Transcranial Doppler and Carotid Artery Disease Strokes: More Than Just Risk Stratification

Abstract

To the Editor: Two important studies addressing the role of transcranial Doppler ultrasound (TCD) microemboli detection and stroke prevention have been published recently.1,2 Markus and MacKinnon1 studied 200 patients within 3 months of a focal neurological event. Their study demonstrated that the presence of microembolic signals detected during 1 hour of TCD monitoring was an independent predictor of future stroke and transient ischemic attack (TIA). Two major implications were proposed, first that TCD emboli detection could be useful for risk stratification in patients with carotid stenosis and, second, that the technique could be used to assess the efficacy of antithrombotic therapy. In the recently published Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis (CARESS) trial,2 dual antiplatelet therapy (aspirin plus clopidogrel) resulted in more effective control of microembolic signals than single antiplatelet therapy (aspirin alone). There was an associated reduction in the subsequent prevalence of TIAs and strokes. Similar conclusions were drawn by the authors of both studies, in particular those patients with …