Interhemispheric Differences of Hand Motor Cortex Organization: MEG-EMG Cortico-Muscolar Coherence.

摘要

Corticomuscular coherence between cerebral cortical rhythms and the surface electromyography (EMG) has been observed both through electrocorticogram and by electroencephalographic (EEG) and magnetoencephalographic (MEG) recordings. Corticomuscular coherence is a tool for identification and characterization of cortical districts controlling a particular body district, based on amplitude and frequency selection. MEG recordings of parietal contralateral cerebral activity, and muscular activity from right and left extensor comunis digitorum (ECD) have been studied in 5 control subjects (bandpass 0.48-250 Hz, sampling rate 1000 Hz). Preliminary results indicate in dominant hemisphere, a more concentrated frequency distribution in the coherence spectrum (higher values in a sharper frequency range) and, once selected the coherence at peck value, a more concentrated spatial distribution. Methodological optimization of the coherence procedure are discussed. These indications of dominant/non-dominant hemispheric asymmetries could be further investigated to establish physiological parameters to identify eventual alterations in the cortical motor organization induced by pathological conditions.