Effects of Transcranial Direct Current Stimulation on Pain Perception

Study Overview
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Brief Summary
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The purpose of this study is to determine whether a new medical technology can temporarily alter pain perception. The new technology is called Transcranial direct current stimulation (tDCS).

Detailed Description
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Healthy subjects underwent thermal pain tolerance testing pre- and post intervention. The intervention includes either anodal, cathodal, or sham tDCS for 20 minutes during a pain cognitive intervention [either brief cognitive intervention (BCI) or general pain education]. The tDCS brand was the Phoresor-II Auto (Model PM850, Iomed, Salt Lake City Utah, USA) and the current was set to 2.0mA. Electrodes were 4x4 cm sponge electrodes soaked in sterile saline. For anodal and cathodal tDCS, One electrode was placed over the left DLPFC (F3 from the EEG 10-20 system) located via the Beam F3 measurement system and the other electrode was attached to the right shoulder. For sham tDCS, the device was turned on for 30 seconds to temporarily mimic tingling and skin sensations of real tDCS and then ramped-down to 0mA for the duration of the 20-minute session.

Official Title
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Effects of Transcranial Direct Current Stimulation on Pain Perception

Conditions
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Pain

Intervention / Treatment
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* Device: anodal tDCS
* Device: cathodal tDCS
* Device: sham tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Inclusion Criteria: 100 Health Individuals recruited from Charleston ,SC Exclusion Criteria: Can not be pregnant No history of Depression, chronic pain, Seizers, suicidal implanted metal devices, history of brain surgery, loss of consciousness.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: anodal tDCS plus BCI<br>Participants underwent Brief Cognitive intervention (BCI) during a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode electrode placed over the left DLPFC and the cathode electrode attached to the right shoulder (Brand Phoresor-II Auto) . BCI entails listening to a 3-minute audio recording designed to mimic key components of cognitive behavioral therapy (CBT) for pain. | Device: anodal tDCS<br>* a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode electrode placed over the left DLPFC and the cathode electrode attached to the right shoulder<br>* Other names: Phoresor-II Auto;|
| Active Comparator: anodal tDCS plus pain-education<br>Participants were provided pain education during a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode electrode placed over the left DLPFC and the cathode electrode attached to the right shoulder. Pain Education information included Pain Physiology, info on the Gate Theory of Pain, and Central Pain Processing. | Device: anodal tDCS<br>* a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode electrode placed over the left DLPFC and the cathode electrode attached to the right shoulder<br>* Other names: Phoresor-II Auto;|
| Experimental: cathodal tDCS plus BCI<br>Participants underwent Brief Cognitive intervention (BCI) during a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode attached to the right shoulder and the cathode electrode placed over the left DLPFC. BCI entails listening to a 3-minute audio recording designed to mimic key components of cognitive behavioral therapy (CBT) for pain. | Device: cathodal tDCS<br>* a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode attached to the right shoulder and the cathode electrode placed over the left DLPFC.<br>* Other names: Phoresor-II Auto;|
| Experimental: cathodal tDCS plus pain-education<br>Participants were provided pain education during a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode electrode attached to the right shoulder and the cathode electrode was placed over the left DLPFC. Pain Education information included Pain Physiology, info on the Gate Theory of Pain, and Central Pain Processing. | Device: cathodal tDCS<br>* a single 20-minute session of transcranial direct current stimulation (tDCS) with the anode attached to the right shoulder and the cathode electrode placed over the left DLPFC.<br>* Other names: Phoresor-II Auto;|
| Sham Comparator: sham tDCS plus BCI<br>Participants underwent Brief Cognitive intervention (BCI) during 20 minutes of sham tDCS. For sham, the device was turned on for 30 seconds to temporarily mimic tingling and skin sensations of real tDCS and then ramped-down to 0mA for the duration of the 20-minute session. | Device: sham tDCS<br>* Participants were provided pain education during 20 minutes of sham tDCS. For sham, the device was turned on for 30 seconds to temporarily mimic tingling and skin sensations of real tDCS and then ramped-down to 0mA for the duration of the 20-minute session<br>* Other names: Phoresor-II Auto;|
| Sham Comparator: sham tDCS plus pain-education<br>Participants were provided pain education during 20 minutes of sham tDCS. For sham, the device was turned on for 30 seconds to temporarily mimic tingling and skin sensations of real tDCS and then ramped-down to 0mA for the duration of the 20-minute session. Pain Education information included Pain Physiology, info on the Gate Theory of Pain, and Central Pain Processing. | Device: sham tDCS<br>* Participants were provided pain education during 20 minutes of sham tDCS. For sham, the device was turned on for 30 seconds to temporarily mimic tingling and skin sensations of real tDCS and then ramped-down to 0mA for the duration of the 20-minute session<br>* Other names: Phoresor-II Auto;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pre-Intervention Pain Tolerance | Participants will undergo comprehensive laboratory pain assessment including hot and cold, sensory and pain threshold assessment using the Method of Limits with the Pathway Thermo-sensory Analyzer System (Medoc Inc., NC) which is specifically designed for assessing laboratory pain perception. | Duration of the study visit, approximately 2 hours | 
| Post-Intervention Pain Tolerance | Participants will undergo comprehensive laboratory pain assessment including hot and cold, sensory and pain threshold assessment using the Method of Limits with the Pathway Thermo-sensory Analyzer System (Medoc Inc., NC) which is specifically designed for assessing laboratory pain perception. | Duration of the study visit, approximately 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants That Correctly Guessed Condition Assignment | Participants guessed whether they received real tDCS or Sham tDCS. The base-rate for correctly guessing real versus sham was 50%. | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Healthy Adults, Pain Perception