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Updated: Aug 2, 2026
Corticospinal Excitability Modulation During Action Observation
Published on: December 31, 2013
Cortico-muscular and cortico-cortical coherence changes resulting from Perampanel treatment in patients with cortical
S Franceschetti1, E Visani2, D Rossi Sebastiano1
1Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
Objective:
To investigate the mechanisms by which Perampanel (PER) reduces the severity of action myoclonus, we studied on MEG signals the changes occurring in cortico-muscular coherence (CMC) and cortico-cortical connectivity in patients with progressive myoclonus epilepsies.
Methods:
The subjects performed an isometric extension of the hand; CMC and cortico-cortical connectivity were assessed using autoregressive models and generalized partial-directed coherence. The contralateral (Co) sensors showing average CMC values >0.7 of the maximum (set to 1) were grouped as central (C) regions of interest (ROI), while adjacent sensors showing CMC values >0.3 were grouped as Surrounding (Sr) ROIs.
Results:
Under PER treatment, CMC decreased on Co C and Sr ROIs, but also on homologous ipsilateral (Ip) ROIs; out-degrees and betweenness centrality increased in Co ROIs and decreased in Ip ROIs. The flow from Ip to Co ROIs and from activated muscles to Ip C ROI decreased.
Conclusion:
The improvement of myoclonus corresponded to decreased CMC and recovered leadership of the cortical regions directly involved in the motor task, with a reduced interference of ipsilateral areas.
Significance:
Our study highlights on mechanisms suitable to treating myoclonus and suggests the role of a reduced local synchronization together a better control of distant synaptic effects.
Insights
Perampanel (PER) treatment reduced action myoclonus by decreasing cortico-muscular coherence (CMC) and improving cortical control. This suggests reduced local synchronization and better distant synaptic regulation are key treatment mechanisms.
Area of Science:
- Neuroscience
- Epileptology
- Biomedical Engineering
Background:
- Action myoclonus in progressive myoclonus epilepsies (PME) presents significant challenges.
- Understanding the neural mechanisms underlying Perampanel (PER) efficacy is crucial for optimizing treatment.
Purpose of the Study:
- To elucidate the neurophysiological mechanisms by which Perampanel (PER) alleviates action myoclonus severity.
- To investigate changes in cortico-muscular coherence (CMC) and cortico-cortical connectivity during PER treatment in PME patients.
Main Methods:
- Magnetoencephalography (MEG) signals were analyzed during an isometric hand extension task.
- Autoregressive models and generalized partial-directed coherence assessed CMC and cortico-cortical connectivity.
- Defined contralateral (Co) and ipsilateral (Ip) regions of interest (ROIs) based on CMC values.
Main Results:
- PER treatment led to decreased CMC in both contralateral (Co) and ipsilateral (Ip) ROIs.
- Increased out-degrees and betweenness centrality were observed in Co ROIs, while they decreased in Ip ROIs.
- Reduced information flow from Ip to Co ROIs and from muscles to Ip ROIs was noted.
Conclusions:
- Improved myoclonus correlated with reduced CMC and restored cortical control in task-relevant areas.
- PER treatment appears to facilitate reduced local synchronization and enhanced control over distant synaptic effects.
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