Marapin Ramesh S, de Jong Bauke M, Renken Remco J, Timmers Elze R, Tijssen Marina A J, Dalenberg Jelle R
Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
UMCG Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Eur J Neurol. 2025 Apr;32(4):e70085. doi: 10.1111/ene.70085.
Currently, the pathophysiology of myoclonus-dystonia (M-D) remains insufficiently understood. This study addresses this gap by adding innovative multivariate pattern analysis (MVPA) to traditional univariate analysis of functional magnetic resonance imaging (fMRI) data.
Data from 18 M-D patients and 18 age-matched healthy volunteers who performed a finger tapping fMRI task were analyzed. Whole-brain univariate and searchlight (MVPA) analysis with varying hemodynamic response function (HRF) delays were employed to examine brain responses associated with the visually guided motor task.
Distinguishing response patterns between M-D patients and healthy volunteers revealed significant response reductions in the putamen, insula, and visual cortex. Compared to univariate analysis, searchlight analysis was more sensitive for brain activity patterns associated with finger tapping in both M-D patients and healthy volunteers. At short HRF delays, increased (pre)motor cortical responses were evident in M-D patients, whereas such responses emerged at a later HRF delay in healthy volunteers.
The task-related effects observed in M-D patients support the involvement of the basal ganglia-thalamo-cortical network. Notably, cerebellar involvement was not strongly implicated in our study. We postulate that inherent deficits in the putamen trigger either premature or downstream compensatory (motor) cortical effects. The potential involvement of the visual cortex in the M-D pathophysiology is new, but its role has been suggested by a previous study investigating visual sensory processing in SGCE gene-positive M-D patients. Our findings, including the innovative searchlight method, pave the way for further studies investigating the complex interplay between brain regions and networks and their role in M-D pathogenesis.
目前，肌阵挛性肌张力障碍（M-D）的病理生理学仍未得到充分理解。本研究通过在传统的功能磁共振成像（fMRI）数据单变量分析中加入创新的多变量模式分析（MVPA）来填补这一空白。
分析了18例M-D患者和18例年龄匹配的健康志愿者在进行手指敲击fMRI任务时的数据。采用全脑单变量和探照灯（MVPA）分析以及不同的血流动力学响应函数（HRF）延迟来检查与视觉引导运动任务相关的脑反应。
区分M-D患者和健康志愿者的反应模式显示，壳核、岛叶和视觉皮层的反应显著降低。与单变量分析相比，探照灯分析对M-D患者和健康志愿者中与手指敲击相关的脑活动模式更敏感。在较短的HRF延迟时，M-D患者的（运动前）皮质反应增加，而在健康志愿者中，这种反应在较晚的HRF延迟时出现。
在M-D患者中观察到的任务相关效应支持基底神经节-丘脑-皮质网络的参与。值得注意的是，在我们的研究中，小脑的参与并不明显。我们推测，壳核的内在缺陷会触发过早或下游的代偿性（运动）皮质效应。视觉皮层在M-D病理生理学中的潜在参与是新的，但之前一项研究调查SGCE基因阳性M-D患者的视觉感觉处理时已经提出了其作用。我们的发现，包括创新的探照灯方法，为进一步研究脑区和网络之间的复杂相互作用及其在M-D发病机制中的作用铺平了道路。
