Analgesic Effect of Non Invasive Stimulation : Comparison of rTMS and tDCS Efficacy

Study Overview
=================
Brief Summary
-----------------
The aim of this study is to compare analgesic efficacy of two non invasive techniques based on motor cortex stimulation in neuropathic pain patients. High frequency repetitive transcranial magnetic stimulation (HF-rTMS) of primary motor cortex has been demonstrated to induce an analgesic effect significantly different from placebo; this effect is clinically useful if rTMS sessions are applied daily during five consecutive days. Transcranial direct current stimulation (tDCS) is a new approach of non invasive cortical stimulation but its efficacy in neuropathic pain has been not yet established. The investigators propose to compare the analgesic effect of 5 tDCS sessions applied daily to a similar protocol using HF-rTMS. In parallel to the clinical therapeutic evaluation, functional-MRI will be performed before and after the five sessions of rTMS and tDCS, in order to reveal the potential plasticity induced within motor somatotopic map of the primary motor cortex.

Official Title
-----------------
Non-invasive Cortical Stimulation for Pharmacoresistant Neuropathic Pain: rTMS Versus tDCS

Conditions
-----------------
Pharmacoresistant Neuropathic Pain

Intervention / Treatment
-----------------
* Device: Repetitive Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: patients aged from 18 to 80 years, male or female, 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: drug addiction, headache, epilepsy history ferromagnetic intracranial device implanted stimulator absence of contraceptive method for women of childbearing age

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: rTMS; tDCS<br> | Device: Repetitive Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation<br>* Five sessions of HF-rTMS or tDCS applied daily during 5 consecutive days<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline in Pain at the end of the stimulation week Change from Baseline in Pain at the end of the first post-stimulation week Change from Baseline in Pain at the end of the second post-stimulation week |  | Here the Time Frames : Baseline; 1 week; 2 week; 3 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| objective evaluation of sleep quality | actimetry measures | Change from Baseline in percentage of sleep time at the end of the stimulation week; at the end of the first post-stimulation week; and at the end of the of the second post-stimulation week | 
| subjective evaluation of sleep quality using a numerical auto-evaluation scale | the patient is asked to evaluate each day the quality of his sleep using a numerical scale from 0 to 10. | Change from Baseline in level of tiredness at the end of the stimulation week;at the end of the first post-stimulation week; and at the end of the second post-stimulation week | 
| nociceptive and non-nociceptive thresholds | Electrical stimulation of variable intensities applied on the hand | Change from Baseline in nociceptive threshold after the first day of stimulation;after the fifth day of stimulation;Change from Baseline in non-nociceptive threshold after the first day of stimulation;and after the fifth day of stimulation | 
| evaluation of motor cortex plasticity | displacement of activation locus found after voluntary movements; comparison of the plastic and analgesic effects of rTMS or tDCS | Change from Baseline in three-dimensional location of the activation peaks at the end of the stimulation week | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
pain, neuropathic, cortical stimulation, motor cortex, plasticity, rTMS, tDCS