EEG Frequency Correlates with α₂-Receptor Density in Parkinson's Disease

Area of Science:

• Neuroscience
• Neurology

Background:

• Quantitative electroencephalography (EEG) shows altered brain wave activity (increased theta/delta, decreased alpha/beta power) in Parkinson's disease (PD) patients, predicting dementia.
• Noradrenaline is crucial for cognitive function and cortical activity; its loss may cause cognitive impairment and EEG slowing in PD.

Purpose of the Study:

• To investigate the relationship between noradrenergic α₂ adrenoceptor density and spectral EEG changes in PD patients.

Main Methods:

• Nineteen PD patients and thirteen healthy controls (HC) underwent positron emission tomography (PET) with [¹¹C]yohimbine to measure α₂ adrenoceptor density.
• EEG power in delta, theta, alpha, and beta bands was analyzed in regression models against α₂ adrenoceptor density.

Main Results:

• PD patients exhibited higher theta and delta power than HC.
• A significant inverse correlation was found between frontal cortex α₂ adrenoceptor density and theta band power in PD patients.
• In HC subjects, age and occipital background rhythm frequency correlated with α₂ adrenoceptor density in the frontal cortex and thalamus.

Conclusions:

• Findings support the hypothesis that noradrenergic neurotransmission loss contributes to cognitive decline and EEG slowing in PD.
• This suggests α₂ adrenoceptor density as a potential biomarker for cognitive changes in Parkinson's disease.