Chronic Pain, Endometriosis
Conditions
Keywords
Endometriosis, Transcranial Direct Current Stimulation, tDCS, Near Infrared Spectroscopy, NIRS, Chronic Pelvic Pain
Brief summary
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
Interventions
DEVICEtranscranial 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.
DEVICESham 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.
Sponsors
Hospital de Clinicas de Porto Alegre
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 55 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in motor cortex blood flow assessed by near infrared spectroscopy | 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. |
| Change in worst daily pain assessed with the visual analogue scale. | 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. |
| Change in Functional Pain Scale | 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. |
| Change in the temperature pain threshold | 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). |
| Change in effect of the descendent modulator system of pain | 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
| Measure | Time frame | Description |
|---|---|---|
| Change in serum biomarkers level: The brain derived neurotrophic factor (BDNF) and interleukins | 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
| Measure | Time frame | Description |
|---|---|---|
| Demographic data and comorbidities | Baseline | Demographic data and comorbidities will be asked in the baseline (before the first session of tDCS). Total = 1 evaluation. |
| Depressive symptoms level | 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. |
| Change in quality of life | 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 |
| Anxiety level | 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. |
| Psychiatric diseases | 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 |
| Estradiol level | 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 |
| Adverse Effects | 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 |
| Pain catastrophizing thoughts | 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 |
Countries
Brazil
Outcome results
None listed