Correlation of Visuospatial Ability and EEG Slowing in Patients with Parkinson’s Disease

Abstract

Background. Visuospatial dysfunction is among the first cognitive symptoms in Parkinson's disease (PD) and is often predictive for PD-dementia. Furthermore, cognitive status in PD-patients correlates with quantitative EEG. This cross-sectional study aimed to investigate the correlation between EEG slowing and visuospatial ability in nondemented PD-patients. Methods. Fifty-seven nondemented PD-patients (17 females/40 males) were evaluated with a comprehensive neuropsychological test battery and a high-resolution 256-channel EEG was recorded. A median split was performed for each cognitive test dividing the patients sample into either a normal or lower performance group. The electrodes were split into five areas: frontal, central, temporal, parietal, and occipital. A linear mixed effects model (LME) was used for correlational analyses and to control for confounding factors. Results. Subsequently, for the lower performance, LME analysis showed a significant positive correlation between ROCF score and parietal alpha/theta ratio (b = .59, p = .012) and occipital alpha/theta ratio (b = 0.50, p = .030). No correlations were found in the group of patients with normal visuospatial abilities. Conclusion. We conclude that a reduction of the parietal alpha/theta ratio is related to visuospatial impairments in PD-patients. These findings indicate that visuospatial impairment in PD-patients could be influenced by parietal dysfunction.

EEG changes and motor deficits in Parkinson’s disease patients: Correlation of motor scales and EEG power bands

“…This is the first study that assessed the correlation of these EEG alterations with an increased number of FOG episodes. The observed effect can be explained by the presence of general EEG slowing (an increase of power in lower frequency bands and increase of power in higher frequency bands) in PDs as the disease progresses [26][27][28][29][30]35], affecting one's ability to initiate and coordinate motor movements. We have also found a similar trend between high and low-frequency bands and the motor part of the UPDRS scale.…”

The Increase of Theta Power and Decrease of Alpha/Theta Ratio as a Manifestation of Cognitive Impairment in Parkinson’s Disease

“…The absolute and relative power in each electrode and for the average PSD was calculated in different frequency bands: delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), low alpha (8–10 Hz), high alpha (10–13 Hz), beta (13–30 Hz) and gamma (30–45 Hz). We also computed two different power ratios: alpha/theta ratio [ 36 ] and Spectral Power Ratio (SPR) (alpha + beta)/(delta + theta) [ 37 ]. To perform the connectivity analysis, we used the Phase Lag Index (PLI) measure.…”

Early detection of Parkinson's disease: Systematic analysis of the influence of the eyes on quantitative biomarkers in resting state electroencephalography

“…We found consistent trends for different EEG oscillations in PD with previous studies in both EC [ 21 , [25] , [26] , [27] , [28] , [29] , [30] , [31] ] and EO [ 44 , 63 ], with no significant differences between the groups for relative α-power. Regardless of the consistent trends, the statistical analyses reported in the literature are somewhat controversial [ 15 , 25 , 64 ] as well as the relationship between clinical symptoms and EEG biomarkers [ 23 , 51 , 65 , 66 ]. We believe that these controversial results are due to the disease's progressive nature, with the additional confusion of a different disease etiology.…”