Effectiveness of Transcranial and Suboccipital Direct Current Stimulation on Endogenous Pain Modulation System in Healthy Volunteers.
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 40
- Locations
- 2
- Primary Endpoint
- Conditioned Pain Modulation
Study Overview
Brief Summary
Randomized controlled trial, in parallel with cross-control design. Two groups of healthy subjects will be randomly selected to transcranial stimulation group or suboccipital stimulation group. Each group receive in a randomized order a real direct current session and a sham session. The study is based on the hypothesis that the application of direct current sitmulation applied at the suboccipital level produce higher modifications on endogenous pain modulation system than transcranial stimulation.
Detailed Description
The development of the project will be based on the Declarations of the World Medical Association of Helsinki. Every subject will be informed about the nature of the study, willingness to participate, the proposed objectives, as well as possible adverse effects that may occur in its implementation. Every subject will be asked to give their signed consent to participate in the study. The study will be suspended at any time, if the patient wishes.
Healthy volunteers will be recruited from the city of Toledo, between the ages of 18 and 40. The detection and selection of the sample will be carried out between the students of the University of Castilla-La Mancha and personnel of the Hospital Nacional de Parapléjicos who meet the inclusion criteria and give their consent voluntarily to participate in the study.
The calculation of the sample size will be carried out using the G * Power software program (version 3.1), for clinical studies with two intervention groups. Conditioned pain modulation will be chosen as the primary outcome variable. Assuming an α level of 0.05 and a statistical power of 85%, with a moderate effect size for the ANOVA test (0.25).
The experiment will be carried out in the clinical laboratory of the Sensory-Motor Function Research Group of the Hospital Nacional de Parapléjicos. Under attenuated sound conditions, and at a stable temperature in the range of (22 °C-26 °C).
In the first session of the study, a small interview will be carried out to determine if there is any exclusion criterion. The initial measurements will consist of sociodemographic variables and psychological variables, which will then be used to categorize groups and analyze covariates. A parallel randomized controlled trial with cross-control design is proposed. Two groups of healthy subjects will be randomly selected to transcranial direct current stimulation (DCS) group or suboccipital DCS group. Each group receive in a randomized order and with a double blind design a real direct current session and a sham session. An assessment is made before and after each intervention.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Double (Investigator, Outcomes Assessor)
Masking Description
Blinding of the assessor: all the assessments will be made by a different researcher who apply all the interventions. Assessor will not have vision of the place where the electrodes are located neither the parameters used.
Blinding of the subjects: Although subjects will be blinded to the hypothesis of the study, the transcranial and suboccipital location of the electrodes cannot be blinded. Direct current and sham stimulation will be blinded. For the sham condition subjects will feel the stimulation sensation for 30 seconds and then the stimulator will turn off. The same equipment, identical electrodes, and cables will be used. In addition, subjects will not have a view of the computer screen.
Blinding of the person who apply the intervention: Although transcranial and suboccipital conditions cannot be blinded. The direct current and sham stimulation will be apply by the blind-mode of the stimulator using locking codes.
Eligibility Criteria
- Ages
- 18 Years to 40 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Age between 18 and 40 years.
- •Healthy volunteers (without neurological injury and no history of pain in the last 6 months).
- •Ability to perform all clinical test and understand the process of the study, as well as obtaining informed consent.
- •Tolerance to the application of electrotherapy.
Exclusion Criteria
- •Previous history of surgical intervention at the cervical level.
- •Have been treated with an electric current similar to that applied prior to the intervention.
- •Sensitivity altered in the area of application of the intervention.
- •No commitment to continuity.
- •History of neuromuscular disease.
- •Epilepsy.
- •Injuries, surgery or pain affecting the upper limb.
- •Material of osteosynthesis at the cervical level.
- •Diabetes.
- •History of cancer.
- •Cardiovascular disease.
- •Presence of pacemakers or any other implanted electrical device.
- •Take medication during the study and in the 7 days prior to the study.
- •Consumption of narcotic substances during the study and in the 7 days prior to the study.
- •Presence of tattoos or any other external agent introduced in the treatment and assessment area (hand).
- •Pregnancy.
- •Presence of severe and frequent headaches.
- •Ulcers or scars in the skin at the location of the electrodes
Outcomes
Primary Outcomes
Conditioned Pain Modulation
Time Frame: Baseline at 0 min
For this protocol the test stimulus (TS) and the conditioning stimulus (CS) will be applied sequentially (first CS, followed by TS), heterotopic, and contralateral. The CS temperature will be 12 °C on the cold pressor test to induce a perception of pain. The subjects will have to submerge the non-dominant hand in the cold water bath for 30s, and evaluate the CS-induced pain intensity at 10, 20, and 30s (t1, t2 and t3 respectively). After assessing CS-induced pain intensity at the 30s of immersion participants will withdraw their hand from the water bath, and will have to fix their attention to the dominant hand where TS was immediately applied. The TS-induced pain assessment at 10, 20, and 30s (t1, t2 and t3).
Change from baseline Conditioned Pain Modulation
Time Frame: At 30 min
For this protocol the test stimulus (TS) and the conditioning stimulus (CS) will be applied sequentially (first CS, followed by TS), heterotopic, and contralateral. The CS temperature will be 12 °C on the cold pressor test to induce a perception of pain. The subjects will have to submerge the non-dominant hand in the cold water bath for 30s, and evaluate the CS-induced pain intensity at 10, 20, and 30s (t1, t2 and t3 respectively). After assessing CS-induced pain intensity at the 30s of immersion participants will withdraw their hand from the water bath, and will have to fix their attention to the dominant hand where TS was immediately applied. The TS-induced pain assessment at 10, 20, and 30s (t1, t2 and t3).
Secondary Outcomes
- Baseline Pressure Pain Threshold(at 10 min)
- Change from baseline Pressure Pain Threshold(at 40 min)
- Baseline Temporal Summation(At 5 min)
- Change from baseline Temporal Summation(At 35 min)