Tremor dominant Parkinson’s disease (TDPD) and essential tremor plus (ETP) syndrome are commonly encountered tremor dominant neurological disorders. Although the basal ganglia thalamocortical (BGTC) and cerebello thalamocortical (CTC) networks are implicated in tremorogenesis, the extent of functional connectivity alterations across disorders is uncertain. This study aims to evaluate functional connectivity of the BGTC and CTC in TDPD and ETP. Resting state functional MRI was acquired for 25 patients with TDPD, ETP and 22 healthy controls (HC). Following pre-processing and denoising, seed-to-voxel based connectivity was carried out at FDR < 0.05 using ROIs belonging to the BGTC and CTC. Fahn-Tolosa-Marin tremor rating scale (FTMRS) was correlated with the average connectivity values at FDR < 0.05. Compared to HC, TDPD showed decreased connectivity between cerebellum and pre, post central gyrus. While, ETP showed decreased connectivity between pallidum and occipital cortex, precuneus, cuneus compared to HC. In comparison to ETP, TDPD showed increased connectivity between precentral gyrus, pallidum, SNc with the default mode network (DMN), and decreased connectivity between cerebellum with superior, middle frontal gyrus was observed. Tremor severity positively correlated with connectivity between SNc and DMN in TDPD, and negatively correlated with pallidal connectivity in ETP. Pattern of BGTC, CTC involvement is differential i.e., higher connectivity of the BGTC nodes in TDPD, and higher connectivity of cerebellar nodes in ETP. The interesting observation of pallidal involvement in ETP suggests the role of BGTC in the pathogenesis of ETP, and indicated similarities in concepts of tremor genesis in TDPD and ETP.

震颤主导型帕金森病（TDPD）和特发性震颤综合征（ETP）是常见的震颤主导型神经系统疾病。尽管基底节丘脑皮质（BGTC）和小脑丘脑皮质（CTC）网络与震颤发生有关，但不同疾病之间功能连接改变的程度尚不确定。本研究旨在评估 TDPD 和 ETP 中 BGTC 和 CTC 的功能连接。对 25 名 TDPD、ETP 患者和 22 名健康对照 (HC) 进行了静息态功能 MRI 采集。预处理和去噪后，使用属于 BGTC 和 CTC 的 ROI 在 FDR < 0.05 下进行基于种子到体素的连接。Fahn-Tolosa-Marin 震颤评定量表 (FTMRS) 与 FDR < 0.05 时的平均连接值相关。与 HC 相比，TDPD 显示小脑与中央前、后回之间的连接性降低。同时，与HC相比，ETP显示苍白球和枕叶皮质、楔前叶、楔骨之间的连接性降低。与 ETP 相比，TDPD 显示中央前回、苍白球、SNc 与默认模式网络 (DMN) 之间的连接性增加，并且观察到小脑与额中回上回之间的连接性减少。TDPD 中震颤严重程度与 SNc 和 DMN 之间的连接呈正相关，与 ETP 中苍白球连接呈负相关。BGTC、CTC 参与的模式是不同的，即，TDPD 中 BGTC 节点的连通性较高，ETP 中小脑节点的连通性较高。ETP 中苍白球参与的有趣观察表明 BGTC 在 ETP 发病机制中的作用，并表明 TDPD 和 ETP 震颤发生概念的相似性。