Motor function assessment, cortico-muscular coupling, wavelet coherence, transfer spectrum entropy, Medical technology, R855-855.5, Therapeutics. Pharmacology, RM1-950

Corticomuscular coupling (CMC) can quantify the information interaction between the brain and muscles during motor control. However, current research regarding changes in CMC after stroke is inconsistent. To address this, this paper propose a novel use of $\textit {CMC}_{\textit {dif}}$ as an indicator to assess motor function after stroke. This indicator include $\textit {WC}_{\textit {dif}}$ , derived from wavelet coherence analysis and $\textit {TSE}_{\textit {dif}}$ , derived from transfer spectral entropy analysis. Twelve stroke patients and twelve healthy controls were included in this study, with an experimental paradigm of upper limb isokinetic push-pull movements. The results revealed that $\textit {WC}_{\textit {dif}}$ were significantly higher in the stroke patient group compared to the healthy group. Moreover, the $\textit {TSE}_{\textit {dif}}$ of stroke group is higher than healthy group on the efferent pathway, but no difference on the afferent pathway. Utilizing the validated $\textit {CMC}_{\textit {dif}}$ indices, we developed a motor function assessment model that showed strong relation with clinical assessment outcomes ( ${R}^{{2}}={0}.{873}$ , ${p}={0}.{003}$ ). These findings provide a new insight to understand the mechanisms underlying CMC changes after stroke. The combined use of linear and nonlinear indicators enhances the potential of CMC for clinical motor function assessment in stroke patients.