Resting-state functional connectivity of dentate nucleus is associated with tremor in Parkinson's disease

Cerebello-thalamo-cortical circuit has been indicated important for tremor in Parkinson's disease (PD), but the role of dentate nucleus (DN) in parkinsonian tremor remains unclear. To investigate whether DN plays a role in PD tremor, we recruited 50 PD and 29 age-matched health controls (HC). The patients were divided into tremor-dominant (TD) and non-tremor-dominant (NTD) groups. We collected resting-state fMRIs data for each subject. The bilateral DN was then chosen as the region of interest to examine PD tremor-related network changes, as well as its correlation with tremor severity. Voxel-wise functional connectivity analysis revealed that the bilateral DN had higher connectivity with the bilateral cerebellar anterior lobe, and had lower connectivity with the bilateral prefrontal cortex in TD compared to the HC and NTD groups. Functional connectivity of the bilateral DN with the bilateral cerebellar posterior lobe was also higher in TD than NTD group. Functional connectivity between the bilateral DN and the bilateral cerebellar posterior lobe showed positive correlation with tremor severity, while that between the bilateral DN and the bilateral prefrontal cortex displayed negative correlation. Our study demonstrates higher dentato-cerebellar connectivity and lower dentato-prefrontal connectivity in TD patients, which might be involved in the pathogenesis of PD tremor. And we conclude that DN might be associated with the pathogenesis of PD tremor.