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Completed

NCT Number: NCT02161302

THE EFFECT OF tDCS IN THE TREATMENT OF CHRONIC PELVIC PAIN ASSOCIATED WITH ENDOMETRIOSIS

The purpose of this study is to determine if transcranial direct current stimulation (tDCS) is effective in the treatment of chronic pelvic pain associated with endometriosis

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Key information

Conditions

Chronic Pain Endometriosis Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Genital Diseases Genital Diseases, Female Neurologic Manifestations Pain Pathological Conditions, Signs and Symptoms Signs and Symptoms Urogenital Diseases

Age range

18 year–55 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Hospital de Clínicas de Porto Alegre

Porto Alegre, Rio Grande do Sul, 90035-903, Brazil

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • age > 18 years old, non-menopausal, with the diagnosis of endometriosis by videolaparoscopy and biopsy, able to understand and write the Portuguese language, in treatment with isolated progestin for at least one month, who have the worst daily pain in the analogue visual scale > 4 cm on most of the days in the last month

Exclusion criteria

  • left-handed women, endometriosis implantation in intestine, bladder or urether (surgical treatment indication), history of intense or frequent headache, chronic dermatologic disease, previous adverse effects to treatment with tDCS, seizures, severe cranial trauma with alteration of the cranial anatomy, metallic intracranial implants or pacemaker, history of pelvic inflammatory disease, non-compensated psychiatric disease, non-collaborative patients, history of neurologic, oncologic disease, heart, renal or hepatic failure.

Treatment and study plan

Transcranial direct current stimulation (tDCS)

Device

The stimulation will be administered with a pair of surface electrodes, sponge coated, soaked in saline. A battery-powered constant current stimulator will be used for this purpose (tDCS device Soterix 1X1). The stimulation is performed by placing the anodal electrode in the primary motor cortex (M1) and the cathodal one in the contralateral supraorbital area and it will use a 2 mA current.

Other names: tDCS

Sham Transcranial Direct Current Stimulation

Device

The sham tDCS consists of the same montage of the active tDCS, but the device is turned off 30 seconds after initiating stimulation (without letting the patient notice it). Rest of the montage is kept identical as the active one during the 20 minutes that the session lasts.

Other names: Sham tDCS

Primary outcomes

  1. Change in worst daily pain assessed with the visual analogue scale.

    Time frame: Once Daily. Start 7 days before treatment, everyday during treatment period and every day during follow-up period (total = 35 days)

    Patients will be asked to write down their worst pain level (assessed by the Visual Analogue Scale, self-administered) in a paper diary with different scores: global pain, pain during menses, pain during sexual intercourse, pain during urination, pain during defecation. They will also be asked to daily write the analgesic drug intake. Total evaluations: 35 days.

  2. Changes in motor cortex blood flow assessed by near infrared spectroscopy

    Time frame: Treatment Day 1 (before receiving the 1st session of tDCS); Day 15 (at the end of treatment period) and Day 29 (at the end of follow-up period)

    Motor cortex blood flow will be assessed before the first session of tDCS (on Treatment day 1), after the end of treatment period (Day 15) and after the follow-up period (Day 29). Total = 3 evaluations.

  3. Change in Functional Pain Scale

    Time frame: Once a week - Treatment Day 1, Day 8, Day 15, Day 22, Day 29

    The Functional Pain Scale will be assessed by the Brazilian Profile of Chronic Pain: Screen (B-PCP:S) once a week, as follows: on Treatment Day 1 (before the first session of tDCS, considered baseline), on Treatment Day 8, Day 15, Day 22, and Day 29. Total = 5 evaluations.

  4. Change in the temperature pain threshold

    Time frame: up to Day 29

    It will be assessed by the Quantitative Sensory Test (QST) in the dominant (right) forearm. The heat pain tolerance and pain threshold to the heat and the temperature defined as pain 6/10 by the participant. The temperature starts at 32°C, and it heat at a 1.0 °C/sec rate and cools down after a button is pressed or whenever it reaches the max temperature of 52°C. The participant will be asked to press the button at the first sensation of pain to determine the pain threshold; to press the button whenever she can not stand the heat anymore for the pain tolerance determination and, for last, to press the button at the temperature she fells pain equivalent to 6/10 in the numeric scale of pain. The pain threshold and the temperature of pain 6/10 will be determined by the arithmetic mean of 3 evaluations each. Total of 3 test days: Day 1 (before the first session of tDCS), after the end of the Treatment period (Day 15) and at the end of the follow-up period (Day 29).

  5. Change in effect of the descendent modulator system of pain

    Time frame: up to Day 29

    It will be assessed by the Conditioned Pain Modulation test (CPM). A nociceptive tonic conditioning stimulus - immersion of the non-dominant hand in cold water (0°C for 1 minute) - will be applied concomitant to the progressive thermal stimulus in the dominant forearm as applied in the QST pattern until it reaches the 6/10 pain temperature previously determined by the participant. It will be tested in Treatment Day 1 (before the first session of tDCS - considered baseline), after the end of the Treatment period (Day 15) and at the end of the follow-up period (Day 29) - Total = 3 evaluation.

Secondary outcomes

  1. Change in serum biomarkers level: The brain derived neurotrophic factor (BDNF) and interleukins

    Time frame: up to Day 29

    A blood sample will be collected to measure BDNF and interleukins on Treatment Day 1 (right before the first tDCS session - considered baseline), after the end of the treatment period (day 15,) and after the end of the follow-up period (day 29). Total = 3 evaluations

Other outcomes

  1. Depressive symptoms level

    Time frame: Treatment Day 1 (before receiving the 1st session of tDCS); Day 15 (at the end of treatment period) and Day 29 (at the end of follow-up period)

    Depression symptoms will be assessed by using the Beck II Inventory. It will be assessed before the first session of tDCS (on Treatment day 1), after the end of treatment period (Day 15) and after the follow-up period (Day 29). Total = 3 evaluations.

  2. Anxiety level

    Time frame: Treatment Day 1 (before receiving the 1st session of tDCS); Day 15 (at the end of treatment period) and Day 29 (at the end of follow-up period)

    Anxiety level will be assessed by State-Trait Anxiety Inventory (STAI), adapted to Brazilian Portuguese Language. It will be assessed before the first session of tDCS (on Treatment day 1), after the end of treatment period (Day 15) and after the follow-up period (Day 29). Total = 3 evaluations.

  3. Psychiatric diseases

    Time frame: 1day on patient screening

    Psychiatric diseases will be evaluated by the Structured Clinical Interview for DSM-IV (SCID) in the patient screening. Total = 1 evaluation

  4. Estradiol level

    Time frame: Treatment Day 1 (before receiving the 1st session of tDCS)

    Estradiol blood level will be measured on treatment Day 1 (before receiving the 1st session of tDCS). Total = 1 evaluation

  5. Adverse Effects

    Time frame: up to Day 29

    At the end of each tDCS session, the incidence of any adverse effects - paresthesia, headache, dizziness, nausea, neck pain, burns, redness or pain in the scalp, insomnia, abrupt humor changes and lack of concentration - will be questioned to the participant. Total = 10 evaluations

  6. Pain catastrophizing thoughts

    Time frame: Treatment Day 1 (before receiving the 1st session of tDCS); Day 15 (at the end of treatment period) and Day 29 (at the end of follow-up period)

    The level of catastrophic thinking will be assessed by the Pain Catastrophizing Scale on Treatment Day 1 (before receiving the 1st session of tDCS), after the treatment period (Day 15) and at the end of the follow-up period (Day29). Total = 3 evaluations

  7. Demographic data and comorbidities

    Time frame: Baseline

    Demographic data and comorbidities will be asked in the baseline (before the first session of tDCS). Total = 1 evaluation.

  8. Change in quality of life

    Time frame: Baseline and Day 15

    Quality of life will be assessed by the WHOQOL (World Health Organization Quality of Life), in Treatment Day 1 (before the first session of tDCS - considered baseline) and after the treatment period (Day 15). Total = 2 evaluations

Sponsors and collaborators

Lead sponsor

Hospital de Clinicas de Porto Alegre

Other

Registry information

Official study title

THE EFFECT OF TRANSCRANIAL DIRECT CURRENT STIMULATION (tDCS) IN THE TREATMENT OF CHRONIC PELVIC PAIN ASSOCIATED WITH ENDOMETRIOSIS

Acronym: tDCS

Important dates

Study start
2014
Primary completion
2015
Study completion
2016
First posted
Jun 11, 2014
Registry last updated
Jan 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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