伴有抑郁症状原发性失眠患者静息态磁共振脑默认网络评价

Default mode network assessment of resting state functional MRI in insomnia patients with depression symptom

目的利用静息态磁共振脑功能成像（fMRI）技术，评价伴有不同程度抑郁症状的原发性失眠（primary insomnia，PI）患者脑默认网络差异及其发生的神经网络机制。方法于2012年1月至2015年6月收集不伴抑郁症状的单纯PI患者15例，PI伴有轻、中度抑郁症状患者各20例，健康对照组（healthy control，HC）40例，以双侧后扣带回／楔前叶为种子点，对比HC与PI伴抑郁症状组间脑默认网络差异；对比PI伴有不同程度抑郁症状各组间脑默认网络差异。分别提取右侧中间扣带回和海马旁回的信号与汉密尔顿抑郁量表（HAMD）评分结果进行相关性分析。结果与HC组对比，PI伴有抑郁组功能连接增强脑区包括：双侧楔前叶、左枕中回、顶上小叶、额上回；功能连接减弱脑Ⅸ包括：左侧前扣带回。与单纯PI组相比，PI伴有轻度抑郁症状组功能连接减弱脑区包括：双侧额中回、右侧枕中回／楔前叶、中央后回，无功能连接增强脑区；与伴轻度抑郁症状PI组相比，PI伴有中度抑郁组功能连接增强脑区包括：右侧小脑后叶、中间扣带回、左侧岛叶／额下回、外核、顶下小叶，功能连接减弱脑区包括：左侧颞上回、右侧海马旁回。右侧海马旁回、右侧中间扣带回信号与HAMD评分相关性分析结果分别为：r=-0．697，P=0．006；r=0．224，P=0．441。结论PI伴有抑郁症状患者存在脑默认网络异常；伴有不同程度抑郁症状PI患者之间存在脑默认网络差异；海马旁回功能连接与HAMD评分显著负相关，中间扣带回功能连接与HAMD评分相关性不显著，但趋势一致。

Objective To assess abnormal default mode network （DMN） and its potential mechanisms in insomnia patients with varying depression symptom via resting state functional magnetic resonance imaging （fMRI）. Methods We recruited 15 cases of primary insomnia （PI） without depression symptom, 40 cases of insomnia patients with varying depressions, including mild depression （ n = 20 ） and moderate depression （ n = 20） , and 40 cases of healthy controls （HC） with age and gender matched . We set bilateral posterior cingulate cortex and precuneus （PCC/PC） as seed regions, and compared the DMN changes between HC group and PI with depression symptoms group. We then compared the DMN changes between PI with mild and moderate depression groups. Finally, we extracted right cingulate cortex and parahippocampal signals and made Pearson correlation coefficient analysis with the Hamilton Depression Scale （HAMD） scores. Results The connectivity of PI with depression symptoms group was increased in brain regions including bilateral preeuneus, left middle occipital gyrus, superior parietal lobe, superior frontal lobe, and was decreased in brain regions including left anterior cingulate cortex, compared with HC group. Compared with PI without depression symptoms group, the connectivity of PI with mild depression symptoms group was decreased in brain regions including bilateral middle frontal gyms, right middle occipital gyrus/precuneus, and was not increased in brain regions in insomnia with mild group. Compared with PI with mild depression symptoms group, the connectivity of PI with moderate depression symptoms group was increased in brain regions including right cerebellum posterior lobe, middle cingulate cortex, left insular lobe/inferior frontal lobe, extra nuclear and inferior parietal lobe, and was decreased in brain regions in insomnia with moderate depression symptoms group including left superior temporal lobe and right parahippocampal gyms. Pearson correlation coefficient analysis showed significant correlation between signals of right parahippocampal gyrus and HAMD scores （ r = - 0. 697, P = 0. 006 ）, while not between signals of right middle cingnlate cortex and HAMD scores （r = 0. 224, P = 0. 441 ）. Conclusions There were abnormal DMN in PI with depression symptoms group, and in PI with varying degrees of depression symptoms groups. Our results revealed specified brain regions of cognitive dysfunction and neural pathological mechanisms which were affected by PI with depression symptom.