The effect of peripheral nerve electrical stimulation on the corticospinal excitability

Abstract

Increasing excitability of the pathway between the primary motor cortex and the skeletal muscles might play an important role in promote functional motor recovery after central nervous system (CNS) damage. Peripheral nerve electrical stimulation (PES) effectively increases the excitability of this pathway in patients with CNS damage. Furthermore, PES combined with voluntary contraction or motor imagery is more effective than each intervention alone. However, the modulatory effect of PES on corticospinal excitability varies with the type of voluntary contraction performed. In healthy people, shortening contraction with PES increases corticospinal excitability, whereas isometric contraction with PES has no effect on excitability. On the other hand, PES parameter is a crucial factor for determining the extent of modulation of corticospinal excitability after PES. The application of train PES is a new method and is more effective than conventional PES in increasing excitability. In summary, both PES combined with voluntary contraction or motor imagery and train PES may promote functional motor recovery after CNS damage more than conventional PES does. However, further verification of the optimal parameter is necessary.