Altered EEG lagged coherence during rest in obsessive-compulsive disorder

Area of Science:

• Neuroscience
• Psychiatry
• Brain Connectivity

Background:

• Functional magnetic resonance imaging (fMRI) studies indicate altered functional connectivity in obsessive compulsive disorder (OCD).
• Limited knowledge exists regarding region of interest (ROI)-based electroencephalogram (EEG) connectivity, specifically lagged non-linear and linear coherence, in OCD patients.

Purpose of the Study:

• To compare lagged non-linear and linear EEG coherence measures during rest and varying vigilance stages between individuals with OCD and healthy controls (HC).

Main Methods:

• Recorded 15-minute resting-state EEG in 30 unmedicated OCD patients and 30 matched HC.
• Computed intracortical lagged non-linear coherence across main EEG-frequency bands within frontal ROIs and the default mode network (DMN) using eLORETA software.

Main Results:

• Significantly decreased lagged non-linear coherence in the beta 2 frequency between frontal brain areas was observed in OCD patients compared to HC.
• This reduction was not found within the DMN.
• Analysis of EEG-vigilance stages revealed decreased frontal phase synchronisation at beta and theta frequencies during high vigilance stages only.

Conclusions:

• Results highlight altered neuronal communication within frontal brain regions during rest in individuals with OCD.
• These connectivity findings may serve as potential biomarkers for identifying physiologically homogeneous subgroups within OCD, warranting further investigation.