Transcranial Direct Current Stimulation (tDCS) in Chronic Neuropathy

Study Overview
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Brief Summary
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This study evaluates the effect of additional transcranial direct stimulation (tDCS) on pain in patients with chronic neuropathic pain undergoing treatment with regional anaesthesiological techniques.

Detailed Description
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About 3.8 Million persons in Germany suffer from chronic pain with a relevant physical and social impairment representing approximately 7% of the population. Chronic pain conditions include patients with neuropathic pain such as trigeminal neuralgia, post-zoster pain or pain after amputations. There is a significant number of patients with pain without response to optimised drug therapy. Especially in these chronic pain patients there is data demonstrating maladaptive plasticity as pathophysiological evidence of structural changes in brain connectivity. Patients are treated with multimodal pain therapy concepts including interventional procedures with nerve infiltration techniques. One innovative therapeutic option for pain patients is transcranial direct current stimulation (tDCS): In recent clinical trials, patients reported on reduced overall pain intensity following tDCS stimulation series shown e.g. from Bolognini et al., Antal et al. and most recently from Volz and colleagues. However, there is no current data available evaluating a role of tDCS for patients with chronic neuropathic pain treated with regional anaesthesiological techniques. Objective: To evaluate effect of additional tDCS series on pain in patients with chronic neuropathic pain Primary study endpoint: relative reduction in pain (initial VAS measured versus VAS after completion of the therapy series) as a numeric value between 0 and 10.

Official Title
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Randomized Controlled Clinical Trial Evaluating Transcranial Direct Current Stimulation (tDCS) in Chronic Pain Patients With Neuropathy

Conditions
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Neuropathic Pain, Neuralgia

Intervention / Treatment
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* Device: cathodal transcranial direct current stimulation (tDCS)
* Device: sham transcranial direct current stimulation (tDCS)
* Device: anodal transcranial direct current stimulation (tDCS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with neuropathic pain with indication of regional anaesthesiological interventions Exclusion Criteria: <18 years of age Pregnancy Police custody Epilepsy Participation in another prospective clinical intervention study within the last 30 days

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Control<br>sham transcranial direct current stimulation (tDCS) | Device: sham transcranial direct current stimulation (tDCS)<br>* transcranial direct current stimulation (tDCS) is applied in active groups using a sham-stimulation including ramp up and ramp down of current.<br>|
| Experimental: cathodal stimulation<br>cathodal transcranial direct current stimulation (tDCS) | Device: cathodal transcranial direct current stimulation (tDCS)<br>* transcranial direct current stimulation (tDCS) is applied in active groups using cathodal active M1 stimulation. Active stimulation is applied with 2mA direct current via 20cm² electrodes.<br>|
| Experimental: anodal stimulation<br>anodal transcranial direct current stimulation (tDCS) | Device: anodal transcranial direct current stimulation (tDCS)<br>* transcranial direct current stimulation (tDCS) is applied in active groups using anodal active M1 stimulation. Active stimulation is applied with 2mA direct current via 20cm² electrodes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| relative pain intensity | relative reduction in pain intensity (initial VAS measured versus VAS after completion of the therapy series), VAS as a numeric value between 0 and 10. | after completion of therapy series, typically after 2 weeks of treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| acute pain reduction by tDCS application (relative reduciton measured as VAS after completion of tDCS stimulation versus initial VAS measured before stimulation) | relative reduction of pain intensity before and after each tDCS session and infiltration | 30 Minutes after application | 
| time to next regional-anesthesiological series | time until patients need additional regional-anesthesiological interventions | 6 months | 
| number of regional-anesthesiological interventions for pain control | number of required regional-anesthesiological interventions to achieve sufficient pain reduction | 10 days | 
| adverse events | Analysis of adverse reaction (skin redness, headache, concentration, other) | 1 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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neuropathic pain, neuralgia, tDCS, transcranial direct current stimulation