**4.4 TCD can identify clinically silent emboli: microembolic signals (MES), which recognizes patients at higher risk of embolic stroke**

MES detection in different interventional procedures (cerebral and coronary angiography, angioplasty, carotid endarterectomy, etc.) and in patients with extra and intracranial large artery atherosclerotic stenosis is useful in risk stratification, thus enabling to select those patients who could benefit from a more aggressive treatment [33, 41, 47]. MES detection requires continuous monitoring (at least 1 hour) of the major intracranial arteries. Most MES can be detected several days after the embolic event. The origin of emboli is important; the detection of an embolic signal in the distal MCA might represent an atherosclerotic plaque in the ipsilateral MCA or ICA. On the other hand, the identification of MES in multiple bilateral arteries indicates a cardiac origin [33, 41, 47].
