Abstract
This report describes effect of facilitation of motor evoked potential (MEP) during application of weak (i. e., below the muscle contraction threshold) electrical stimulation on the peripheral nerve, a process known as Subthreshold Therapeutic Electrical Stimulation (STES). The MEP measurement system consisted of an electrical stimulator, a magnetic stimulator, EMG amplifier, electrical stimulation artifacts eliminator and computer. Magnetic stimulation was applied to the motor cortex using a circular stimulation coil; STES, to the common peroneal nerve using a surface electrode. To avoid electrical stimulation artifacts on MEP, the magnetic-stimulation pulse phase was synchronized with the electrical-stimulation pulse phase by computer on the basis of calculated MEP latency. During application of STES to 6 healthy subjects, MEP was recorded from the anterior tibial muscle using a surface electrode. In increasing of STES level, MEP showed enhanced amplitude in all subjects. Integrated MEP (IMEP) was increased significantly by the application of over 40 [%] levels STES and IMEP was maximized by the application 90 [%] STES. The results of this study demonstrated effect of facilitation of MEP during application of weak electrical stimulation to the peripheral nerve.
