Detection of microembolic signals with transcranial Doppler ultrasound.

Detection of microembolic signals (MES) with transcranial Doppler was introduced in the late 1980s; several animal and in vitro models reported a high sensitivity and specificity with this technique. Monitoring for MES in various patient groups has provided valuable insights on stroke pathophysiology, although its clinical value remains a matter of debate. Diagnosis of imminent occlusion of the internal carotid artery following carotid endarterectomy, selection of high-risk patients with asymptomatic carotid disease, and evaluation of drug efficacy constitute potential applications of this technique.