Clusters of Microembolic Signals: A New Form of Cerebral Microembolism Presentation in a Patient With Middle Cerebral Artery Stenosis

Segura, Tomás; Serena, Joaquı́n; Molins, A; Dávalos, Antoni

doi:10.1161/01.str.29.3.722

Cited by 25 publications

(22 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the chronic phase, Sliwka et al [6]could not detect MES in 58 patients with 78 MCA stenoses. Segura et al [7]described a patient with clusters of MES downstream to a recently symptomatic MCA stenosis.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Circulating Microemboli in 33 Patients with Intracranial Arterial Stenosis

Dw¹,

Junker²,

Hansberg³

et al. 2002

Cerebrovasc Dis

View full text Add to dashboard Cite

Background: Intracranial arterial stenosis is a rare cause of stroke in Caucasians. Detection of clinically silent circulating microemboli by transcranial Doppler sonography is now widely investigated in patients with carotid artery disease in the hope to identify patients at increased risk for stroke. Methods: In 33 patients with intracranial internal carotid (n = 12), middle cerebral (n = 18), posterior cerebral (n = 2), or basilar artery stenosis (n = 1), we performed a 1-hour microembolus detection downstream to the stenosis in the middle or in the posterior cerebral artery, respectively. The stenosis was assessed by transcranial Doppler and duplex ultrasound. 18 patients had been symptomatic in the dependent territory. Results: Five patients with ischaemic symptoms within the last 8 days and with a peak systolic flow velocity of ≧210 cm/s in the stenosis showed microembolic signals at a rate of 3–25 events/h, despite effective anticoagulation. All these 5 patients had a lesion pattern on cranial CT or MRI scan suggesting embolic origin. All the asymptomatic patients (n = 15) and all the patients with a peak systolic intrastenostic velocity of 160 to <210 cm/s (n = 13) did not show microembolic signals at all. Conclusion: Microembolic signals occur in recently symptomatic patients with high-grade intracranial arterial stenosis indicated by a sonographically measured stenotic peak flow velocity of ≧210 cm/s. Therapeutic anticoagulation was not sufficient to suppress microemboli formation.

show abstract

Section: Discussionmentioning

confidence: 99%

“…There are only three reports in the literature on the presence and frequency of MES in patients with intracranial stenoses [5, 6, 7]. …”

Section: Introductionmentioning

confidence: 99%

Circulating Microemboli in 33 Patients with Intracranial Arterial Stenosis

Dw¹,

Junker²,

Hansberg³

et al. 2002

Cerebrovasc Dis

View full text Add to dashboard Cite

show abstract

“…However, knowledge about embolism in patients with stenosis of the intracranial ICAs and MCAs is more limited. Recent studies show that HITS are often detectable in symptomatic patients with severe intracranial ICA and MCA stenosis [38,39,40]. Wong et al [38] used TCD to monitor for HITS in 114 patients with moderate or severe MCA stenosis diagnosed using MRA and TCD.…”

Section: Imaging and Ultrasound Monitoring Data Shows That The Prevalmentioning

confidence: 99%

“…Among symptomatic patients followed for an average of 13.6 months a significant association (log rank 5.96, p = 0.01) was found between the presence of HITS and further strokes [38, 39]. Segura et al [40] reported a patient with a high-grade MCA stenosis in whom ischemic symptoms correlated with clusters of HITS that occurred with a frequency of 8 clusters per hour with each cluster containing 12–45 microembolic signals.…”

Section: Imaging and Ultrasound Monitoring Data Shows That The Prevalmentioning

confidence: 99%

Is Hypoperfusion an Important Cause of Strokes? If So, How?

et al. 2006

View full text Add to dashboard Cite

Traditionally hypoperfusion and embolism are considered separate important causes of stroke in patients with arterial occlusive disease. However, although hypoperfusion and embolism differ in mechanisms and location, they generally coincide in severe obstructive lesions and cause washout disturbances of embolism in low perfusion territories distal to stenosis. Unless the collateral blood supply is sufficient to prevent ischemia, multiple remote spot-like infarctions occur within the hypoperfused brain territory. In border-zone distributed infarction – long suspected to result from hemodynamic compromise alone – complementary interaction of embolisation and hypoperfusion territories has to be considered. Thus hypoperfusion with embolism or embolism alone are the most common explanations for stroke, the former often associated with less severe clinical deficits than the latter.

show abstract

“…Nevertheless, others reported the coincidence of reduction rate of embolization in patients with acute stroke and therapy with warfarin plus antiplatelet [21] and, more recently, a paper reported the reduction of MES rate after receiving heparin in the acute phase of cardioembolic stroke [22] .…”

Section: Discussionmentioning

confidence: 99%