Transient ischaemic attack: urgent investigation
The case
A 65-year-old man with type 2 diabetes and hypertension presents 3 hours after an episode of right arm weakness and slurred speech that lasted 20 minutes and has fully resolved. Examination is normal. Blood pressure is 148/92 mmHg and glucose 6.8 mmol/L. Non-contrast CT head is normal. His ABCD2 score is 6. What is the most appropriate next management step?
Options
- AMRI brain with diffusion-weighted imaging and MR angiography of the neck
- BDischarge with aspirin and GP review
- CClopidogrel and outpatient review
- DTransthoracic echocardiography
- EAmbulatory Holter monitoring
Think it through before you read on. Which single option is best, and why are the other four wrong?
Show the answer and explanation
Answer
A. MRI brain with diffusion-weighted imaging and MR angiography of the neck
Why this is the right answer
A transient ischaemic attack (TIA) is a warning of stroke. The risk is highest in the first 48 hours, and an ABCD2 score of 6 puts this man in the high-risk group, with roughly an 8–10% chance of stroke in the next 2 days.
The Australian stroke guidelines (Stroke Foundation) recommend that high-risk TIA patients are assessed and investigated urgently, ideally within 24 hours, and that this includes brain imaging and imaging of the carotid arteries [VERIFY]. A normal CT does not exclude infarction; MRI with diffusion-weighted imaging (DWI) finds small infarcts in a large proportion of clinical TIAs, which changes the diagnosis to stroke.
Carotid imaging matters because his symptoms (right arm, speech) point to the left carotid territory. If there is a significant carotid stenosis on the symptomatic side, carotid endarterectomy within 2 weeks gives the greatest stroke reduction.
Antiplatelet therapy is started at the same time, not instead of imaging. For high-risk TIA, a short course of dual antiplatelet therapy (aspirin plus clopidogrel for 3 weeks) is recommended, then single-agent therapy [VERIFY]. If atrial fibrillation is found, anticoagulation replaces antiplatelet therapy.
Echocardiography and Holter monitoring are part of the full work-up but come after the imaging that changes management most urgently.
Why the other options are wrong
- B
Discharging a high-risk TIA without urgent investigation leaves an 8–10% two-day stroke risk unaddressed.
- C
Antiplatelet choice depends on the cause; carotid disease and AF need different treatment.
- D
Echocardiography is part of the work-up but is not the most urgent test.
- E
Holter monitoring is done alongside or after brain and vessel imaging.
High-yield takeaway
High-risk TIA (ABCD2 4 or more) needs same-day MRI-DWI plus carotid imaging, with antiplatelet therapy started at once.
Reference: Stroke Foundation Australian and New Zealand Living Clinical Guidelines for Stroke Management, TIA section (2024)
Common questions
What ABCD2 score is high risk?
4 or more. This man scores 6 and has roughly an 8 to 10% risk of stroke in the next two days.
How soon must a TIA be investigated?
Same day, and ideally within 24 hours, with brain imaging and carotid imaging.
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