Microembolic signals after 7 days but not within 24 hours of stroke onset should be predictor of stroke recurrence
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Published on: September 25, 2019
Yasuyuki Iguchi1, Kazumi Kimura, Kazuto Kobayashi
1Department of Stroke Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan. yigu@med.kawasaki-m.ac.jp
Background And Purpose:
Microembolic signals (MES) on transcranial Doppler ultrasonography (TCD) are occasionally detected in acute ischemic stroke patients and gradually decrease over time. If MES is detectable at 7 days after stroke onset, embolic source lesions may still be active. We hypothesized that presence of MES at 7 days after stroke onset is strongly associated with stroke recurrence.
Methods:
Subjects comprised 143 patients with acute ischemic stroke who were prospectively examined for the presence of MES using TCD both within 24 h and at 7 days after stroke onset. Stroke recurrence was assessed within 3 months of stroke onset. The association between presence of MES and stroke recurrence was investigated.
Results:
MES was detected in 70 of 143 patients (49%) within 24 h of stroke onset and in 34 patients (24%) at 7 days. Stroke recurrence was observed in 6 patients after 7 days and in 10 patients between 7 days and 3 months after stroke onset. Presence of MES within 24 h of stroke was not associated with stroke recurrence (10% for MES-positive vs. 12% for MES-negative, p=0.792). At 7 days after onset, stroke recurrence was more frequent in the MES-positive group at 7 days than in the MES-negative group (24% vs. 7%, p<0.0001). Cox's proportional hazard analysis demonstrated presence of MES as an independent factor of stroke recurrence (hazard ratio, 6.4; 95% confidence interval, 1.4-28; p=0.015).
Conclusion:
Presence of MES detected on TCD at 7 days of stroke onset should be a predictor of stroke recurrence.
Insights
Microembolic signals (MES) detected by transcranial Doppler (TCD) at 7 days post-stroke indicate ongoing embolic activity. This presence of MES is a strong predictor of recurrent stroke within three months.
Area of Science:
- Neurology
- Neuroimaging
- Stroke Medicine
Background:
- Microembolic signals (MES) on transcranial Doppler (TCD) are observed in acute ischemic stroke patients.
- These signals typically decrease over time, but persistence may indicate active embolic sources.
Purpose of the Study:
- To investigate the association between the presence of MES at 7 days after stroke onset and the risk of stroke recurrence.
- To determine if MES detected at 7 days is an independent predictor of stroke recurrence.
Main Methods:
- Prospective study of 143 acute ischemic stroke patients.
- MES detection using TCD within 24 hours and at 7 days post-stroke.
- Assessment of stroke recurrence within 3 months.
Main Results:
- MES was detected in 49% within 24 hours and 24% at 7 days.
- MES presence at 24 hours was not associated with recurrence (p=0.792).
- MES at 7 days was significantly associated with higher recurrence rates (24% vs. 7%, p<0.0001) and identified as an independent predictor (HR 6.4, p=0.015).
Conclusions:
- Persistent microembolic signals detected by TCD at 7 days after stroke onset are a significant predictor of stroke recurrence.
- This finding highlights the clinical utility of TCD in identifying patients at high risk for secondary events.
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