A coherence study on EEG and EMG signals

TL;DR

This study explores the relationship between EEG and EMG signals in a focal hand dystonia patient, identifying high beta band activity as a potential biomarker for pathological bursts, which could inform new rehabilitation strategies.

Contribution

It combines frequency and time domain analyses to identify EEG-EMG interactions and suggests a specific EEG correlate for dystonia-related bursts.

Findings

High beta band activity (around 30 Hz) linked to pathological EMG bursts.

Preliminary evidence of EEG-EMG coherence in dystonia.

Potential for targeted neurorehabilitation based on EEG biomarkers.

Abstract

The aim of this study is to investigate bursts- related EEG signals in a focal hand dystonia patient. Despite of considering time domain and frequency domain techniques as mutually exclusive analysis, in this contribution we have taken advantage from both of them: particularly, in the frequency domain, coherence was used to identify the most likely frequency bands of interaction between brain and muscles, then, in the time domain, cross-correlation was exploited to verify the physiological reliability of such a relationship in terms of signal transmission delay from the centre to the periphery. Our preliminary results suggest - in line with recent literature - that activity in the high beta band (around 30 Hz) could represent an electroencephalographic correlate for the pathological electromyographic bursts affecting the focal hand dystonia condition. Even though a future study on a larger sample is needed to statistically support these preliminary findings, this contribution allows to think of new kinds of rehabilitation from focal hand dystonia that could target the actual electroencephalographic correlate of the pathology, i.e. phenotypically expressed by bursts, with the consequence of a relevant functional improvement.