Statistical Analysis
Student’s t-test was used to examine the statistical significance of inter-group (PD vs HCO) differences for values of the PSD-EEG, striatal [18F]FDOPA PET/CT uptake ratios and cognitive tests parameters. When comparing PSD-EEG parameters the inter-group comparisons’ p-values were adjusted according to the Bonferroni correction to avoid the type I error derived from multiple comparisons. Pearson’s correlation coefficient (r) or Spearman’s correlation coefficient (ρ - rho) was calculated to evaluate the associations of the PSD-EEG parameters revealing statistically significant inter-group differences with the striatal [18F]FDOPA PET/CT uptake ratios and neuropsychological parameters. Additionally, to assess the diagnostic accuracy (sensitivity and specificity) of the PSD-EEG and striatal [18F]FDOPA PET/CT uptake ratio parameters, the ROC curves were estimated and the area under the curve (AUC) values were calculated. All statistical analyses were performed with Statistica version 13.1 software, and the significance level was set at α = 0.05.