High Definition Transcranial Direct Current Stimulation Motor Cortex Versus Insula

Study Overview
=================
Brief Summary
-----------------
Brain stimulation is a technique that can alter cortical function and thus be suitable for treating pain. This is especially when pain is chronic and associated with functional and even structural reorganization of the central nervous system. The idea of using invasive and noninvasive brain stimulation for pain relief is not new. Studies from the 1950s have investigated the brain stimulation for therapeutic use. Direct implantation of electrodes on the cerebral cortex has been carried out by Tsubokawa and colleagues in Japan. Although reported to be effective, it is invasive and involves the implantation of a foreign body into the cranium. Recent advancements in the techniques of non-invasive brain stimulation have improved and have measurable modulatory effects making this an attractive alternative for treating pain

Detailed Description
-----------------
Repetitive transcranial magnetic stimulation and transcranial direct current stimulation are currently the two main methods of non-invasive brain stimulation under investigation. Stimulation of the primary motor cortex has been reported to relieve neuropathic, musculoskeletal, visceral pain as well as headaches and migraine. Other parameters of stimulation have shown encouraging results. For example, stimulation of the secondary somatosensory cortex was also reported to relieve chronic visceral pain. However, there are numerous unanswered questions regarding these techniques. This research project is an attempt to answer some of these questions: Which pain conditions can be alleviated by non-invasive brain stimulation? What are the best parameters for stimulation- method: transcranial direct current stimulation or repetitive transcranial magnetic stimulation transcranial or Alternating Current Stimulation High-Definition transcranial direct current stimulation or conventional transcranial direct current stimulation? which area to stimulate? Primary motor cortex, insula? Will other forms of treatment such as pharmacotherapy, peripheral nerve stimulation or multi-disciplinary pain management enhance the effectiveness of non-invasive brain stimulation

Official Title
-----------------
The Effects of High Definition Transcranial Direct Current Stimulation Over Primary Motor Cortex Versus Insular Cortical Targets on Experimental Capsaicin Induced Hyperalgesia and Pain in Healthy Volunteers

Conditions
-----------------
Pain

Intervention / Treatment
-----------------
* Device: HD tDCS active motor cortex
* Device: HD tDCS active insula cortex
* Device: HD tDCS sham motor cortex
* Other: Capsaicin cream


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Able to give informed consent to participate in the study. Male and female University Undergraduate, Postgraduate and staff in the Department of Psychology. American society of anesthesiology scores I to II patients. Exclusion Criteria: the participant who has any history of: an adverse reaction to brain stimulation. a seizure an unexplained loss of consciousness a stroke serious head injury surgery to their head any brain related, neurological illnesses any illness that may have caused brain injury frequent or severe headaches metal in your head (outside the mouth) such as shrapnel, surgical clips, or fragments from welding any implanted medical devices such as cardiac pacemaker's or medical pumps taking any analgesic medications in the past 24 hours pregnancy anyone in your family has epilepsy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 70 Years

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

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

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

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: HD tDCS sham motor cortex<br>the intervention 10 participants will be subjected to1.5 gram of Capsaicin cream 0.075% concentration for 30 min then participants will be subjected to sham stimulation targeting motor cortex area using the high-definition transcranial direct current stimulation device by starting stimulation for 30 seconds then stop stimulation for 20 min | Device: HD tDCS sham motor cortex<br>* the intervention 10 participants will be subjected to1.5 gram of Capsaicin cream 0.075% concentration for 30 min then participants will be subjected to sham stimulation targeting motor cortex area using the high-definition transcranial direct current stimulation device by starting stimulation for 30 seconds then stop stimulation for 20 min<br>Other: Capsaicin cream<br>* Capsaicin cream<br>|
| Active Comparator: HD tDCS active motor cortex<br>the intervention will be 10 participants will be subjected to 1.5-gram of Capsaicin cream 0.075 concentration for 30 min then participants will be subjected to active stimulation targeting motor cortex area with the high-definition transcranial direct current stimulation device with current intensity 2 milliampere for 20 min | Device: HD tDCS active motor cortex<br>* the intervention will be 10 participants will be subjected to 1.5-gram of Capsaicin cream 0.075 concentration for 30 min then participants will be subjected to active stimulation targeting motor cortex area with the high-definition transcranial direct current stimulation device with current intensity 2 milliampere for 20 min<br>Other: Capsaicin cream<br>* Capsaicin cream<br>|
| Active Comparator: HD tDCS active insula cortex<br>the intervention will be 10 participants will be subjected to 1.5 gram of Capsaicin cream 0.075 concentration for 30 min then participants will be subjected to active stimulation targeting Insular cortex area with the high-definition transcranial direct current stimulation device, with current intensity 2milliampere for 20 min | Device: HD tDCS active insula cortex<br>* the intervention will be 10 participants will be subjected to 1.5 gram of Capsaicin cream 0.075 concentration for 30 min then participants will be subjected to active stimulation targeting Insular cortex area with the high-definition transcranial direct current stimulation device, with current intensity 2milliampere for 20 min<br>Other: Capsaicin cream<br>* Capsaicin cream<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain severity assessment using Numerical Rating Scale (NRS score from 0-100) | we will put the capsaicin cream for 30 min at an area of 9 cm2 then we will assess the pain score throughout this time of application of the cream every 5 min | 30 min after capsaicin cream application and at the end of the HD tDCS session and one hour after study | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| map area of sensitization caused by application of capsaicin cream | The area of sensitization using calibrated Neurotip test using the spring mechanism which will exert a force of 40 gm so we will detect the change in sensation to the pin brick in the area of cream application | 30 min after the capsaicin cream application and at the end of HD tDCS sessionand one hour after study |