Droste D W, Dittrich R, Kemény V, Schulte-Altedorneburg G, Ringelstein E B
Department of Neurology, University of Münster, Germany.
J Neurol Neurosurg Psychiatry. 1999 Oct;67(4):525-8. doi: 10.1136/jnnp.67.4.525.
Besides the established factors "presence of symptoms" and "degree of stenosis", plaque echolucency is considered to be associated with increased risk of stroke in patients with carotid artery disease. An evaluation was carried out as to whether the prevalence and number of microembolic signals (MES) detected by transcranial Doppler ultrasound were higher in patients with echolucent carotid plaques. One hundred and five patients with carotid artery stenosis from 20%-99% or occlusion underwent clinical investigations, duplex ultrasound of the carotid arteries, and a 1 hour recording from the middle cerebral artery downstream to the carotid artery pathology using the four gate technique. The presence of MES was more frequent and the number greater in symptomatic patients (21 out of 64 patients (33%); mean number of MES in all 64 patients 3.1) than in asymptomatic patients (four out of 41 patients (10%); mean number of MES in all 41 patients 0.3) (p=0.007, and p=0.006, respectively). Echogenicity of the lesions did not affect either number or presence of MES. Positivity for MES and the number of MES increased with increasing degree of stenosis (both p=0.002). Four out of 12 patients with carotid artery occlusion showed MES. No MES could be detected in carotid artery stenosis below 80%. There was a decline in positivity of MES and of the number of MES with the time after the ischaemic event. After 80 days or more after the index event, only one patient showed MES. In conclusion, increasing degree of stenosis and presence of symptoms similarly affect macroembolic and microembolic risk. Thus MES may be a surrogate parameter for risk of stroke. The presence of MES in a few asymptomatic patients suggests that clinically silent circulating microemboli may give additional information on the pending embolic potential of carotid artery stenoses. Echolucency of the plaque was not related to an increased number of MES.
除了已确定的因素“症状的存在”和“狭窄程度”外，斑块回声性被认为与颈动脉疾病患者中风风险增加有关。针对颈动脉低回声斑块患者经颅多普勒超声检测到的微栓子信号（MES）的发生率和数量是否更高进行了一项评估。105例颈动脉狭窄20%-99%或闭塞的患者接受了临床检查、颈动脉双功超声检查，并使用四通道技术对大脑中动脉下游至颈动脉病变进行了1小时的记录。有症状患者（64例患者中有21例（33%）；所有64例患者的MES平均数量为3.1）中MES的出现比无症状患者（41例患者中有4例（10%）；所有41例患者的MES平均数量为0.3）更频繁且数量更多（分别为p=0.007和p=0.006）。病变的回声性对MES的数量或出现均无影响。MES阳性率和MES数量随狭窄程度增加而增加（两者p=0.002）。12例颈动脉闭塞患者中有4例显示有MES。在低于80%的颈动脉狭窄中未检测到MES。MES阳性率和MES数量随缺血事件后的时间而下降。在索引事件后80天或更长时间后，只有1例患者显示有MES。总之，狭窄程度增加和症状的存在同样影响大栓子和微栓子风险。因此，MES可能是中风风险的替代参数。少数无症状患者中MES的存在表明临床上无症状的循环微栓子可能提供有关颈动脉狭窄潜在栓子形成可能性的额外信息。斑块的回声性与MES数量增加无关。
