Subcutaneous Botulinum Toxin for Cutaneous Allodynia - Enriched Responder Trial

Pain Clinical Trial

Official title:

Subcutaneous Botulinum Toxin for Cutaneous Allodynia - Enriched Responder Trial

Clinical Trial Details — Status: Suspended

Administrative data

• NCT number: NCT00822926
• Other study ID #: SU-01072009-1499
• Secondary ID: 15601
• Status: Suspended
• Phase: N/A
• First received: January 14, 2009
• Last updated: May 14, 2013
• Start date: January 2009
• Est. completion date: December 2013

Study information

• Verified date: May 2013
• Source: Stanford University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Superficial injection of Botulinum toxin has been advocated for cosmetic purposes but has also been reported to be helpful for some pain conditions. The investigators have observed prolonged profound analgesia following subcutaneous superficial injection of Botulinum Toxin Type A (BTA) in patients with certain types of neuropathic pain. the investigators propose to study if addition of BTA extends pain relief compared to placebo when injected subcutaneously into areas of cutaneous allodynia (the property that a normally non-noxious stimulus is perceived as painful).

Description:

Patients with post-herpetic neuralgia, complex regional pain syndrome, and post-surgical neuromatous pain patients have marked cutaneous allodynia. Touching their skin with normally non-painful stimuli results in pain. Injected local anesthetics are often effective in providing temporary relief. In the course of clinical practice the investigators have observed that a number of patients with cutaneous allodynia have had marked persistent benefit from subcutaneous injection of Botulinum toxin Type A.

Rather than killing targeted neurons, Botulinum toxin type A inhibits release of acetylcholine from cholinergic nerve terminals in a prolonged but ultimately reversible manner. Neuropathic pain and its hallmark allodynia are classically difficult to treat. Standard treatment with tricyclic antidepressants, anti-epileptic drugs, opiates and spinal cord stimulation is frequently disappointing leaving patients with refractory pain. Surgical or percutaneous ablation of involved nerves has fallen out of favor among many due to disappointing results.

A pilot study is needed to assess the efficacy of superficially injected Botulinum Toxin type A for treatment of cutaneous allodynia and spontaneous pain among patients with neuropathic pain.

Recruitment information / eligibility

• Status: Suspended
• Enrollment: 20
• Est. completion date: December 2013
• Est. primary completion date: December 2013
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Moderate to severe pain (greater than 2/10) of duration more than 6 months despite previous therapy, excluding botox injection

• The patient exhibits at least 80% pain relief following injection of local anesthetic subcutaneously into scar as assessed by change in NRS

• Patient reports more than 3 weeks of greater than 50% pain relief from previous botox injection

• The patient reports the presence of hyperalgesia, allodynia, dysesthesia, or hypoesthesia surrounding the scar in the absence of the botox injection

• Age 18-100

• Ability to read, write, and converse in English, provide informed consent, and follow study procedures

Exclusion Criteria:

• Any neuromuscular disorder such as myasthenia gravis, eaton lambert, muscular dystrophy

• Any ongoing legal action related to their pain

• Allergy to local anesthetics

• Any ongoing disability claim

• Currently being treated for any severe psychiatric disorder, including anxiety or depression

• History of any adverse reaction to botulinum toxin

• History of botulism

• Untreated infection

• Coagulopathy

• (Females) - positive pregnancy test

• Surgery in the last 6 months

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Pain

Intervention

Drug:
• Botulinum Toxin Type A
Patients receive a subcutaneous injection of Botulinum Toxin Type A into the scar tissue
• Saline
Subcutaneous injection of saline into scar tissue

Locations

Country	Name	City	State
United States	Stanford University School of Medicine	Stanford	California

Sponsors (1)

Lead Sponsor	Collaborator
Stanford University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time to analgesic failure		Duration of trial	No
Secondary	Reduction in area of allodynia and hyperalgesia		duration of trial	No
Secondary	Improvement in psychosocial function as assessed by outcomes as dictated by the IMMPACT Guidelines		Duration of Trial	No
Secondary	Proportion of patients experiencing a reduction of 2 points or more on NRS, three weeks after injection, compared to baseline NRS		3 weeks after injection	No