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

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

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.

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.