Microemboli as Marker of the Risk for Stroke

作者：Mess W H^*

来源：Klinische Neurophysiologie, 2010, 41(4): 258-262.

DOI：10.1055/s-0030-1265187

• transcranial Doppler sonography
• carotid artery stenosis
• carotid endarterectomy
• risk of stroke
• embolus detection

It is possible to detect microemboli in the middle cerebral artery using transcranial Doppler sonography. These microemboli are characterised by a short-lasting signal intensity increase (microembolic signal; "MES"), which is visible in the FFT spectrum and also depictable in the audio signal. MES detection is a robust method with a considerable interobserver agreement. MES can be seen in maximally half of the patients with a symptomatic carotid artery stenosis. The presence of MES implies a significantly increased risk of a renewed stroke or TIA and correlates with new lesions on MRI. Hence, the occurrence of MES allows for conclusions on the plaque properties and the effect of medical therapy. In future, the measurement of MES might result in a more adequate decision on carotid endarterectomy in a given patient. It holds also true for patients with an asymptomatic carotid artery stenosis that the presence of MES bears an increased risk of brain ischemia. In this group of patients MES are more difficult to detect due to their relatively infrequent occurrence and low intensity. However, the detection of MES in this patient group might considerably contribute to an adequate choice of therapy. In view of the currently available medical therapy, carotid endarterectomy cannot generally be recommended anymore. Possibly, those patients with MES might be an important exception. MES can also occur in relation to carotid endarterectomy. Those MES that can be detected during dissection as well as postoperatively show a correlation with neurological deficits. In the first case the carotid artery should be manipulated as little as possible, in the second case an intensified antithrombotic medication should be considered.

• 出版日期2010-12