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

January 14, 2026 updated by: Hospital de Clinicas de Porto Alegre

THE EFFECT OF TRANSCRANIAL DIRECT CURRENT STIMULATION (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

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Wolnei Caumo, MD, PhD
  • Phone Number: 51 3359 8083
  • Email: caumo@cpovo.net

Study Locations

  • Brazil
    • Rio Grande do Sul
      • Porto Alegre, Rio Grande do Sul, Brazil, 90035-903
        • Hospital de Clínicas de Porto Alegre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 55 years (Adult)

Accepts Healthy Volunteers

No

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Active tDCS
tDCS will be applied in the head of the patients in 20 minute sessions, daily from Monday to Friday for 2 weeks (10 sessions total). 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.
Device: transcranial direct current stimulation (tDCS)
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 Comparator: tDCS Sham
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.
Device: Sham Transcranial Direct Current Stimulation
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

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
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)
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).
up to Day 29
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.
up to Day 29
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.
Once Daily. Start 7 days before treatment, everyday during treatment period and every day during follow-up period (total = 35 days)
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.
Once a week - Treatment Day 1, Day 8, Day 15, Day 22, Day 29

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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
up to Day 29

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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.
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
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.
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)
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
1day on patient screening
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
Treatment Day 1 (before receiving the 1st session of tDCS)
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
up to Day 29
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
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)
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.
Baseline
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
Baseline and Day 15

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospital de Clinicas de Porto Alegre

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Wolnei Caumo, MD, PhD, Hospital de Clínicas de Porto Alegre

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2014

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2015

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2016

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 10, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 10, 2014

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 11, 2014

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 14-0092

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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