Droste D W, Decker W, Siemens H J, Kaps M, Schulte-Altedorneburg G
Department of Neurology, Medical University Lübeck, Germany.
Neurol Res. 1996 Feb;18(1):25-30. doi: 10.1080/01616412.1996.11740372.
Albeit still unproven, it is supposed that the presence and number of asymptomatic circulating cerebral microemboli detected by transcranial Doppler ultrasound (TCD) may be an indicator of stroke risk. Little research has been done to assess the reproducibility of these data and the required time for recording. We examined one middle cerebral artery in 7 subjects with carotid, aortic or cardiac embolic source for 24 h by TCD. Analysis for embolic signals was done off line completely blinded to the diagnosis and the time of the day during the recording. Embolic signals were found in all 7 subjects varying from 0 per h to 13 per h. Embolic signals occurred throughout the day with a nonsignificant tendency towards higher values in the early morning hours. Half an hour recording would not have been suitable to rule out or to confirm the presence of embolic signals as there were too many gaps between embolic signals of more than 1/2 h. One hour is the required minimum. Concerning the number of embolic signals, even a recording of four hours yielded variabilities of 0.25 and 8 embolic signals per hour in the same person. We recommend to perform follow-up studies the same time of the day. In patients with a low number of embolic signals longer recordings or a lower detection threshold with a higher number of detected embolic signals are necessary to compare frequencies of embolic signals.
尽管仍未得到证实，但据推测，经颅多普勒超声（TCD）检测到的无症状循环脑微栓子的存在和数量可能是中风风险的一个指标。目前很少有研究评估这些数据的可重复性以及记录所需的时间。我们通过TCD对7名有颈动脉、主动脉或心脏栓子来源的受试者的一条大脑中动脉进行了24小时检查。对栓子信号的分析是在完全不知道诊断结果和记录期间一天中的时间的情况下离线进行的。在所有7名受试者中均发现了栓子信号，每小时的栓子信号数量从0个到13个不等。栓子信号在一天中均有出现，在清晨时段有数值较高的不显著趋势。半小时的记录不适合排除或确认栓子信号的存在，因为栓子信号之间有太多超过半小时的间隔。所需的最短记录时间为1小时。关于栓子信号的数量，即使是4小时的记录，同一个人每小时的栓子信号变化也在0.25个到8个之间。我们建议在一天中的同一时间进行后续研究。对于栓子信号数量较少的患者，需要更长时间的记录或更低的检测阈值以检测到更多的栓子信号，以便比较栓子信号的频率。
