Reduced power and phase-locking values were accompanied by thalamus, putamen, and hippocampus atrophy in Parkinson?s disease with mild cognitive impairment: an event-related oscillation study

Parkinson's disease (PD) is a multifaceted neurodegenerative disorder accompanied by mild cognitive im-pairment (MCI) as a crucial nonmotor manifestation. Event-related oscillations (EROs) are suggested to re-flect cognitive status associated with subcortical structures in neurodegenerative conditions. In this study, 36 individuals with PD-MCI and 32 PD-CN were compared with 60 healthy control (HC) participants us-ing visual EROs by measures of event-related spectral perturbation and inter-trial coherence, along with subcortical gray matter volumes based on the FIRST algorithm. Cross-correlations among electrophysio-logical, neuropsychological, and structural parameters were investigated exploratively. Both PD-MCI and PD-CN patients had diminished delta and alpha phase-locking than HC, however, electrophysiological ab-normalities were more pronounced in PD-MCI over frontal, central, parietal, and temporal locations in almost all frequency bands, accompanied by bilateral thalamus, hippocampus, and right putamen atro-phy. PD-CN had lower hippocampal volumes than HC, without exhibiting any subcortical differences from PD-MCI. Lastly, EROs showed low-to-high correlations with structural and neuropsychological measures. These findings may highlight the complex interplay between electrophysiological, neuropsychological, and structural parameters in detected abnormalities of PD-CN and PD-MCI. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Parkinson's disease (PD) is a neurodegenerative disorder with cognitive impairment as a nonmotor manifestation. This study examined the differences between PD-MCI and PD-CN patients using visual event-related oscillations (EROs) and subcortical structural measures. The results showed that both PD-MCI and PD-CN patients had abnormal EROs compared to healthy controls, but the abnormalities were more pronounced in PD-MCI. Additionally, PD-MCI showed atrophy in multiple brain regions while PD-CN had reduced hippocampal volumes. These findings suggest complex interactions between electrophysiological, neuropsychological, and structural parameters in PD.