tDCS Versus tsDCS for Endometriosis-related Chronic Pelvic Pain Treatment (DCSErCPP)

Transcranial Direct Current Stimulation (tDCS) vs Trans-spinal Direct Current Stimulation (tsDCS) for Endometriosis-related Chronic Pelvic Pain Treatment: A Single Center, Prospective, Randomized, Controlled, Parallel Group Pilot Study

The purpose of the study is to compare the analgesic effect of 2 mA anodal direct current stimulation on the right primary motor cortex (M1) (tDCS) with a similar stimulation on the spine (D10) (tsDCS) in healthy volunteers (HV) followed by a pilot study in patients suffering of endometriosis-related chronic pelvic pain (CPP)

- 2 groups of 5 HV will receive tDCS or tsDCS (2mA, anodal, 20min) and the thermonociceptive threshold will be measured before and after the stimulation over the abdomen (hypogastric). The HAD scale and SF-36 will also be tested. The treatment(s) that produces the greatest increase in pain thresholds will be chosen to treat 10 patients. - 10 patients suffering from endometriosis-related chronic pelvic pain will be treated by the most efficient treatment (tDCS or tsDCS) for 4 weeks (5 daily 20-min sessions per week), or, if no treatment modality was superior in HV, 5 patients will be treated by tDCS and 5 by tsDCS. Patients will fill in daily a dedicated diary 2 weeks before treatment, during the4-week treatment period and after this period as long as their pain level remains below 80% of their baseline pain intensity (VAS). Analgesic intake will also be monitored as well as HAD and SF-36 scores.

5 HV will be treated once with transcranial direct current stimulation (2mA, anodal, 20 minutes) over right primary motor cortex with the Direct Current (DC) Stimulator (NeuroConn. Germany)

5 HV will be treated once with transspinal direct current stimulation (2mA, anodal, 20 minutes) over the D10 spinal process with the Direct Current (DC) Stimulator (NeuroConn. Germany)

5 chronic pelvic pain patients will be treated with transcranial direct current stimulation (2mA, anodal, 20 minutes) over right primary motor cortex 5 days/week for 4 weeks with the Direct Current (DC) Stimulator (NeuroConn. Germany)

5 chronic pelvic pain patients will be treated with transspinal direct current stimulation (2mA, anodal, 20 minutes) over the D10 spinal process 5 days/week for 4 weeks with the Direct Current (DC) Stimulator (NeuroConn. Germany)

The DC stimulator manufactured by NeuroConn (Germany) will be used to deliver anodal direct current stimulation over the right primary motor cortex of healthy volunteers

The DC stimulator manufactured by NeuroConn (Germany) will be used to deliver anodal direct current stimulation over the D10 spinal process of healthy volunteers

The DC stimulator manufactured by NeuroConn (Germany) will be used to deliver anodal direct current stimulation over the right primary motor cortex of CPP patients

The DC stimulator manufactured by NeuroConn (Germany) will be used to deliver anodal direct current stimulation over the D10 spinal process of CPP patients

Inclusion Criteria: HV: good health. CPP patients: surgical diagnosis of endometriosis within the last 10 years; diagnosis of chronic pelvic pain (according to ACOG); mean VAS pain score >4 during severe episodes. Exclusion Criteria: HV: chronic pain disorder; no regular medication or illicit drug use. CPP patients: pregnancy; other medical or psychiatric condition interfering with pelvic pain assessment.