P08-F Decrease of parieto-occipital beta phase locking in patients with Parkinson’s disease and Lewy body disease

Abstract

Background Event-related beta responses are related to the visual cognitive process. Beta phase-locking had decreased in subjects with cognitive deficits. Parkinson’s disease dementia (PDD) and dementia with Lewy bodies (DLB) have similar pathophysiology and have different clinical symptoEEG event-related responses in neurodegenerative diseases are remarkable for understanding the mechanisms underlying the pathophysiology. The aim of our study was to investigate the event-related beta responses in PDD and DLB patients. Material and methods 12 DLB, 14 PDD patients and matched 15 healthy controls were included in the study. There was no significant difference for the Mini-Mental State Examination score between the patient groups. EEG recordings were performed from 32 different locations during visual oddball paradigm. Phase-locking analysis was performed for beta (15–25 Hz) frequency band for all subject groups. Repeated measures of ANOVA was used for statistical analysis (p Results Healthy controls had increased beta phase locking with increasing cognitive loading. Healthy controls had higher beta phase locking than both PDD and DLB patients. LocationXGroup effect was significant for beta phase locking (p = 0.002). DLB patients had the worst beta phase locking particularly in parietal and occipital locations in comparison to other groups. Conclusions The present study showed that dementia characterized by a cognitive decline is reflected with decreased beta phase locking in posterior areas in both Parkinson’s disease and Lewy body disease. The decreased event-related beta phase locking could be a candidate of biomarkers for dementia in PDD and DLB patients.