Embolic signals and prediction of ipsilateral stroke or transient ischemic attack in asymptomatic carotid stenosis: a multicenter prospective cohort study.

Background And Purpose: We tested the hypothesis that transcranial Doppler embolic signal (ES) detection identifies an increased risk of ipsilateral carotid stroke or transient ischemic attack (TIA) in subjects with asymptomatic severe carotid stenosis.

Methods: Subjects with duplex-determined 60% to 99% carotid stenosis, without other apparent cerebroembolic sources, underwent 6-monthly neurological assessment and 60-minute ES monitoring. ES positivity was defined as > or =1 ES detected in > or =1 study, ES negativity as no ES in any study, and consistent ES negativity as no ES in any study where > or =6 studies were performed.

High intensity transient signals in patients with carotid stenosis may persist after carotid endarterectomy.

Background: This study was undertaken to elucidate the natural history of high intensity transient signals (HITS) after carotid endarterectomy (CEA) and to determine whether this differs between patients with and without HITS detected preoperatively.

Methods: A 30-min transcranial Doppler (TCD) recording was performed to detect HITS in 141 patients at 0-1 h, 2-3 h, 4-6 h and 24-36 h following CEA. 104 of these patients also had 30-min TCD monitoring within 48 h prior to CEA.

Possible determinants of early microembolism after carotid endarterectomy.

Background And Purpose: High numbers of microembolic signals (MES) have been associated with increased risk of postoperative stroke after carotid endarterectomy (CEA). We sought to identify factors predictive of postoperative MES.

Methods: Transcranial Doppler monitoring of the ipsilateral middle cerebral artery for MES was performed for 30 minutes during the first postoperative hour in sequential patients undergoing CEA.

Source of microembolic signals in patients with high-grade carotid stenosis.

Background And Purpose: In patients with both symptomatic and asymptomatic carotid artery stenoses, the relationship between carotid plaque characteristics and transcranial Doppler (TCD)-detected microembolic signals (MES) is unclear. The purpose of this study was to examine the relationship between macroscopically described plaque characteristics and MES in patients undergoing carotid endarterectomy.

Methods: Sequential patients scheduled for carotid endarterectomy underwent preoperative 30-minute TCD monitoring of the ipsilateral middle cerebral artery to detect MES.