Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy.
Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy
Mult Scler. 2015 Jul;21(8):1003-12. doi: 10.1177/1352458514558474. Epub 2014 Dec 22.
Major depression (MD) is a common psychiatric disorder in multiple sclerosis (MS). Despite the negative impact of MD on the quality of life of MS patients, little is known about its underlying brain mechanisms.
We studied the whole-brain connectivity patterns that were associated with MD in MS. Alterations were mainly expected within limbic circuits.
Diffusion tensor imaging data were collected in 20 MS patients with MD, 22 non-depressed MS patients and 16 healthy controls. We used deterministic tractography and graph analysis to study the white-matter connectivity patterns that characterized MS patients with MD.
We found that MD in MS was associated with increased local path length in the right hippocampus and right amygdala. Further analyses revealed that these effects were driven by an increased shortest distance between both the right hippocampus and right amygdala and a series of regions including the dorsolateral and ventrolateral prefrontal cortex, orbitofrontal cortex, sensory-motor cortices and supplementary motor area.
Our data provide strong support for neurobiological accounts positing that MD in MS is mediated by abnormal 'communications' within limbic circuits. We also found evidence that MD in MS may be linked with connectivity alterations at the limbic-motor interface, a group of regions that translates emotions into survival-oriented behaviors.
重度抑郁症（MD）是多发性硬化症（MS）中常见的精神障碍。尽管 MD 对 MS 患者的生活质量有负面影响，但对其潜在的大脑机制知之甚少。
我们研究了与 MS 中的 MD 相关的全脑连接模式。预计主要会发生在边缘回路中。
在 20 名患有 MD 的 MS 患者、22 名非抑郁 MS 患者和 16 名健康对照者中收集了弥散张量成像数据。我们使用确定性束追踪和图分析来研究以 MS 患者 MD 为特征的白质连接模式。
我们发现，MS 中的 MD 与右侧海马体和右侧杏仁核的局部路径长度增加有关。进一步的分析表明，这些影响是由右侧海马体和右侧杏仁核之间最短距离的增加以及包括背外侧和腹外侧前额叶皮层、眶额皮层、感觉运动皮层和辅助运动区在内的一系列区域驱动的。
我们的数据为神经生物学假说提供了强有力的支持，即 MS 中的 MD 是由边缘回路内的异常“通讯”介导的。我们还发现，MS 中的 MD 可能与边缘运动接口的连接改变有关，这是一组将情绪转化为生存导向行为的区域。
