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Clinically silent circulating microemboli in 20 patients with carotid or vertebral artery dissection
D W Droste1, K Junker, F Stögbauer
1Department of Neurology, University of Münster, Germany. droste2@uni-muenster.de
Insights
Microembolic signals detected by transcranial Doppler sonography (TCD) indicate a higher risk of stroke recurrence in patients with acute carotid artery dissection or occlusion. These findings suggest a need for closer monitoring and potentially intensified antithrombotic therapy.
Area of Science:
- Cerebrovascular disease
- Neurology
- Vascular Surgery
Background:
- Cervical artery dissections, particularly carotid and vertebral artery dissections, are often complicated by cerebral embolism.
- Transcranial Doppler sonography (TCD) is being investigated for detecting clinically silent circulating microemboli in patients with carotid artery disease.
- The goal is to identify individuals at increased risk of stroke.
Purpose of the Study:
- To investigate the presence of microembolic signals using TCD in patients with carotid or vertebral artery dissection.
- To correlate microembolic signals with the severity and recency of cervical artery dissection.
- To assess the potential of microemboli detection for predicting stroke risk in these patients.
Main Methods:
- Twenty patients with carotid (n=17) or vertebral (n=2) artery dissection, or both (n=1), were enrolled.
- A 1-hour microembolus detection was performed using TCD downstream to the dissection site in the middle or posterior cerebral artery.
- Microembolic signals were quantified and analyzed in relation to stenosis degree and time since dissection onset.
Main Results:
- Microembolic signals (up to 15 events/h) were observed in five patients with > or = 90% carotid artery stenosis or occlusion.
- These positive findings were exclusively in patients with dissection onset within the last 58 days.
- No microembolic signals were detected in patients with lower stenosis degrees or symptom onset beyond 58 days. Three patients with recurrent ischemic events showed microembolic signals.
Conclusions:
- Microembolic signals are present in patients with high-grade stenosis or occlusion resulting from acute cervical artery dissection.
- The presence of microemboli suggests an increased risk of macroembolic events, such as stroke recurrence.
- Patients with detected microemboli may benefit from close clinical follow-up and potentially enhanced antithrombotic treatment strategies.
Background And Purpose:
Carotid and vertebral artery dissections are frequently complicated by cerebral embolism. Detection of clinically silent circulating microemboli by transcranial Doppler sonography (TCD) is now widely investigated in patients with carotid artery disease in the hope to identify patients at increased risk for stroke.
Methods:
In 20 patients with carotid (n = 17) or vertebral (n = 2) artery dissection, or both (n = 1), we performed a 1-hour microembolus detection downstream to the dissection in the middle or in the posterior cerebral artery, respectively.
Results:
Five patients with a carotid artery stenosis of > or = 90% or with carotid artery occlusion showed microembolic signals at a rate of up to 15 events/h. In all these patients, the onset of the dissection was within the last 58 days. Patients with lower degrees of stenosis or onset of symptoms beyond 58 days did not show microembolic signals at all. Three patients who had presented with recurrent ischaemic events prior to TCD monitoring unexceptionally had microembolic signals.
Conclusion:
Microembolic signals occur in patients with high-grade stenosis or occlusion due to acute cervical artery dissection. Patients with microemboli seem to be at increased macroembolic risk, i.e. stroke recurrence, and may require close-meshed clinical follow-up and possibly stronger antithrombotic treatment.