Analgesic Effect of Non Invasive Stimulation : Transcranial Direct Current Stimulation of Opercular-insular Cortex

Study Overview
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Brief Summary
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The aim of this study is to evaluate, versus placebo, the analgesic efficacy of the opercular-insular cortex stimulation with Transcranial Direct Current Stimulation (tDCS), in both healthy subjects and chronic neuropathic pain patients. In healthy subjects analgesia by tDCS will be assessed using both laser stimuli and cold pressor test. In patients the assessment regards their chronic pain (ratings for ongoing, evoked and paroxysmal pain, sleep and fatigue). Opercular-insular stimulation is obtained via a combined 6-electrode montage and by bi-vestibular stimulation (since vestibular pathways reach the posterior insular cortex). In patients, three separate conditions (two active and one sham) will be tested in randomised order. In healthy subjects, two other conditions are added to control for attention and distraction confounders.

Official Title
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Transcranial Direct Current Stimulation (tDCS) for Neuropathic Chronic Pain : Study of the Opercular-insular Cortex Stimulation

Conditions
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Neuropathic Pain

Intervention / Treatment
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* Device: transcranial direct current stimulation of opercular-insular cortex - anodal active tDCS session
* Device: transcranial direct current stimulation of opercular-insular cortex - active control session
* Device: transcranial direct current stimulation of opercular-insular cortex - sham control session.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy subjects aged from 18 to 70 years, male or female, with social security protection, fully informed and having given their written consent. patients aged from 18 to 80 years, male or female, with social security protection , fully informed and having given their written consent. pharmacoresistant neuropathic pain during at least one year, without any change of the pharmacological treatment since at least one month Exclusion Criteria: In healthy subjects only: history of chronic pain analgesic medication within 24h before stimulation For patients only: new analgesic treatment within 1 month before consent for both: drug addiction, headache, epilepsy ferromagnetic intracranial device implanted stimulator recent neurosurgery and open wound of the scalp. absence of contraceptive method for women of childbearing age

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: patients<br> | Device: transcranial direct current stimulation of opercular-insular cortex - anodal active tDCS session<br>* transcranial direct current stimulations of opercular-insular cortex. Three sessions separated by a minimum of 2 weeks, with three different conditions: one session with anodal active tDCS, one with active control, and one with sham control.<br>Device: transcranial direct current stimulation of opercular-insular cortex - active control session<br>* transcranial direct current stimulations of opercular-insular cortex. Three sessions separated by a minimum of 2 weeks, with three different conditions: one session with anodal active tDCS, one with active control, and one with sham control.<br>Device: transcranial direct current stimulation of opercular-insular cortex - sham control session.<br>* transcranial direct current stimulations of opercular-insular cortex. Three sessions separated by a minimum of 2 weeks, with three different conditions: one session with anodal active tDCS, one with active control, and one with sham control.<br>|
| Active Comparator: healthy subjects<br> | Device: transcranial direct current stimulation of opercular-insular cortex - anodal active tDCS session<br>* transcranial direct current stimulations of opercular-insular cortex. Three sessions separated by a minimum of 2 weeks, with three different conditions: one session with anodal active tDCS, one with active control, and one with sham control.<br>Device: transcranial direct current stimulation of opercular-insular cortex - active control session<br>* transcranial direct current stimulations of opercular-insular cortex. Three sessions separated by a minimum of 2 weeks, with three different conditions: one session with anodal active tDCS, one with active control, and one with sham control.<br>Device: transcranial direct current stimulation of opercular-insular cortex - sham control session.<br>* transcranial direct current stimulations of opercular-insular cortex. Three sessions separated by a minimum of 2 weeks, with three different conditions: one session with anodal active tDCS, one with active control, and one with sham control.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| In healthy subjects : Change in subjective pain and (when applicable) in cortical evoked potentials with pain scale |  | just before the tDCS session at Day 0 | 
| In patients : Changes in daily ratings of global pain |  | just before the tDCS session at Day 0 | 
| In healthy subjects : Change in subjective pain and (when applicable) in cortical evoked potentials |  | just after the tDCS session at Day 0 | 
| In patients : Changes in daily ratings of global pain |  | just after the tDCS session at Day 0 | 
| In patients : Changes in daily ratings of global pain |  | at week 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ongoing pain with pain scale |  | just before the tDCS session at Day 0 | 
| ongoing pain with pain scale |  | just after the tDCS session at Day 0 | 
| ongoing pain as assessed by daily ratings |  | during one week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Neuropathic Pain, Drug Resistance, opercular-insular cortex, Transcranial Direct Current Stimulation