Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK.
The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK.
Tremor Other Hyperkinet Mov (N Y). 2024 Aug 28;14:43. doi: 10.5334/tohm.904. eCollection 2024.
Essential tremor (ET) and dystonic tremor (DT) are movement disorders that cause debilitating symptoms, significantly impacting daily activities and quality of life. A poor understanding of their pathophysiology, as well as the mediators of clinical outcomes following deep brain stimulation (DBS), highlights the need for biomarkers to accurately characterise and optimally treat patients.
We assessed the white matter microstructure of pathways implicated in the pathophysiology and therapeutic intervention in a retrospective cohort of patients with DT (n = 17) and ET (n = 19). We aimed to identity associations between white matter microstructure, upper limb tremor severity, and tremor improvement following DBS.
A fixel-based analysis pipeline was implemented to investigate white matter microstructural metrics in the whole brain, cerebello-thalamic pathways and tracts connected to stimulation volumes following DBS. Associations with preoperative and postoperative severity were analysed within each disorder group and across combined disorder groups.
DBS led to significant improvements in both groups. No group differences in stimulation positions were identified. When white matter microstructural data was aligned according to the maximally affected upper limb, increased fiber density, and combined fiber density & cross-section of fixels in the left cerebellum were associated with greater tremor severity across DT and ET patients. White matter microstructure did not show associations with postoperative changes in cerebello-thalamic pathways, or tracts connected to stimulation volumes.
Diffusion changes of the cerebellum are associated with the severity of upper limb tremor and appear to overlap in essential or dystonic tremor disorders.
特发性震颤（ET）和肌张力障碍性震颤（DT）是两种运动障碍，会导致使人衰弱的症状，严重影响日常活动和生活质量。对其病理生理学以及深部脑刺激（DBS）后临床结果的介导因素了解不足，突出了需要生物标志物来准确描述和优化治疗患者。
我们评估了与 DT（n=17）和 ET（n=19）患者的病理生理学和治疗干预相关的途径的白质微观结构。我们旨在确定白质微观结构、上肢震颤严重程度和 DBS 后震颤改善之间的关联。
实施了基于固定体的分析管道，以研究整个大脑、小脑-丘脑通路以及与 DBS 后刺激体积相连的束的白质微观结构指标。在每个疾病组和跨组合疾病组内分析了与术前和术后严重程度的关联。
两组均有显著改善。未发现刺激位置的组间差异。当根据受影响最大的上肢对白质微观结构数据进行调整时，左侧小脑的固定体纤维密度增加以及纤维密度和横截面与 DT 和 ET 患者的震颤严重程度相关。白质微观结构与小脑-丘脑通路或与刺激体积相连的束的术后变化无关。
小脑的弥散变化与上肢震颤的严重程度相关，并且在特发性或肌张力障碍性震颤疾病中似乎重叠。
