Human Motor Plasticity Induced by Mirror Visual Feedback

Authors:
  • SKSatoko Koganemaru
    Satoko Koganemaru
  • MTMohamed Nasreldin Thabit
    Mohamed Nasreldin Thabit
  • HFHidenao Fukuyama
    Hidenao Fukuyama
  • TKToshio Kawamata
    Toshio Kawamata
Open Access
Publisher website
Google Scholar
Abstract
The clinical use of mirror visual feedback (MVF) was initially introduced to alleviate phantom pain, and has since been applied to the improvement of hemiparesis following stroke. However, it is not known whether MVF can restore motor function by producing plastic changes in the human primary motor cortex (M1). Here, we used transcranial magnetic stimulation to test whether M1 plasticity is a physiological substrate of MVF-induced motor behavioral improvement. MVF intervention in normal volunteers using a mirror box improved motor behavior and enhanced excitatory functions of the M1. Moreover, behavioral and physiological measures of MVF-induced changes were positively correlated with each other. Improved motor performance occurred after observation of a simple action, but not after repetitive motor training of the nontarget hand without MVF, suggesting the crucial importance of visual feedback. The beneficial effects of MVF were disrupted by continuous theta burst stimulation (cTBS) over the M1, but not the control site in the occipital cortex. However, MVF following cTBS could further improve the motor functions. Our findings indicate that M1 plasticity, especially in its excitatory connections, is an essential component of MVF-based therapies.

This publication has 64 references indexed in Scilit: