Elevated synchrony in Parkinson disease detected with electroencephalography

Area of Science:

• Neuroscience
• Biomarkers
• Neurological Disorders

Background:

• Parkinson disease (PD) diagnosis and treatment are challenging.
• Emerging theories link PD to excessive beta band synchronization in basal ganglia-thalamocortical loops.
• Phase-amplitude coupling (PAC) is a measure of neural synchronization.

Purpose of the Study:

• To investigate if beta-gamma PAC, measured noninvasively with electroencephalography (EEG), differs in Parkinson disease (PD) patients.
• To compare PAC in PD patients off and on medication, and with healthy controls.

Main Methods:

• Resting EEG data were collected from 15 PD patients and 16 healthy controls.
• PD patients were tested both on and off dopaminergic medication.
• Beta-gamma PAC was calculated and compared across conditions and groups.

Main Results:

• Phase-amplitude coupling (PAC) was significantly elevated in PD patients off medication compared to when they were on medication (p = 0.008).
• PAC was also significantly higher in PD patients off medication compared to healthy controls (p = 0.009).

Conclusions:

• Elevated PAC is detectable via scalp EEG in Parkinson disease (PD) patients, particularly when off medication.
• EEG-based PAC shows potential as a noninvasive biomarker for the parkinsonian state.
• This biomarker could assist in PD diagnosis, treatment adjustment, and closed-loop deep brain stimulation control.