脑白质疏松症的血流动力学及局部脑血流变化的研究

目的　观察脑白质疏松症 (LA )血流动力学及局部脑血流量的变化 ,以探讨LA的发病机制。方法　对 6 7例LA患者行经颅多普勒 (TCD)检查 ,并对其中 19例患者行单光子发射计算机断层扫描 (SPECT)检查 ,观察局部脑血流 (rCBF)灌注情况。结果　轻、中、重 3组LA患者颈内动脉系统动脉平均峰值流速 (Vm)显著低于对照组 (P <0 0 5 ,P <0 0 1) ,重度LA组椎 基底动脉系统Vm显著低于对照组及轻度LA组 (P <0 0 5 ) ;轻、中、重 3组LA患者脉动指数 (PI)显著高于正常对照组 (P <0 0 1,P <0 0 0 1) ,中、重度组LA患者PI显著高于正常对照组及轻度组 (P <0 0 1,P <0 0 0 1)。SPECT检查发现LA患者灰质rCBF减少者为 5 2 6 % ,白质rCBF减少者为 78 9%。结论　LA患者存在广泛的脑血流低灌注和脑动脉硬化 ,并有随脑血流低灌注程度加重而LA病变加重的趋势 ,低灌注和脑动脉硬化是LA的主要发病机制。

Study on changes of hemodynamics and regional cerebral blood flow in patients with leukoaraiosis

Objective To observe changes of hemodynamics and regional cerebral blood flow(rCBF) in patients with Leukoaraiosis(LA) and to investigate the pathogenesis of LA.Methods 67 patients with LA were examined by Transcranial Doppler(TCD). Regional cerebral blood flow was detected by SPECT in 19 of 67 patients.Results The medium blood flow velocities(Vm) of internal carotid artery system in LA(included mild, moderate and severe group) were significantly decreased compared with the controls( P<0.05). The Vm of vertebral-basilar system in severe LA group was lower than those of the control group and the mild LA group( P<0.05). The pulse index(PI) in the three groups of LA were significantly higher than those of the controls( P<0.01), and the PI in moderate and severe LA groups were significantly higher than those of the control and the mild groups ( P<0.01). SPECT showed reduction of rCBF in gray matter in 52.6% of the patients, while in white matter in 78.9% of the patients.Conclusion Hypoperfusion and arteriosclerosis in the brain are extensive phenomenons in LA and they play important role in the pathogenesis of this disease. LA may deteriorate along with the decrement of brain hypoperfusion.