Does Functional Electrical Stimulation for Foot Drop Strengthen Corticospinal Connections?
By Everaert, Dirk G.; Thompson, Aiko K.; Chong, Su Ling; Stein, Richard B.; Neurorehabilitation and Neural Repair,Publication Date: October 27, 2009 (Online First)
Study explored the effect of long-term use of a foot drop stimulator applying functional electrical stimulation (FES) on residual corticospinal connections in people with central nervous system disorders. Participants were 10 individuals with nonprogressive disorders such as stroke and 26 with progressive orders including multiple sclerosis (MS). Participants used a foot-drop stimulator for 3 to 12 months while walking in the community. Walking performance and electrophysiological variables were measured before and after FES use. From the surface electromyogram of the tibialis anterior muscle, the following were measurements were taken: (1) motor-evoked potential (MEP) from transcranial magnetic stimulation over the motor cortex, (2) maximum voluntary contraction (MVC), and (3) maximum motor wave (Mmax) from stimulating the common peroneal nerve. After using FES, MEP and MVC increased 50 percent and 48 percent, respectively, in the nonprogressive group, and 27 percent and 17 percent in the progressive group; these significant changes were positively correlated. Walking speed increased with the stimulator off, considered a therapeutic effect, by 24 percent in the nonprogressive and by 7 percent in the progressive group. The changes in Mmax were small and not correlated with changes in MEP. The study concludes that, based on the increases in MVC and MEP, regular use of a foot-drop stimulator strengthens activation of motor cortical areas and their residual descending connections, which may explain the therapeutic effect on walking speed.
Published by: Sage Publications (Website:http://www.sagepub.com)
American Society of Neurorehabilitation (Web Site: http://www.asnr.com )
Link to text: http://nnr.sagepub.com/cgi/rapidpdf/1545968309349939v1
