Department of Human Sciences, Guglielmo Marconi University, Rome, Italy.
First Department of Neurosurgery, Medical School, National and Kapodistrian, University of Athens, Athens, Greece.
Laterality. 2021 Sep;26(5):564-583. doi: 10.1080/1357650X.2020.1866000. Epub 2020 Dec 29.
Xenomelia is a rare condition characterized by a persistent and intense desire for amputation of one or more healthy limbs. Some frequent clinical manifestations suggest the involvement of distinct neural substrates. Specifically, recent aetiopathological hypotheses about xenomelia propose a neurodevelopmental origin, highlighting the putative contribution of the right parietal lobe and right insula, known to subserve the construction of a coherent representation of the body as a whole. This literature review is aimed at analysing relevant findings about structural and functional brain correlates of xenomelia, focusing on the identification of key regions and their hemispheric distribution. Finally, implications about the potential link between xenomelia and phylogenetic development of the right parietal lobe are discussed. Despite a certain degree of heterogeneity and the spatial extension of networks involved, signs of partial right-sided lateralization of nodes and left-sided lateralization of nodes emerged. Indeed, some areas-rsPL, riPL, PMC and rInsula-have been consistently found altered in xenomelia. In conclusion, the presence of both structural and functional multi-layered brain abnormalities in xenomelia suggests a multifactorial aetiology; however, as the prevalence of correlational studies, causal relationships remain to be investigated.
异肢现象是一种罕见的病症，其特征是持续且强烈地渴望截除一个或多个健康的肢体。一些常见的临床表现表明涉及到不同的神经基础。具体来说，最近关于异肢现象的病因病理假说提出了神经发育起源，强调了右顶叶和右岛叶的潜在作用，已知它们参与构建整体身体的连贯表示。本文献综述旨在分析异肢现象的结构和功能脑相关物的相关发现，重点关注关键区域及其半球分布的识别。最后，讨论了异肢现象与右顶叶的系统发育发展之间的潜在联系。尽管存在一定程度的异质性和涉及的网络的空间扩展，但节点的右侧偏侧化和节点的左侧偏侧化的迹象出现了。事实上，在异肢现象中已经一致发现一些区域 - rsPL、riPL、PMC 和 rInsula - 发生了改变。总之，异肢现象存在结构和功能的多层次脑异常，表明其具有多因素病因；然而，由于相关研究的普遍性，因果关系仍有待研究。
