Department of Psychology, University of Zurich, Zurich, Switzerland.
Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin Ireland.
Cortex. 2022 Jun;151:272-280. doi: 10.1016/j.cortex.2022.03.011. Epub 2022 Apr 1.
"Body integrity dysphoria" (BID) is a severe condition affecting nonpsychotic individuals. In the amputation variant of BID, a limb may be experienced as not being part of the body, despite normal anatomical development and intact sensorimotor functions. We previously demonstrated altered brain structural (gray matter) and functional connectivity in 16 men with BID with a long-lasting and exclusive desire for left leg amputation. Here, we aimed to identify, in the same sample, altered patterns of white matter structural connectivity. Fractional anisotropy (FA), derived from diffusion tensor imaging data, was considered as a measure of structural connectivity. Results showed reduced structural connectivity of: (i) the right superior parietal lobule (rSPL) with the right cuneus, with the superior occipital and with the posterior cingulate gyri, (ii) the pars orbitalis of the right middle frontal gyrus (rMFGOrb) with the putamen, and (iii) the left middle temporal gyrus (lMTG) with the pars triangularis of the left inferior frontal gyrus. Increased connectivity was found between the right paracentral lobule (rPLC) and the right caudate nucleus. By using a complementary method of investigation, we confirmed and extended previous results from the same sample of individuals with BID, showing structural alterations between areas tuned to the processing of the sensorimotor representations of the affected leg (rPCL), and to higher-order components of bodily representation such as the body image (rSPL) and visual processing. Alongside this network for bodily awareness, other networks such as the limbic (rMFGOrb) and the mirror (lMTG) systems showed alterations in structural connectivity. These findings consolidate current understanding of the neural correlates of the amputation variant of BID, which might in turn guide diagnostics and rehabilitative treatments.
“身体完整性障碍”（BID）是一种影响非精神病个体的严重疾病。在 BID 的截肢变体中，尽管肢体具有正常的解剖结构和完整的感觉运动功能，但个体可能会将其体验为不属于身体的一部分。我们之前研究过 16 名 BID 患者，他们对左腿截肢有长期和排他性的渴望，这些患者的大脑结构（灰质）和功能连接存在改变。在此，我们旨在同一样本中识别出白质结构连接的改变模式。从弥散张量成像数据中得出的各向异性分数（FA）被认为是结构连接的度量。结果显示，右侧上顶叶（rSPL）与右侧楔前叶、顶枕叶和后扣带回的结构连接减少，右侧额中回眶部（rMFGOrb）与壳核的结构连接减少，左侧颞中回（lMTG）与左侧额下回三角部的结构连接减少。右侧旁中央小叶（rPLC）与右侧尾状核之间的连接增加。通过使用互补的研究方法，我们在同一 BID 患者样本中证实并扩展了之前的结果，显示了与受影响肢体的感觉运动代表处理相关的区域（rPCL）与身体代表的更高阶成分（如身体形象（rSPL）和视觉处理）之间的结构改变。除了这个身体意识网络外，其他网络（如边缘系统（rMFGOrb）和镜像系统（lMTG））的结构连接也发生了改变。这些发现巩固了对 BID 截肢变体的神经相关性的现有理解，这反过来又可能指导诊断和康复治疗。
