 1

Required Diagnostic Investigations

Brain Imaging (Within 24 Hours for High-Risk Patients)

• CT or MRI of the brain must be completed within 24 hours for patients in the very high or high-risk categories. 1
• MRI with diffusion-weighted imaging is preferred as it detects silent cerebral infarctions in up to 31% of TIA patients, identifying those at highest risk for recurrence. 2, 3
• Brain imaging serves to exclude hemorrhage, identify acute infarction, and rule out stroke mimics. 3

Vascular Imaging (Within 24 Hours for High-Risk Patients)

• CT angiography from aortic arch to vertex should be performed at the time of initial brain CT to assess both extracranial and intracranial circulation. 1
• CTA is the preferred modality as it can be performed simultaneously with brain CT and visualizes the entire cerebrovascular tree including the posterior circulation. 1
• Carotid ultrasound and MR angiography are acceptable alternatives when CTA is unavailable or contraindicated, though selection should be based on immediate availability. 1
• Vascular imaging is critical to identify symptomatic carotid stenosis ≥70%, which requires urgent revascularization within 2 weeks. 1, 3

Cardiac Evaluation

• 12-lead ECG must be completed without delay in all suspected TIA patients to screen for atrial fibrillation and other cardioembolic sources. 1
• Prolonged cardiac monitoring (at least 24 hours of telemetry) is reasonable when the TIA etiology remains unclear after initial workup. 3, 4
• Echocardiography should be performed when a cardioembolic source is suspected based on clinical features or when vascular imaging does not reveal an alternative etiology. 5, 4

Laboratory Investigations

• Initial bloodwork should include: 1
  • Complete blood count
  • Electrolytes
  • Coagulation studies (aPTT, INR)
  • Renal function (creatinine, eGFR)
  • Random glucose or hemoglobin A1c
  • Troponin
• Subsequent testing should include: 1
  • Lipid profile (fasting or non-fasting)
  • Diabetes screening with fasting glucose, 2-hour glucose, A1C, or oral glucose tolerance test
  • ESR/CRP in patients over 50 years to rule out giant cell arteritis 3

Critical Pitfalls to Avoid

Do Not Delay for "Crescendo TIAs"

• Multiple, increasingly frequent TIA episodes mandate immediate hospitalization rather than any outpatient management. 2, 3
• These patients are at extremely high risk for imminent completed stroke. 2

Do Not Attempt Outpatient Workup for High-Risk Features

• Patients with symptomatic carotid stenosis >50%, known atrial fibrillation, or known hypercoagulable state require immediate inpatient evaluation. 2, 3
• Symptomatic carotid stenosis >50% carries a 90-day stroke risk approaching 20%. 3

Do Not Reassure Based on Symptom Resolution

• Approximately 70% of patients do not correctly recognize their TIA symptoms, and 30% of early recurrent strokes occur before patients seek medical attention. 6
• The transient nature of symptoms does not reduce stroke risk—half of all strokes after TIA occur within 48 hours of the initial event. 7

Recognize Red Flags for Carotid Dissection

• The combination of Horner-type ptosis (unilateral ptosis, miosis, anhidrosis) with contralateral headache is a red flag for carotid artery dissection, which can progress to complete stroke within hours. 3
• These patients require immediate CTA from aortic arch to vertex and consideration for anticoagulation after excluding hemorrhage. 3

Rapid-Access TIA Clinic Alternative

• If a certified rapid-access TIA clinic is available with immediate access to neuroimaging, vascular imaging, and stroke specialists, it can evaluate patients within 24-48 hours as an alternative to emergency department referral. 2, 3
• However, this option is only appropriate for lower-risk patients who do not meet very high or high-risk criteria. 3
• Rapid TIA clinic protocols have reduced 90-day stroke risk from 10.3% to 2.1% compared to delayed outpatient evaluation. 1, 2

Evidence Supporting Urgent Evaluation

The dramatic reduction in stroke recurrence rates with rapid evaluation protocols underscores the critical importance of urgent workup. Historical cohorts showed 90-day stroke risks of 12-20% after TIA, but modern rapid-access protocols have reduced this to 2.1-3.7% through immediate implementation of neuroimaging, antiplatelet therapy, statins, blood pressure management, and urgent carotid revascularization when indicated. 1, 7 Without urgent treatment, population-based studies continue to show 7-day stroke risks of 10-11%. 2, 3