Comparison of Quantitative-Electroencephalogram (q-EEG) Measurements Between Patients of Dementia with Lewy Bodies (DLB) and Parkinson Disease Dementia (PDD).

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) are synucleinopathy syndromes with similar symptom profiles that are distinguished clinically based on the arbitrary rule of the time of symptom onset. Identifying reliable electroencephalographic (EEG) biomarkers would provide a precise method for better diagnosis, treatment, and monitoring of treatment response in these two types of dementia. From April 2015 to March 2021, the records of new referrals to a neurology clinic were retrospectively reviewed and 28 DLB(70.3% male) and 20 PDD (80.8% male) patients with appropriate EEG were selected for this study. Artifact-free 60-s EEG signals (21 channels) at rest with eyes closed were analyzed using EEGLAB, and regional spectral power ratios were extracted. Marked diffuse slowing was found in DLB patients compared to PDD patients in all regions in terms of decrease in alpha and increase in theta band. Although, these findings demean between groups after adjusting for MMSE scores, the significant difference still remained in terms of the mean relative alpha powers, particularly in the anterior and central regions. QEEG measures may have the potential to discriminate between these two syndromes. However, further prospective and longitudinal studies are required to improve the early differentiation of these dementia syndromes and to elucidate the underlying causes and pathogenesis and specific treatment.