German Center for Vertigo and Balance Disorders, University Hospital, Ludwig-Maximilians-University Munich, Germany; Graduate School of Systemic Neurosciences, Munich, Germany.
Graduate School of Systemic Neurosciences, Munich, Germany; Institute for Stroke and Dementia Research, University Hospital, Ludwig-Maximilians-University Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
Neuroimage. 2020 Dec;223:117362. doi: 10.1016/j.neuroimage.2020.117362. Epub 2020 Sep 9.
Little is known about the cortical organization of human vestibular information processing. Instead of a dedicated primary vestibular cortex, a distributed network of regions across the cortex respond to vestibular input. The aim of this study is to characterize the human corticocortical vestibular network and compare it to established results in non-human primates.
We collected high-resolution multi-shell diffusion-weighted (DWI) and state-of-the-art resting-state functional MR images of 29 right-handed normal subjects. Ten cortical vestibular regions per hemisphere were predefined from previous vestibular stimulation studies and applied as regions of interest. Four different structural corticocortical vestibular networks accounting for relevant constraints were investigated. The analyses included the investigation of common network measures and hemispheric differences for functional and structural connectivity patterns alike. In addition, the results of the structural vestibular network were compared to findings previously reported in non-human primates with respect to tracer injections (Guldin and Grusser, 1998).
All structural networks independent of the applied constraints showed a recurring subdivision into identical three submodules. The structural human network was characterized by a predominantly intrahemispheric connectivity, whereas the functional pattern highlighted a strong connectivity for all homotopic nodes. A significant laterality preference towards the right hemisphere can be observed throughout the analyses: (1) with larger nodes, (2) stronger connectivity values structurally and functionally, and (3) a higher functional relevance. Similar connectivity patterns to non-human primate data were found in sensory and higher association cortices rather than premotor and motor areas.
Our analysis delineated a remarkably stable organization of cortical vestibular connectivity. Differences found between primate species may be attributed to phylogeny as well as methodological differences. With our work we solidified evidence for lateralization within the corticocortical vestibular network. Our results might explain why cortical lesions in humans do not lead to persistent vestibular symptoms. Redundant structural routing throughout the network and a high-degree functional connectivity may buffer the network and reestablish network integrity quickly in case of injury.
人类前庭信息处理的皮质组织知之甚少。没有专门的初级前庭皮质，而是皮质中的分布区域网络对前庭输入做出反应。本研究的目的是描述人类皮质-皮质前庭网络，并将其与非人类灵长类动物的已有结果进行比较。
我们收集了 29 名右利手正常受试者的高分辨率多壳弥散加权（DWI）和最先进的静息态功能磁共振图像。从前庭刺激研究中预先定义了每侧半球的 10 个皮质前庭区域，并将其作为感兴趣区域。研究了四个不同的结构皮质-皮质前庭网络，以考虑相关约束。分析包括对功能和结构连接模式的常见网络度量和半球差异的研究。此外，还比较了结构前庭网络的结果与非人类灵长类动物的示踪剂注射结果（Guldin 和 Grusser，1998）。
所有不依赖于应用约束的结构网络都表现出相同的三分结构。结构人类网络的特点是主要是半球内连接，而功能模式突出了所有同型节点的强连接。可以观察到整个分析过程中存在明显的右侧偏好：（1）节点更大，（2）结构和功能连接值更强，以及（3）功能相关性更高。在感觉和高级联合皮质中发现了与非人类灵长类动物数据相似的连接模式，而不是在运动前和运动皮质中。
我们的分析描绘了皮质前庭连接的显著稳定组织。在灵长类动物物种之间发现的差异可能归因于系统发育以及方法学差异。通过我们的工作，我们为皮质-皮质前庭网络中的偏侧化提供了确凿的证据。我们的结果可能解释了为什么人类皮质损伤不会导致持续的前庭症状。网络中的冗余结构路由和高度功能连接可能缓冲网络，并在损伤时迅速恢复网络完整性。
