Halsey J H, McDowell H A, Gelmon S, Morawetz R B
Department of Neurology, University of Alabama Medical Center, Birmingham.
Stroke. 1989 Jan;20(1):53-8. doi: 10.1161/01.str.20.1.53.
Blood flow velocity in the middle cerebral artery, determined by transcranial Doppler ultrasonography, was monitored during 31 carotid endarterectomies. Electroencephalogram (EEG) was also monitored, and regional cerebral blood flow (rCBF) was measured. The relation between rCBF and mean velocity was dependent on the rCBF level; the correlation was strong if rCBF was less than 20 ml/100 g/min but weak if rCBF was greater than that level. Ipsilateral EEG suppression was related to a rCBF threshold of 9 ml/100 g/min and to a mean velocity threshold of 15 cm/sec; the rCBF threshold was more specific for EEG change. Postischemic hyperemia was evident in measurements of mean velocity but not of rCBF. These disparities between mean velocity and rCBF seemed to be due to three factors: 1) disproportionately high mean velocity in patients with stenosis of the middle cerebral artery, 2) a nonlinear relation between mean velocity and rCBF, and 3) the anatomically different regions of the brain in which mean velocity and rCBF are measured. The velocity measurement appeared to be relatively more sensitive than rCBF to hemodynamic events in the corpus striatum and internal capsule.
在31例颈动脉内膜切除术过程中，通过经颅多普勒超声监测大脑中动脉的血流速度。同时监测脑电图（EEG），并测量局部脑血流量（rCBF）。rCBF与平均速度之间的关系取决于rCBF水平；当rCBF小于20 ml/100 g/min时相关性很强，但当rCBF大于该水平时相关性较弱。同侧EEG抑制与rCBF阈值9 ml/100 g/min和平均速度阈值15 cm/sec有关；rCBF阈值对EEG变化更具特异性。缺血后充血在平均速度测量中明显，但在rCBF测量中不明显。平均速度与rCBF之间的这些差异似乎归因于三个因素：1）大脑中动脉狭窄患者的平均速度异常高，2）平均速度与rCBF之间的非线性关系，3）测量平均速度和rCBF的大脑解剖区域不同。速度测量似乎比rCBF对纹状体和内囊的血流动力学事件相对更敏感。
