Combined Peripheral (BreEStim) and Central Electrical Stimulation (tDCS) for Neuropathic Pain Management - Spinal Cord Injury

Study Overview
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Brief Summary
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This study looks at the effect of combined breathing-controlled electrical stimulation (BreEStim) and transcranial direct current stimulation (tDCS) on neuropathic pain after spinal cord injury, amputation, or brain injury. The hypothesis is that a single session of combined BreEStim and tDCS will produce an additive analgesic effect. This record covers the study in a population of spinal cord injury patients. Note that this study will also enroll healthy volunteers, brain injury patients, and amputation patients and that this study as applied to these other populations will be covered in separate ClinicalTrials.gov records.

Official Title
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Combined Peripheral (BreEStim) and Central Electrical Stimulation (tDCS) for Neuropathic Pain Management

Conditions
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Pain Management

Intervention / Treatment
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* Device: BreEStim
* Device: tDCS
* Device: tDCS sham


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: between 18 and 75 years male and female subjects has neuropathic pain after traumatic spinal cord injury has chronic pain, >3 months is stable on oral pain medications at least two weeks. (patients are allowed to continue their pain medications, i.e., no change in pain medications.) Exclusion Criteria: currently adjusting oral pain medications for their neuropathic pain have pain, but not neuropathic (e.g., from inflammation at the incision wound of the residual limb or neuroma) have a pacemaker, or other metal and/or implanted devices have amputation in their arm(s) have spinal cord injury (SCI) involving impairment of arms have cognitive impairment from brain injury or are not able to follow commands, or to give consent have asthma or other pulmonary disease are not medically stable have preexisting psychiatric disorders alcohol or drug abuse have a history of seizures/Epilepsy, or taking benzodiazepines, anticonvulsants, and antidepressants. Mini-mental state examination (MMSE), a brief 30-point questionnaire test that is commonly used in the literature, will be used to screen for cognitive impairment. A brain injury patient with a score of 24 or lower on MMSE will be excluded.

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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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: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: BreEStim and tDCS sham, then combined BreEStim and tDCS<br>BreEStim is voluntary breathing controlled electrical stimulation. | Device: BreEStim<br>* BreEStim will applied for 10 to 20 minutes.<br>Device: tDCS<br>* tDCS will be applied for 20 minutes.<br>Device: tDCS sham<br> <br> |
| Experimental: Combined BreEStim and tDCS, then BreEStim and tDCS sham<br>BreEStim is voluntary breathing controlled electrical stimulation. tDCS is transcranial direct current stimulation. | Device: BreEStim<br>* BreEStim will applied for 10 to 20 minutes.<br>Device: tDCS<br>* tDCS will be applied for 20 minutes.<br>Device: tDCS sham<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain as Assessed by Visual Analogue Scale (VAS) | A Visual Analogue Scale (VAS) is a measurement instrument that tries to measure a characteristic or attitude that is believed to range across a continuum of values and cannot easily be directly measured. It is often used in epidemiologic and clinical research to measure the intensity or frequency of various symptoms. To allow a continuous assessment of pain, VAS uses a 10 cm line labelled at '0' with 'no pain' and '10' with 'worst pain'. The line is marked at a point corresponding to the assessment of the pain. | baseline, 10 minutes after tDCS, 10 minutes after BreEstim | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrical Pain Threshold | Trimmed surface electrodes (1 inch by 1 inch) were used to examine electrical pain thresholds upon application of electrical stimulation (electrical stimulator 7SA, Digitimer). To measure electrical pain threshold, a pair of electrodes was placed next to each other centered on the thenar eminence (which is a group of muscles on the palm of the human hand at the base of the thumb); the intensity of electrical stimulation was started from the sensation threshold level (determined in outcome measure 3) and increased in steps of 1 mA; and subjects were instructed to close their eyes and to say ''yes'' when they first felt electrical stimulation painful. The electrical pain threshold is the mA level at which a participant first felt electrical stimulation painful. To improve consistency among subjects, they were advised that the pain threshold level was equivalent to 1 on the 0-10 VAS scale. Three repetitions were made and the average was used as the electrical pain threshold. | baseline, 10 minutes after tDCS, 10 minutes after BreEstim | 
| Electrical Sensation Threshold | Trimmed surface electrodes (1 inch by 1 inch) were used to examine electrical sensation threshold upon application of electrical stimulation (electrical stimulator 7SA, Digitimer). To measure electrical sensation threshold, a pair of electrodes was placed next to each other centered on the thenar eminence (which is a group of muscles on the palm of the human hand at the base of the thumb); the intensity of electrical stimulation was started from zero and gradually increased in steps of 0.1 mA; and subjects were instructed to close their eyes and to say ''yes'' when they explicitly felt electrical stimulation. The electrical sensation threshold is the mA level at which a participant explicitly felt electrical stimulation. Three repetitions were made and the average was used as the electrical sensation threshold. | baseline, 10 minutes after tDCS, 10 minutes after BreEstim |