Spectral features of resting-state EEG in Parkinson's Disease: A multicenter study using functional data analysis
Alberto Jaramillo-Jiménez, Diego Tovar, Johann Alexis Ospina Galindez, Yorguin-Jose Mantilla-Ramos, Daniel Loaiza-López, Verónica Henao Isaza, Luisa María Zapata Saldarriaga, Valeria Cadavid Castro, Jazmín Ximena Suárez-Revelo, Yamile Bocanegra, Francisco Lopera, David Antonio Pineda-Salazar, Carlos Tobón, John Fredy Ochoa-Gómez, Miguel Germán Borda, Dag Aarsland, Laura Bonanni, Kolbjørn Brønnick
Abstract
OBJECTIVE: This study aims 1) To analyse differences in resting-state electroencephalogram (rs-EEG) spectral features of Parkinson's Disease (PD) and healthy subjects (non-PD) using Functional Data Analysis (FDA) and 2) To explore, in four independent cohorts, the external validity and reproducibility of the findings using both epoch-to-epoch FDA and averaged-epochs approach. METHODS: We included 169 subjects (85 non-PD; 84 PD) from four centres. Rs-EEG signals were preprocessed with a combination of automated pipelines. Sensor-level relative power spectral density (PSD), dominant frequency (DF), and DF variability (DFV) features were extracted. Differences in each feature were compared between PD and non-PD on averaged epochs and using FDA to model the epoch-to-epoch change of each feature. RESULTS: For averaged epochs, significantly higher theta relative PSD in PD was found across all datasets. Also, higher pre-alpha relative PSD was observed in three of four datasets in PD patients. For FDA, similar findings were achieved in theta, but all datasets showed consistently significant posterior pre-alpha differences across multiple epochs. CONCLUSIONS: Increased generalised theta, with posterior pre-alpha relative PSD, was the most reproducible finding in PD. SIGNIFICANCE: Rs-EEG theta and pre-alpha findings are generalisable in PD. FDA constitutes a reliable and powerful tool to analyse epoch-to-epoch the rs-EEG.