tDCS is a noninvasive brain stimulation technique that utilizes low amplitude direct currents applied via scalp electrodes to modulate the level of cortical excitability.Several studies have demonstrated that tDCS applied over the sensory-motor cortex has been able to decrease pain sensation and to increase pain threshold in healthy subjects and in chronic pain patients.~The aim of this study was to test whether daily sessions of anodal tDCS repeated for 5 consecutive days may be effective in reducing pain in a large number of chronic pain patients.~Patients will receive sham tDCS or real tDCS in a 5-day period of treatment in a randomized, sham controlled study. The participants will be divided to 2 groups of 50 each. One group will receive 5 days period of 20 min 2mA tDCS over the lt M1 and the other will receive sham stimulation. X week later the groups will switch to the other arm.~Pain will be measured using visual analog scale (VAS) for pain and the short form McGill questionnaire (SF-MPQ). Disability will be measured using the ( Pain Disability Index (PDI) of Life-54 scale (MSQoL-54). Depressive symptoms and anxiety will also be evaluated using the Center for Epidemiological Studies-Depression Scale and the State-trait Anxiety Inventory (STAI). Cognitive function will be mesured using minimental test. Evaluations will be performed at baseline, immediately after the end of treatment, and once a week during a 3-week follow-up period.
In the present study, the investigators intend to investigate whether anodal transcranial direct current stimulation (tDCS) may be effective in reducing pain in chronic pain patients.