Resting-State Functional Magnetic Resonance Imaging Study Comparing Tremor-Dominant Parkinson's Disease and Essential Tremor.

RATIONALE AND OBJECTIVES: Tremor-dominant Parkinson's disease (TDPD) and essential tremor (ET) are the two most prevalent disorders associated with tremors. In the advanced stages of these diseases, the development of overlapping symptoms complicates differentiation between these two conditions when relying solely on clinical manifestations. Our primary aim was to explore differences in intra- and interbrain network functional connectivity (FC) and patterns of spontaneous neuronal activity in patients with ET and TDPD. MATERIALS AND METHODS: This study included 33 patients with TDPD, 42 patients with ET, and 52 sex- and age-matched healthy controls. Independent component analysis was used to analyze inter- and intranetwork FC differences of patients with ET and TDPD. The amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) techniques were used to explore patterns of spontaneous neural activity, and correlations between these changes and tremor-related scales were analyzed. RESULTS: Compared to the ET group, internetwork FC analysis revealed reduced connectivity in the ventral default mode network (vDMN)-anterior salience network, and increased connectivity in the dorsal DMN-precuneus network and sensorimotor network-visuospatial network in the TDPD group. Intranetwork FC analysis revealed significant differences in the vDMN in the three groups. Differences were observed in ALFF values of cingulum_Mid_R and ReHo values of precuneus_R in the three groups. CONCLUSION: The inter- and intranetwork FC and spontaneous brain activity patterns of ET and TDPD are different, suggesting that it helps to better understand brain network connectivity changes in ET and TDPD, while providing potential neuroimaging clues for the differential diagnosis of the two conditions.