Botulinum Toxin Type A for Treating Allodynic Pain in SCI and MS

Study Overview
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Brief Summary
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This study will examine the efficacy of Botulinum Toxin Type A (Botox) in treating Allodynic-type neuropathic pain in people with spinal cord injury or multiple sclerosis. Neuropathic pain is pain initiated or caused by injury to or disease of the nervous system, and is common in spinal cord injury patients or people with multiple sclerosis. Allodynia is a type of neuropathic pain caused by something that normally would not cause pain, such as light touch, pressure from clothing, or bed sheets brushing against the skin. Botox has been used to treat the muscle overactivity that causes spasticity in spinal cord injured patients. It has been noticed to exert some analgesic(pain relieving) effect, and has recently been studied as a treatment for neuropathic pain. We want to see if Botox, injected intradermally, will relieve the symptoms of allodynic-type neuropathic pain. 24 volunteers are to be enrolled, with 16 receiving active treatment, and 8 controls receiving placebo.

Official Title
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The Efficacy of Botulinum Toxin Type A in the Treatment of Allodynic-Type Neuropathic Pain in People With Spinal Cord Injury or Multiple Sclerosis

Conditions
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Neuropathic Pain, Allodynia

Intervention / Treatment
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* Drug: Botulinum Toxin Type A
* Drug: Normal Saline for Injection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Fulfills the criteria for neuropathic pain causing allodynia according to IASP pain terminology. Allodynia that is resistant to, or has failed, the standard level of care measures for more that six months. Allodynia pain on a daily basis. Allodynia pain that scores at least 4/10 on a pain numerical scale. Other pain medications(including antidepressants and anticonvulsants)have been maintained at a stable dose for at least 2 months prior to enrollment. Ability to communicate in English. Exclusion Criteria: Presence of other pain syndromes (e.g.,fibromyalgia, ongoing peripheral neuropathic pain. Allergy to Botulinum Toxin Type A. Allergy to albumin. Use of Botulinum Toxin Type A for other treatment indications in the 3 months prior to enrollment. Renal failure. Hepatic failure. Neuromuscular junction disorders. Bleeding diathesis. Cognitive impairment, dementia, major depression or psychotic disorder. Pregnant or breastfeeding. Infection at the injection site. Active alchohol or substance abuse.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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 |
| --- | --- |
| Active Comparator: Arm 1: Botulinum Toxin Type A<br>200 units of Botulinum Toxin Type a will be administered intradermally to the allodynic area chosen for study.The allodynic area will be mapped, and the number of injections needed to cover the allodynic area without exceeding 40 injection sites will be determined. All participants will receive a cream formulation of lidocaine and prilocaine (EMLA) applied to the painful area 60 minutes before the injections to minimize any discomfort caused by the injections. | Drug: Botulinum Toxin Type A<br> <br> |
| Placebo Comparator: Arm 2: Normal Saline for Injection<br>Normal saline for intradermal injection will be prepared by the Investigational Pharmacy in a manner as to be indistinguishable from active drug. The allodynic area will be mapped so as to determine the number of injections needed to cover the whole allodynic area without exceeding 40 injection sites. All participants will receive a cream formulation of lidocaine and prilocaine (EMLA) applied to the painful area 60 minutes before the injections to minimize any pain caused by the injections. | Drug: Normal Saline for Injection<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brief Pain Inventory | The primary outcome measure will be the self-reported average pain intensity from each morning's record in a diary. The average(self-reported) pain intensity will be measured at the screening visit, then the daily diary will be dispensed. The diary will ask for the average pain intensity of the last 24 hours using an 11-point numerical scale, with 0 representing no pain and 10 representing the worst pain imaginable | Baseline and daily until study completion at 13 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neuropathic Pain Symptom Inventory | This scale rates the mean intensity of 10 neuropathic pain symptoms and their combination into 5 distinct dimensions during the last 24 hours on an 11-point (0-10) numerical scale | Baseline and follow-up visits(at weeks 1, 4, 8 and 13) | 
| The Hospital Anxiety and Depression Scale | 14 items scored as anxiety and depression | Baseline and follow-up visits (at weeks 1, 4, 8 and 13). | 
| Daily Sleep Interference Scale | Asks if pain interfered with sleep in the past 24 hours,using an 11-point scale (O-pain did not interfere with sleep, 10-pain completely interfered with sleep). Dispensed at baseline. | Baseline and daily during study period until week 13. | 
| Clinician Global Impression Scale | Assesses the clinician's impression of Efficacy and Tolerability of study medication using a 4-point scale, with 1 being Very good, and 4 being Poor | Final visit at week 13 | 
| Patient's Global Impression Scale | Measures the patients global impression of the efficacy and tolerability of the study medication on a 4-point scale, with 1 representing very good, and 4 representing poor | Final visit at week 13 |