Workup for Lacunar Stroke
Yes, lacunar stroke requires the same comprehensive diagnostic workup as other ischemic stroke subtypes, despite its distinct pathophysiology, because potential cardioembolic sources and large-artery stenosis must be excluded to confirm the diagnosis. 1, 2, 3
Initial Acute Phase Imaging (<24 hours)
Essential First-Line Studies
- Non-contrast CT head is mandatory initially to exclude intracranial hemorrhage and evaluate for early ischemic changes, regardless of suspected stroke subtype 1
- Vascular imaging (CTA or MRA) must be obtained urgently to exclude large vessel occlusion, even when lacunar stroke is suspected clinically, because NIHSS scores correlate poorly with LVO presence 1
- MRI with diffusion-weighted imaging (DWI) is preferred over CT for detecting small subcortical infarcts <1.5 cm that define lacunar stroke 4
Key Diagnostic Principle
The diagnosis of lacunar stroke is one of exclusion—you cannot confirm it without ruling out other etiologies first 2, 3. The 2021 AHA/ASA guidelines define lacunar stroke as requiring both imaging confirmation of a small subcortical infarct AND absence of alternative causes 1.
Comprehensive Secondary Prevention Workup
Cardiac Evaluation Required
- Transthoracic echocardiography at minimum to assess for cardioembolic sources 1
- Transoesophageal echocardiography should be strongly considered, as cardiac sources of embolism significantly increase stroke recurrence risk in lacunar stroke patients (p=0.015 in multivariate analysis) 5
- Extended cardiac rhythm monitoring to detect paroxysmal atrial fibrillation 1
Vascular Assessment
- Carotid imaging (duplex ultrasound, CTA, or MRA) within 48 hours to exclude ipsilateral large-artery stenosis >50% 1, 2, 3
- This is critical because the presence of significant carotid stenosis would reclassify the stroke as large-artery atherosclerosis rather than lacunar 1
Laboratory Studies
- Lipid profile and hemoglobin A1c are essential components of the diagnostic assessment 1
- These identify modifiable risk factors particularly relevant to small vessel disease pathophysiology 6
Important Clinical Caveats
Why the Same Workup Matters
- Cardioembolism masquerades as lacunar stroke: Studies demonstrate that cardiac sources significantly affect long-term prognosis in patients initially presenting with lacunar syndromes 5
- Misclassification has therapeutic implications: A patient with atrial fibrillation and a small subcortical infarct requires anticoagulation, not just antiplatelet therapy 1
- Recurrent stroke risk is similar: Despite better early survival (85% at 2 years), lacunar stroke patients have comparable long-term recurrence rates to other stroke subtypes, necessitating thorough evaluation 2, 3, 6
Common Pitfall to Avoid
Do not assume a classic lacunar syndrome (pure motor hemiparesis, pure sensory stroke) automatically means small vessel disease etiology without completing the full workup 1, 2. The clinical syndrome alone is insufficient for diagnosis—imaging confirmation of infarct size and location plus exclusion of alternative causes is mandatory 3.
Unique Consideration for Lacunar Stroke
While the diagnostic workup is identical, the urgency differs slightly: lacunar strokes are less likely to benefit from mechanical thrombectomy since they don't involve large vessel occlusions, so the hyperacute rush for perfusion imaging may be less critical once LVO is excluded 1. However, this determination can only be made after obtaining vascular imaging, not before 1.