抑郁症患者的认知功能、事件相关电位P300和MR扩散张量成像研究

目的 联合应用事件相关电位P300和MR扩散张量成像(DTI)研究抑郁症患者的认知功能损害,探讨抑郁症合并认知损害的机制. 方法 选取深圳市第二人民医院心理门诊自2008年5月至2009年9月接收的30例首发抑郁症患者作为抑郁症组,同期与抑郁症患者年龄、教育程度相匹配的健康志愿者30名做为对照组.应用威斯康星卡片分类测验(WCST)、P300检查和DTI扫描分别检测WCST各亚项得分、P3潜伏期和P3波幅、脑不同解剖部位的各向异性(FA)值.并对三者进行相关性分析. 结果 抑郁症组患者WCST各亚项得分、P3潜伏期和P3波幅与对照组相比较差异均有统计学意义(P<0.05);与对照组相比,抑郁症组患者双侧额叶、扣带回前部、扣带回压部、胼胝体膝部和压部FA值下降,差异有统计学意义(P<0.05);抑郁症组患者P3潜伏期与持续性错误数呈正相关关系(r=0.677,P=0.009),P3波幅与持续性错误数、不能维持完整分类数数均呈负相关关系(r=0.765,P=0.001;r=0.654,P=0.012),抑郁症组患者左、右侧额叶白质FA值分别与持续性错误数、不能维持完整分类数呈负相关关系(P<0.05). 结论 神经心理学和事件相关电位P300检查反映了抑郁症患者存在认知功能损害,P3潜伏期和P3波幅可作为认知功能的参考指标,DTI结果 揭示了抑郁症患者存在白质区域神经纤维的异常,这可能是抑郁症合并认知损害的神经病理学基础之一.

Correlation among cognition impairment, P300 value and MR diffusion tensor imaging data in patients with depression

Objective To investigate the cognition impairment in depression patients with its event-related potential P300 and MR diffusion tensor imaging (DTI) and explore the mechanism of depression combined with cognition impairment Methods We conducted a study of 60 people: 30 patients with depression and 30 healthy controls group-matched by age, educational level andsocioeconomic status. The latency period and amplitude of P3, and the data of fractional anisotropy (FA) were measured by P300 examination and DTI, respectively, in the bilateral white matter of interested region. Correlation analysis of these 3 factors was performed in the 2 groups. At the same time, the scores of Wisconsin card sorting test (WCST) were detected. Results The WCST scores of each sub-item,and the P3 latency and amplitude between the control group and depression group had statistically significant differences (P<0.05). FA value in the white matter of the both frontal lobe, the anterior cingulate gyms, the supramarginal gyrus, splenium of the corpus callosum in the patients was significantly lower than that in the controls (P<0.05). P3 latency and percentage of persistent errors in depression patients were positively correlated (r= 0.677, P=0.009). P3 amplitude and both percentage of persistent errors and percentage of not being able to maintain a complete classification were negatively correlated, respectively (r=0.765,P=0.001; r=-0.654, P=0.012). FA values and both percentage of persistent errors and percentage of not being able to maintain a complete classification were negatively correlated in patients with depression in the bilateral frontal white matter, respectively (left: r=-0.544,P=0.003; r=0.489, P=0.023; right: r=0.665, P=0.002; r=0.448,P=0.027). Conclusions Neuropsychology and event-related potential P300 reflected the cognition impairment in patients with depression; the latency period and amplitude of P3 could be a reference index of evaluating the cognitive function. The outcome of DTI can reveal the possible abnormality of neurofibra in the white matter region, which may be one of its neuropathology in depression patients with cognition impairment.