Chen Ziqi, Zhang Huawei, Jia Zhiyun, Zhong Jingjie, Huang Xiaoqi, Du Mingying, Chen Lizhou, Kuang Weihong, Sweeney John A, Gong Qiyong
Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, PR China.
1] Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, PR China [2] Department of Nuclear Medicine, West China Hospital of Sichuan University, Chengdu, PR China.
Sci Rep. 2015 Apr 8;5:9670. doi: 10.1038/srep09670.
Magnetization transfer imaging (MTI) provides a quantitative measure of the macromolecular structural integrity of brain tissue, as represented by magnetization transfer ratio (MTR). In this study, we utilized MTI to identify biophysical alterations in MDD patients with a history of suicide attempts relative to MDD patients without such history. The participants were 36 medication-free MDD patients, with (N = 17) and without (N = 19) a history of a suicide attempt, and 28 healthy controls matched for age and gender. Whole brain voxel-based analysis was used to compare MTR across three groups and to analyze correlations with symptom severity and illness duration. We identified decreased MTR in left inferior parietal lobule and right superior parietal lobule in suicide attempters relative to both non-attempters and controls. Non-attempters also showed significantly reduced MTR in left inferior parietal lobule relative to controls, as well as an MTR reduction in left cerebellum. These abnormalities were not correlated with symptom severity or illness duration. Depressed patients with a history of suicide attempt showed bilateral abnormalities in parietal cortex compared to nonsuicidal depressed patients and healthy controls. Parietal lobe abnormalities might cause attentional dysfunction and impaired decision making to increase risk for suicidal behavior in MDD.
磁化传递成像（MTI）提供了一种对脑组织大分子结构完整性的定量测量方法，以磁化传递率（MTR）来表示。在本研究中，我们利用MTI来识别有自杀未遂史的重度抑郁症（MDD）患者相对于无此类病史的MDD患者的生物物理改变。参与者为36名未服用药物的MDD患者，其中有自杀未遂史的（N = 17）和无自杀未遂史的（N = 19），以及28名年龄和性别匹配的健康对照者。基于全脑体素的分析用于比较三组之间的MTR，并分析其与症状严重程度和病程的相关性。我们发现，相对于未自杀未遂者和健康对照者，自杀未遂者左侧顶下小叶和右侧顶上小叶的MTR降低。未自杀未遂者相对于健康对照者，左侧顶下小叶的MTR也显著降低，并且左侧小脑的MTR也有所降低。这些异常与症状严重程度或病程无关。与无自杀行为的抑郁症患者和健康对照者相比，有自杀未遂史的抑郁症患者在顶叶皮层出现双侧异常。顶叶异常可能导致注意力功能障碍和决策受损，从而增加MDD患者自杀行为的风险。
