摘要目的 研究血管性认知功能损害(VCI)患者事件相关电位P300亚成分P3a,P3b的变化特点,探讨其与认知功能及脑血流改变的关系.方法 对30例VCI患者及22例正常人进行P3a,P3b的检测,同时评定其认知功能,检查缺血病灶和脑血流情况,并进行相关性分析.结果 (1)VCI组的P3a潜伏期[(446±71)ms,(429±67)ms,(446±61)ms,(428 ±66)ms]、P3b潜伏期[(496±73)ms,(478±75)ms,(498±77)ms,(483±77)ms]在各记录区域均比正常组明显延长(P<0.01),P3a波幅在Fz[(3.3±2.6)μV]、Pz[(3.3±1.8)μV]点比正常组明显下降(P<0.01),P3b波幅[(4.5±2.5)μV,(6.4±3.8)μV,(5.3±3.8)μV,(5.3±3.0)μV]在各记录区域比正常组下降(P<0.01或P<0.05).(2)VCI组P3a、P3b潜伏期与注意力和MMSE总分成显著负相关(P<0.05或P<0.01),P3a、P3b波幅与MMSE总分和注意力、MMSE总分成显著正相关(P<0.05).(3)VCI组P3a潜伏期与额叶成显著正相关(P<0.05),P3b潜伏期与顶叶成显著正相关(P<0.05).(4)VCI组P3a潜伏期与RILMCA、RILACA和RIRACA成显著正相关(P<0.05或P<0.01).P3b潜伏期与RILMCA、RIRMCA和RIRACA成显著正相关(P<0.05或P<0.01),P3a波幅与RILACA成显著负相关(P<0.01).结论 P3a、P3b对于检测VCI患者的认知功能下降是一个较好的客观指标,可为其临床诊断提供参考依据.

abstractsObjective To investigate the characteristics of P3a and P3b which are the subcomponents of P300 event-related potential in patients with vascular cognitive impairment (VCI) ,and to investigate the relations between P3a,P3b and the changes of cognitive function and cerebral blood flow. Methods Thirty patients with VCI and twenty two normal subjects were tested for P3a and P3b cognitive function ischemic focus and cerebral blood flow and then analyzed for correlation. Results (1) The latency of P3a ((446 ± 71) ms, (429 ± 67) ms, (446±61)ms,(428±66)ms)and P3b((496 ±73)ms,(478 ±75)ms,(498 ±77)ms,(483 ±77)ms) was significantly prolonged in patients with VCI compared with that in normal subjects in all recorded regions(P<0.01) . The amplitude of P3a in patients with VCI ((3.3 ±2.6)μV,(3.3 ± 1.8)μV) was significantly lower than that in normal subjects in Fz and Pz (P<0.01) ,and the amplitude of P3b in patients with VCI((4.5 ±2.5)μV,(6.4 ± 3.8)μV,(5.3 ±3.8)μV,(5. 3 ±3.0)μV) was significantly lower than that in normal subjects in all recorded regions (P < 0.01 or P<0.05) . (2) The latency of P3a and P3b in patients with VCI was negatively related to the scores of sub items of attention and MMSE total scores (P < 0.05 or P < 0.01), the amplitude of P3a was positively related to the scores of MMSE total scores(P<0.05) ,the amplitude of P3b was positively related to the scores of attention and MMSE total scores(P<0.05). (3) The latency of P3a in patients with VCI was positively related to frontal lobe(P<0.05) ,and the latency of P3b was positively related to parietal lobe(P<0.05). (4) The latency of P3a in patients with VCI was positively related to RILMCA,RILACA and RIRACA(P<0.05 orP<0.01) ,the latency of P3b was positively related to RILMCA,RIRMCA and RIRACA(P<0.05 orP<0.01) ,and the amplitude of P3a was positively related to RILACA(P<0.01). Conclusion P3a and P3b are good objective indexes for testing the descent of cognitive function in patients with VCI,which can provide reference basis for the clinical diagnosis.