Characterizing resting-state EEG oscillatory and aperiodic activity in neurodegenerative diseases: A multicentric study

  1. Alberto Jaramillo-Jimenez
  2. Yorguin-Jose Mantilla-Ramos
  3. Diego A Tovar-Rios
  4. Francisco Lopera
  5. David Aguillón
  6. John Fredy Ochoa-Gomez
  7. Claire Paquet
  8. Sinead Gaubert
  9. Matteo Pardini
  10. Dario Arnaldi
  11. John-Paul Taylor
  12. Tormod Fladby
  13. Kolbjørn Brønnick
  14. Dag Aarsland
  15. Laura Bonanni
0 evaluations Published on
Read the full article Related papers
This article on Sciety

Abstract

Background

Abnormalities in resting-state electroencephalogram (rsEEG) posterior alpha rhythm are promising biomarkers of neurodegenerative diseases (NDDs), often assessed via spectral analysis, ignoring the signal’s non-rhythmic (aperiodic) component. Evidence assessing aperiodic and oscillatory rsEEG abnormalities across NDDs is scarce and often underpowered. Multicenter studies could tackle these limitations, but data pooling might introduce site-related rsEEG differences (batch effects). This study aims to characterize rsEEG oscillatory and aperiodic patterns across NDDs, minimizing potential batch effects.

Methods

RsEEGs (n = 639; 11 sites) were automatically preprocessed. Signals comprised healthy controls (HC = 153), Lewy Body Dementias (LBD = 95), Parkinson’s Disease (PD = 71), Alzheimer’s Disease (AD = 186), Frontotemporal Dementia (FTD = 23), Mild Cognitive Impairment (MCI) in positive Lewy Body pathology or PD (MCI-LBD = 34), and MCI in positive AD pathology (MCI-AD = 77). Power spectrum batch effects were harmonized using reComBat (age, sex, and diagnosis-adjusted). Harmonization was evaluated with functional and mass-univariate ANOVAs. Oscillatory and aperiodic parameters were extracted from the batch-harmonized power spectrum. NDDs-related differences were estimated with functional and mass-univariate tests, bootstrapped pairwise comparisons, and logistic regressions.

Results

Qualitative visualizations and statistical testing showed reduced batch effects after harmonization. Statistically significant findings included steeper aperiodic parameters and lower oscillatory center frequency in LBD compared to other NDDs. Additionally, oscillatory extended alpha power was lower in AD vs. LBD.

Conclusions

Batch effects in the rsEEG power spectrum can be mitigated with harmonization. Oscillatory alpha power reduction may better reflect AD abnormalities, whereas pronounced oscillatory frequency slowing and greater aperiodic activity characterize LBD.

Related articles

Related articles are currently not available for this article.