Cervical Application of the Direct Current Stimulation: Effects on Corticospinal Excitability

J Korean Assoc EMG Electrodiagn Med 2009;11(2):98-104.
Published online December 31, 2009.

Abstract

Objectives: To estimate the effects of the direct current (DC) stimulation applied at the cervical region oncorticospinal excitability
Methods: 11 healthy volunteers (26.8±3.31Yrs) participated in this study. A weak direct current (2 mA)was delivered on their cervical region using a constant current stimulator for 20 minutes. The magneticstimulation was applied over the primary motor cortex and motor evoked potential (MEP) was measuredat the abductor pollicis brevis (APB) muscle. Experimental protocol was composed of 3 sessions accordingto directions of the application; Anterior neck anode/posterior neck cathode (AC) stimulation, Anteriorcathode/posterior anode (CA) stimulation and Sham stimulation. The MEP amplitudes were measuredbefore, during and after the DC stimulation.
Results: Within AC stimulation and CA stimulation, each of MEP amplitude during stimulation and afterthe stimulation was significantly different from the initial amplitude. Between sessions, both of AC andCA stimulations were significantly different from Sham stimulation (P value<0.01), but it was notbetween AC and CA stimulation.
Conclusion: Cervical application of the DC stimulation increased the corticospinal excitability. Thiseffect maintained at least 10 minutes after stop of the stimulation. It might be effective tool for the corticospinaltract excitation.

Key Words: Direct current stimulation, Motor evoked potential, Corticospinal excitability