Center for Imaging of Neurodegenerative Diseases, VAMC, San Francisco, CA, USA; Dept of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
VA Epilepsy Center of Excellence, VAMC, San Francisco, CA, USA; Dept. of Neurology, University of California, San Francisco, CA, USA.
Neuroimage Clin. 2024;43:103664. doi: 10.1016/j.nicl.2024.103664. Epub 2024 Aug 29.
Increased resting state functional connectivity between regions involved in emotion control with regions with other specializations, e.g. motor control (emotional hyperconnectivity) is one of the most consistent imaging findings in persons suffering from dissociative seizures (DS). The overall goal of this study was to better characterize DS-related emotional hyperconnectivity using dynamic resting state analysis combined with brainstem volumetry to investigate 1. If emotional hyperconnectivity is restricted to a single state. 2. How volume losses within the modulatory and emotional motor subnetworks of the neuromodulatory system influence the expression of the emotional hyperconnectivity.
13 persons with dissociative seizures (PDS) (f/m:10/3, mean age (SD) 44.6 (11.5)) and 15 controls (CON) (f/m:10/5, mean age (SD) 41.7 (13.0)) underwent a mental health test battery and structural and functional imaging at 3 T. Deformation based morphometry was used to assess brain volume loss by extracting the mean Jacobian determinants from 457 brain, forebrain and brainstem structures. The bold signals from 445 brainstem and brain rois were extracted with CONN and a dynamic fMRI analysis combined with graph and hierarchical analysis was used to identify and characterize 9 different brain states. Welch's t tests and Kendall tau tests were used for group comparisons and correlation analyses.
The duration of Brain state 6 was longer in PDS than in CON (93.1(88.3) vs. 23.4(31.2), p = 0.01) and positively correlated with higher degrees of somatization, depression, PTSD severity and dissociation. Its global connectivity was higher in PDS than CON (90.4(3.2) vs 86.5(4.2) p = 0.01) which was caused by an increased connectivity between regions involved in emotion control and regions involved in sense of agency/body control. The brainstem and brainstem-forebrain modulatory and emotional motor subnetworks of the neuromodulatory system were atrophied in PDS. Atrophy severity within the brainstem-forebrain subnetworks was correlated with state 6 dwell time (modulatory: tau = -0.295, p = 0.03; emotional motor: tau = -0.343, p = 0.015) and atrophy severity within the brainstem subnetwork with somatization severity (modulatory: tau = -0.25, p = 0.036; emotional motor: tau = -0.256, p = 0.033).
DS-related emotional hyperconnectivity was restricted to state 6 episodes. The remaining states were not different between PDS and CON. The modulatory subnetwork synchronizes brain activity across brain regions. Atrophy and dysfunction within that subnetwork could facilitate the abnormal interaction between regions involved in emotion control with those controlling sense of agency/body ownership during state 6 and contribute to the tendency for somatization in PDS. The emotional motor subnetwork controls the activity of spinal motoneurons. Atrophy and dysfunction within this subnetwork could impair that control resulting in motor symptoms during DS. Taken together, these findings indicate that DS have a neurophysiological underpinning.
在患有分离性癫痫（DS）的患者中，与其他专业区域（例如运动控制）相关的情绪控制区域之间的静息状态功能连接增加（情绪超连接）是最一致的影像学发现之一。本研究的总体目标是使用动态静息状态分析结合脑干体积测量来更好地描述与 DS 相关的情绪超连接，以调查：1. 情绪超连接是否仅限于单一状态。2. 神经调制系统的调制和情绪运动子网中的体积损失如何影响情绪超连接的表达。
13 名患有分离性癫痫的患者（PDS）（f/m：10/3，平均年龄（SD）44.6（11.5））和 15 名对照者（CON）（f/m：10/5，平均年龄（SD）41.7（13.0））在 3T 进行了心理健康测试和结构及功能成像。通过从 457 个大脑、前脑和脑干结构中提取平均雅可比行列式，使用变形基形态计量学评估大脑体积损失。使用 CONN 提取 445 个脑干和脑 ROI 的大胆信号，并使用动态 fMRI 分析结合图和分层分析来识别和描述 9 种不同的大脑状态。Welch t 检验和 Kendall tau 检验用于组间比较和相关性分析。
PDS 中脑状态 6 的持续时间长于 CON（93.1（88.3）比 23.4（31.2），p=0.01），并且与更高程度的躯体化、抑郁、创伤后应激障碍严重程度和分离有关。其全局连接性在 PDS 中高于 CON（90.4（3.2）比 86.5（4.2），p=0.01），这是由于情绪控制区域和代理感/身体控制区域之间的连接增加所致。神经调制系统的脑干和脑干-前脑调制和情绪运动子网在 PDS 中萎缩。脑干-前脑子网内的萎缩严重程度与状态 6 驻留时间相关（调制：tau=-0.295，p=0.03；情绪运动：tau=-0.343，p=0.015），脑干子网内的萎缩严重程度与躯体化严重程度相关（调制：tau=-0.25，p=0.036；情绪运动：tau=-0.256，p=0.033）。
DS 相关的情绪超连接仅限于状态 6 发作。PDS 和 CON 之间其余状态没有差异。调制子网在整个大脑区域之间同步大脑活动。该子网内的萎缩和功能障碍可能促进情绪控制区域与控制代理感/身体所有权的区域之间在状态 6 期间的异常相互作用，并导致 PDS 中的躯体化倾向。情绪运动子网控制脊髓运动神经元的活动。该子网内的萎缩和功能障碍可能会损害该控制，导致 DS 期间出现运动症状。综上所述，这些发现表明 DS 具有神经生理学基础。
