Transcranial Direct Stimulation in Chronic Pelvic Pain

Study Overview
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Brief Summary
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The purpose of this study is to determine whether transcranial direct current stimulation (tDCS) is effective in reducing pain in subjects with chronic pelvic pain. Our hypothesis is that tDCS will decrease pain significantly when compared to sham stimulation.

Detailed Description
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The study encompasses two experiments: The first one involves patients with chronic pain, receiving 10 sessions of stimulation, active or sham (parallel design). The second experiment involves involves healthy subjects, receiving active or sham tDCS over the primary motor cortex (crossover design).

Official Title
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Investigation and Treatment of Central Nervous System Dysfunction in Chronic Pelvic Pain.

Conditions
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Pelvic Pain, Healthy

Intervention / Treatment
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* Device: Transcranial Direct Current Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Providing informed consent to participate in the study 18 to 64 years old Having symptoms of pelvic pain for more than 6 months with an average of 3 on a 0-10 VAS scale (for pelvic pain subjects only) No history of or current genitourinary tuberculosis as self reported No history of urethral cancer as self reported No history or current bladder malignancy, high grade dysplasia or carcinoma in situ as self reported No occurrence of ovarian, vaginal or cervical cancer in the previous 3 years as self reported No current vaginal infection as self reported No active herpes in previous 3 months as self reported No antimicrobials for urinary tract infections in previous 3 months as self reported Never treated with cyclophosphamide as self reported No radiation cystitis as self reported No neurogenic bladder dysfunction (due to a spinal cord injury, stroke, Parkinson's disease, multiple sclerosis, spina bifida or diabetic cystopathy) as self reported Absence of bladder, ureteral or urethral calculi for previous 3 months as self reported No urethritis for previous 3 months as self reported No urethral dilatation, cystometrogram, bladder cystoscopy with full anesthesia or bladder biopsy in previous 3 months as self reported Must not be pregnant Eligible to MRI according to MRI screening checklist No contraindications to tDCS: No history of alcohol or drug abuse within the past 6 months as self reported No use of carbamazepine as self reported Does not have severe depression (with a score of >30 in the Beck Depression Inventory) No history of neurological disorders as self reported No history of unexplained fainting spells as self reported, No history of head injury resulting in more than a momentary loss of consciousness as self reported Have had no neurosurgery as self reported No history of psychological disorders as self reported Must have the ability to feel pain as self reported

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 64 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: For the experiment in patients with pelvic pain, the design is parallel. For the experiment in healthy subjects, the design is crossover.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Active tDCS - pelvic pain patients<br>ACTIVE tDCS: Subjects will receive a total of 10 consecutive sessions of active tDCS over a two-week period (administered Monday - Friday). During each session, the anode electrode will be placed over the primary motor cortex of the predominantly painful side. | Device: Transcranial Direct Current Stimulation<br>* Chronic pain subjects will be randomized to receive either active or sham stimulation for the duration of the trial. The subject will receive 10 consecutive sessions at an intensity of 2mA with each session lasting 20 minutes. If the subject receives active stimulation the current will be applied for the full 20 minutes, while in the sham group current will only be applied for 30 seconds. In the healthy cohort, subjects will receive one session of active stimulation and one session of sham stimulation. The parameters will be the same as the pain subjects, at an intensity of 2mA for 20 minutes.<br>* Other names: tDCS, electrical stimulation;|
| Experimental: Sham tDCS - pelvic pain patients<br>SHAM tDCS: Subjects will receive a total of 10 consecutive sessions of sham tDCS over a two-week period (administered Mon-Fri). During each session, the anode will be placed over the primary motor cortex of the predominantly painful side. | Device: Transcranial Direct Current Stimulation<br>* Chronic pain subjects will be randomized to receive either active or sham stimulation for the duration of the trial. The subject will receive 10 consecutive sessions at an intensity of 2mA with each session lasting 20 minutes. If the subject receives active stimulation the current will be applied for the full 20 minutes, while in the sham group current will only be applied for 30 seconds. In the healthy cohort, subjects will receive one session of active stimulation and one session of sham stimulation. The parameters will be the same as the pain subjects, at an intensity of 2mA for 20 minutes.<br>* Other names: tDCS, electrical stimulation;|
| Experimental: Active tDCS - healthy<br>The healthy controls will undergo one day of treatment with active tDCS. All participants will receive both active and sham stimulation in a randomized order. | Device: Transcranial Direct Current Stimulation<br>* Chronic pain subjects will be randomized to receive either active or sham stimulation for the duration of the trial. The subject will receive 10 consecutive sessions at an intensity of 2mA with each session lasting 20 minutes. If the subject receives active stimulation the current will be applied for the full 20 minutes, while in the sham group current will only be applied for 30 seconds. In the healthy cohort, subjects will receive one session of active stimulation and one session of sham stimulation. The parameters will be the same as the pain subjects, at an intensity of 2mA for 20 minutes.<br>* Other names: tDCS, electrical stimulation;|
| Experimental: Sham tDCS - healthy<br>The healthy controls will undergo one day of treatment with sham tDCS. All participants will receive both active and sham stimulation in a randomized order. | Device: Transcranial Direct Current Stimulation<br>* Chronic pain subjects will be randomized to receive either active or sham stimulation for the duration of the trial. The subject will receive 10 consecutive sessions at an intensity of 2mA with each session lasting 20 minutes. If the subject receives active stimulation the current will be applied for the full 20 minutes, while in the sham group current will only be applied for 30 seconds. In the healthy cohort, subjects will receive one session of active stimulation and one session of sham stimulation. The parameters will be the same as the pain subjects, at an intensity of 2mA for 20 minutes.<br>* Other names: tDCS, electrical stimulation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Assessment | We use the Visual analogue scale (VAS) to measure pain. The VAS is ranged from 0 to 10, with 0 reffering to no pain and 10 reffering the the worst possible pain. We used the difference between post treatment minus baseline to compare the two treatments (active versus sham tDCS). | baseline and at 2 weeks | 
| Pressure Pain Threshold | Pressure pain threshold (PPT) is defined as the minimum force applied which induces pain. The change in pressure pain threshold (post minus pre intervention) is use for the analysis. | baseline and at 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quality of Life Scale (QOLS) | The questionnaire on quality of life was performed at the end of the treatment session and compared between the two groups (active and sham) in patients with pelvic pain (Exp. 1). The QOLS has 16 items (total scores ranging from 16 to 112) the highest scores corresponding the best QOL. | 2 weeks | 
| Clinical Global Impression - CGI | This scale measures illness severity and was performed on patients with pelvic pain (Exp. 1). The scale was performed at end of the treatment and compared between the two groups (real and sham). The scale is divided in 3 sub-scales: Severity of illness (0-7), global improvement (0-7) and efficacy index (0-16), total scores ranging from 0 to 30. The highest scores corresponding to lowest clinical improvement. | 2 weeks | 
| Visual Analogue Scale - Anxiety.This Scale Measures Patients' Level of Anxiety on a Scale (0-no Anxiety to 10-worst Anxiety Ever). It Was Performed at the End of the Treatment and Compared Between the 2 Groups (Real and Sham) in Patients With Pelvic Pain | The scale was performed at the end of the treatment and compared between the 2 groups (real and sham) in patients with pelvic pain (Exp. 1). | 2 weeks | 
| Mini Mental Scale - MMS | This scale measures patients cognitive impairment. It was performed at the end of the treatment and compared between the 2 groups (real and sham) in patients with pelvic pain (Exp. 1). It is a 30 points scale (total scores ranging from 0 to 30), the highest score corresponds to the highest cognitive status. | 2 weeks | 
| Beck Depression Inventory - BDI. | BDI is a questionnaire used for detecting depression. It was performed at the end of the treatment and compared between the 2 groups (real and sham) in patients with pelvic pain (Exp. 1). It is a 21-question multiple-choice self-report inventory (scores ranging from 0 to 63 - 0 corresponds to no symptom of depression). | 2 weeks | 
| Patient Global Assessment - PGA | This scale measures patient's assessment of general health. It was performed at the end of the treatment and compared between the 2 groups (real and sham) in patients with pelvic pain (Exp 1). The patient has to answer the question how is your health overall on a scale going from 0 to 10 (0 being the worst, 10 being the best). | 2 weeks | 
| Von Frey | This test is used to test subjects' sensitivity to a mechanical stimulus. It was performed before and and after the treatment and the difference (post minus pre) was compared between the 2 groups (real and sham) in patients with pelvic pain (Exp. 1). A set of filaments, typically from 0.008 grams force up to 300 grams force, is applied on the patients' skin. The mechanical threshold is defined as the moment when the patient detects the stimulus. | baseline and at 2 weeks | 
| Pain Pressure Threshold Test - PPT | Pressure pain threshold (PPT) is defined as the minimum force applied which induces pain.This test was applied before and after the treatment and the difference (post minus pre) was compared between the 2 groups (real and sham) in patients with pelvic pain (Exp 1). | baseline and at 2 weeks | 
| Diffuse Noxious Inhibitory Controls - DNIC. | DNIC occurs when response from a painful stimulus (pain pressure threshold - PPT) is inhibited by another noxious stimulus (cold water). The difference between baseline and post treatment was compared between the 2 groups (real and sham) in patients with pelvic pain (Exp. 1). | baseline and at 2 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Transcranial direct current stimulation, Chronic Pelvic Pain