抑郁症首次发作患者视觉空间认知的功能偏侧化研究

Hemispheric dominance on visuo-spatial cognitive function in patients with first-episode depression

目的探讨首发抑郁症患者视觉空间认知的左右大脑半球的功能偏侧化。方法对35例首发抑郁症患者(患者组)和36名健康志愿者(对照组)进行视觉空间旋转任务的事件相关电位测定,并对其脑分布地形图的变化进行了对照观察。结果①与对照组相比,患者组平均错误率显著升高[(22.3±6.5)%vs(18.4±5.6)%],平均反应时显著延长[(761.4±94.2)ms vs(634.7±84.9)ms,P<0.05];患者组正像、镜像错误率、反应时差异不显著(P>0.05)。②与对照组正像、镜像P500相比,患者组波幅P4正像显著降低[(7.63±2.63)μV vs(9.58±3.22)μV],镜像显著升高[(6.90±1.92)μV vs(4.95±1.92)μV,P<0.05],患者组自身正像、镜像兴奋性差异均消失;左右大脑相比,患者组正像右顶枕叶兴奋性显著升高(P<0.05),而镜像兴奋性差异不显著(P>0.05),对照组正像、镜像右顶枕叶兴奋性均显著升高(P<0.05)。结论首发抑郁症患者视觉空间认知功能受损,其正像空间旋转存在功能偏侧化优势,而镜像消失。提示视觉空间认知的脑电地形图特征可能是首发抑郁症患者的潜在生物学指标。

Objective To explore the functional laterality between left and right hemisphere on visuo-spatial cognitive function in first-episode depressive disorder patients.Methods A total of 35 depressive disorder patients（experiment group） and 36 normal healthy subjects（control group） were tested to make visuo-spatial rotation tasks by the event-related potential system,and the change of the brain distribution topographic map was observed.Results ①Compared with control group,the mean error rate [（22.3±6.5）% vs（18.4±5.6）%] and the mean response time [（761.4±94.2）ms vs（634.7±84.9）ms] significantly increased in depressive disorder group（P0.05）.②Compared with control group,the normal P500 volatility at P4 was significantly decreased in depressive disorder group [（7.63±2.63）μV vs（9.58±3.22）μV,P0.05],and the mirror P500 volatility at P4 was significantly increased[（6.90±1.92）μV vs（4.95±1.92）μV,P0.05].In P500,the self mirror-normal difference of excitability disappeared in depressive disorder group.The normal excitability in the right parietal-occipital lobe was significantly higher than that in the left parietal-occipital lobe（P0.05）,but the mirror excitement difference disappeared in depressive disorder group（P0.05）.The normal and mirror excitement in the right parietal-occipital lobe were both significantly higher than those in the left in control group（P0.05）.Conclusion The visuo-spatial cognitive function is impaired in patients with first-episode depression for both normal oriented images and mirror images.The functional laterality is found in normal images for visuo-spatial rotation,but not in mirror images.Specific topographic characteristics of EEG during visuo-spatial rotation tasks are potential biomarkers for first-episode depressive disorder.