Transcranial Direct Current Stimulation (tDCS) is a noninvasive brain stimulation technique that utilizes low amplitude direct currents applied via scalp electrodes to apply currents to the brain and modulate the level of cortical excitability. tDCS applied over the dorsolateral prefrontal and motor cortex has been reported to be able to decrease pain sensation and to increase pain threshold in healthy subjects and is effective in reducing central chronic pain in patients with multiple sclerosis (PwMS.) In spite of the encouraging results of tDCS in PwMS, detailed mechanisms accounting for its analgesic effect have not yet been elucidated.