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Background and Purpose: Continuous-wave (cw)-Doppler sonography is a wellestablished noninvasive method for examining the extracranial vessels. It is extremely rare for an acute ischemic event to occur during cw-Doppler sonography of carotid stenosis. However, no data are available concerning the influence of mechanical stress connected with this procedure on the emboli rate distal to the stenosis.
Methods: The study involved 46 patients (28 men, 18 women) aged 66±10 years with an unilateral moderate (n=10) or severe (n=36) stenosis of the internal carotid artery (ICA). Twenty patients had a symptomatic stenosis and the remaining 26 were asymptomatic. Patients with other embolic sources, such as atrial fibrillation or mechanical heart valves, were excluded. All patients underwent bilateral emboli detection of the middle cerebral artery for a period of 29±8 minutes. In a second step, emboli detection (5±1 minutes) was performed simultaneously with cw-Doppler sonography of the carotid stenosis. Results: Seven of 46 patients (15%) had a median emboli rate of 5 emboli per hour distal to the carotid stenosis before the procedure. During cw-Doppler sonography of the carotid stenosis, 6 patients (13%) had a median emboli rate of 14 emboli per hour without clinical symptoms of cerebral ischemia. One patient had no change of the emboli rate and 2 patients showed a nonsignificant increase in emboli rate during cw-Doppler sonography. Three patients had no emboli before cw-Doppler sonography, but between 12 and 15 emboli per hour during the extracranial examination (P<.001). Conclusions: It must be presumed that patients with severe stenoses of the ICA represent a subgroup with fragile atheromatous plaques, which are more vulnerable to mechanical stress. The observations support the hypothesis that mechanical stress associated with routine ultrasound examinations of carotid stenosis may, in rare cases, evoke asymptomatic artery-to-artery embolism.
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- Transient ischemic attack resulting from carotid duplex imaging.Surgery. 1990; 107: 153-155
- Cerebrovascular events during carotid ultrasound.Eur J Ultrasound. 1997; 5 (abstr): 20
- Embolic stroke by compression maneuver during transcranial Doppler sonography.Stroke. 1994; 25: 1056-1057
- Carotid sinus massage and the risk of cerebral embolization.Stroke. 1995; 26: 1124-1125
- Stroke as a complication of carotid sinus massage.Crit Care Med. 1985; 13 (abstr): 869
- Cerebral atheromatous embolism following carotid sinus pressure.Arch Neurol. 1981; 38: 310-312
- Hemiplegia following carotid sinus stimulation.Am Heart J. 1946; 31: 131-137
- Incidence of complications after carotid sinus massage in older patients with syncope.J Am Geriatr Soc. 1994; 42: 1248-1251
- Monoplegia following carotid sinus massage.J Intern Med. 1994; 235: 379-381
- Silent cerebral embolism caused by neurologically symptomatic severe carotid stenosis.Brain. 1993; 116: 1005-1015
- Differentiation between gaseous and formed embolic materials in vivo.Stroke. 1994; 25: 1559-1563
- Detection of middle cerebral artery emboli during carotid endarterectomy using transcranial Doppler ultrasonography.Stroke. 1990; 21: 415-423
- Transcranial Doppler detection of circulating cerebral emboli.Stroke. 1993; 24: 1246-1250
- Detection of arterial emboli using Doppler ultrasound in rabbits.Stroke. 1991; 22: 253-258
- Basic identification criteria of Doppler microembolic signals.Stroke. 1995; 26: 1123
- A multicenter international study.Stroke. 1997; 28: 1307-1310
- Cerebral microembolism in symptomatic and asymptomatic high-grade internal stenosis.Neurology. 1994; 44: 615-618
- Clinical correlates of high-intensity transient signals detected on transcranial Doppler sonography in patients with cerebrovascular disease.Stroke. 1994; 25: 1570-1573
Accepted: November 24, 1997
Received: May 22, 1997
© 1998 National Stroke Association. Published by Elsevier Inc.