Department of Psychiatry, Western University, University Hospital, (Room C3-103), 339 Windermere Road, London, ON, N6A 5A5, Canada.
Imaging, Lawson Health Research Institute, London, ON, Canada.
Cerebellum. 2023 Dec;22(6):1083-1097. doi: 10.1007/s12311-022-01467-4. Epub 2022 Sep 19.
The flocculus is a region of the vestibulocerebellum dedicated to the coordination of neck, head, and eye movements for optimal posture, balance, and orienting responses. Despite growing evidence of vestibular and oculomotor impairments in the aftermath of traumatic stress, little is known about the effects of chronic psychological trauma on vestibulocerebellar functioning. Here, we investigated alterations in functional connectivity of the flocculus at rest among individuals with post-traumatic stress disorder (PTSD) and its dissociative subtype (PTSD + DS) as compared to healthy controls. Forty-four healthy controls, 57 PTSD, and 32 PTSD + DS underwent 6-min resting-state MRI scans. Seed-based functional connectivity analyses using the right and left flocculi as seeds were performed. These analyses revealed that, as compared to controls, PTSD and PTSD + DS showed decreased resting-state functional connectivity of the left flocculus with cortical regions involved in bodily self-consciousness, including the temporo-parietal junction, the supramarginal and angular gyri, and the superior parietal lobule. Moreover, as compared to controls, the PTSD + DS group showed decreased functional connectivity of the left flocculus with the medial prefrontal cortex, the precuneus, and the mid/posterior cingulum, key regions of the default mode network. Critically, when comparing PTSD + DS to PTSD, we observed increased functional connectivity of the right flocculus with the right anterior hippocampus, a region affected frequently by early life trauma. Taken together, our findings point toward the crucial role of the flocculus in the neurocircuitry underlying a coherent and embodied self, which can be compromised in PTSD and PTSD + DS.
小脑绒球是前庭小脑的一个区域,专门用于协调颈部、头部和眼部运动,以保持最佳姿势、平衡和定向反应。尽管有越来越多的证据表明创伤后应激会导致前庭和眼球运动受损,但人们对慢性心理创伤对前庭小脑功能的影响知之甚少。在这里,我们研究了创伤后应激障碍(PTSD)及其分离型(PTSD+DS)个体与健康对照组相比,静息状态下小脑绒球的功能连接变化。44 名健康对照者、57 名 PTSD 患者和 32 名 PTSD+DS 患者接受了 6 分钟的静息态 MRI 扫描。使用右侧和左侧绒球作为种子进行基于种子的功能连接分析。这些分析表明,与对照组相比,PTSD 和 PTSD+DS 表现出左绒球与躯体自我意识相关皮质区域的静息状态功能连接减少,包括颞顶联合区、缘上回和角回以及顶下小叶。此外,与对照组相比,PTSD+DS 组左绒球与内侧前额叶皮质、楔前叶和中/后扣带回的功能连接减少,这些区域是默认模式网络的关键区域。至关重要的是,当将 PTSD+DS 与 PTSD 进行比较时,我们观察到右绒球与右侧前海马体的功能连接增加,而前海马体是受早期生活创伤影响的频繁区域。总之,我们的研究结果表明绒球在支持连贯和体现自我的神经回路中起着至关重要的作用,而创伤后应激障碍和 PTSD+DS 可能会损害这种作用。