Microembolic Signals Detected by Transcranial Doppler Predict Future Stroke and Poor Outcomes

Abstract

Background and purpose: Although transcranial Doppler detects microembolic signals (MES) in numerous settings, the practical significance of such findings remains unclear.

Methods: Clinical information from ischemic stroke or transient ischemic attack patients (n = 248) who underwent embolic monitoring from January 2015 to December 2018 was obtained.

Results: MES were found in 15% of studies and ischemic recurrence was seen in 11% of patients (over 7 ± 6 days). Patients with MES had more lacunes than those without MES (1 ± 3 vs. 1 ± 2, P = .016), were more likely to have ischemic recurrence (37% vs. 6%, P < .001), undergo a future revascularization procedure (26% vs. 10%, P = .005), have a longer length of stay (9 vs. 4 days, P = .043), and have worse functional disability at discharge (modified Rankin Scale 3-6, 66% vs. 34%, P < .001). After controlling for several relevant cofactors, patients with MES were more likely to have ischemic recurrence (HR 4.90, 95% CI 2.16-11.09, P < .001), worse functional disability (OR 3.31, 95% CI 1.22-8.99, P = .019), and longer length of stays (β = .202, P < .001).

Conclusions: MES may help to risk stratify patients as their presence is associated with ischemic recurrence and worse outcomes.

Keywords: Neurosonology; cerebral emboli; recurrence; stroke; transcranial Doppler sonography.

Figure 1:

This figure demonstrates the ischemic recurrence-free probability stratified by the presence of microembolic signals (MES). Patients with MES had an increased recurrence-free probability compared to those without MES (p < 0.0001).

Figure 2:

This figure depicts the breakdown of modified Rankin Scale (mRS) scores of patients without microembolic signals (MES −) and patients with MES (MES +). Scores increase from left to right (ranging from 0 to 6), and the numbers within each box represent the percentage of patients with that particular mRS score.