目的探讨脑缺血预适应(BIP)经颅多普勒(TCD)脑血流变化及对急性脑梗死(ACI)的影响。方法BIP观察短暂性脑缺血发作(TIA)病例,为A组(观察组)90例,其中A1组(TIA时长≤20分钟)45例,A2组(TIA时长>20min～≤60min)45例;同期随机抽取健康体检者为B组(对照组),45例。观察TIA者24小时内及同期对照组TCD脑血流变化及其后发生ACI的神经功能缺损评分。结果A组发ACI59例,B组发生ACI33例。A1组发生ACI前、后大脑中动脉(MCA)和基底动脉(BA)的平均血流速度(Vm)、搏动指数(PI)优于对照组,其后ACI神经功能缺损亦较对照组轻,有显著性差异(P<0.05);而A2组与对照组比,则均无明显差别(P>0.05)。结论持续适当的BIP,其Vm、PI优于无BIP者,并对其后发生的ACI能产生神经保护作用,早期TCD可帮助评估BIP病情及预后。 Objective To investigate the changes of transcranial Doppler (TCD) cerebral blood flow in cerebral ischemic preconditioning (BIP) and its effect on acute cerebral infarction (ACI). Methods Totally 90 cases of transient ischemic attack (TIA) were observed in group A (observation group). There were 45 cases in group A1 (TIA duration ≤20 minutes), 45 cases in group A2 (TIA> 20min ~ ≤60min) In the same period, healthy people were randomly selected as group B (control group), 45 cases. The changes of TCD cerebral blood flow and the ACI neurological deficit scores in TIA patients within 24 hours and in the same period were observed. Results A group of ACI59 cases, B group ACI33 cases. The average blood flow velocity (Vm) and pulsatility index (PI) of the MCA and BA in the A1 group before and after ACI were better than those in the control group, and the neurological deficits in ACI were also lighter than those in the control group. (P <0.05). There was no significant difference between A2 group and control group (P> 0.05). Conclusions Continuous appropriate BIP, Vm, PI better than no BIP, and subsequent ACI can produce neuroprotective effect, early TCD can help assess the BIP disease and prognosis.