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Subcutaneous Botulinum Toxin for Cutaneous Allodynia - Enriched Responder Trial

This study has suspended participant recruitment.
(Further enrollment is pending analysis of another trial)
Information provided by (Responsible Party):
Sean Mackey, Stanford University Identifier:
First received: January 14, 2009
Last updated: May 14, 2013
Last verified: May 2013
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).

Condition Intervention
Pain Drug: Botulinum Toxin Type A Drug: Saline

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Subcutaneous Botulinum Toxin for Cutaneous Allodynia - Enriched Responder Trial

Resource links provided by NLM:

Further study details as provided by Sean Mackey, Stanford University:

Primary Outcome Measures:
  • Time to analgesic failure [ Time Frame: Duration of trial ]

Secondary Outcome Measures:
  • Reduction in area of allodynia and hyperalgesia [ Time Frame: duration of trial ]
  • Improvement in psychosocial function as assessed by outcomes as dictated by the IMMPACT Guidelines [ Time Frame: Duration of Trial ]
  • Proportion of patients experiencing a reduction of 2 points or more on NRS, three weeks after injection, compared to baseline NRS [ Time Frame: 3 weeks after injection ]

Estimated Enrollment: 20
Study Start Date: January 2009
Estimated Study Completion Date: December 2013
Estimated Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo Drug: Saline
Subcutaneous injection of saline into scar tissue
Experimental: Botulinum Toxin Type A Drug: Botulinum Toxin Type A
Patients receive a subcutaneous injection of Botulinum Toxin Type A into the scar tissue

Detailed 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.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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
  Contacts and Locations
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Please refer to this study by its identifier: NCT00822926

United States, California
Stanford University School of Medicine
Stanford, California, United States, 94305
Sponsors and Collaborators
Stanford University
Principal Investigator: Ian R Carroll Stanford University
Principal Investigator: Sean Mackey Stanford University
  More Information

Responsible Party: Sean Mackey, Associate Professor, Stanford University Identifier: NCT00822926     History of Changes
Other Study ID Numbers: SU-01072009-1499
Study First Received: January 14, 2009
Last Updated: May 14, 2013

Additional relevant MeSH terms:
Somatosensory Disorders
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Botulinum Toxins
Botulinum Toxins, Type A
Acetylcholine Release Inhibitors
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Cholinergic Agents
Neurotransmitter Agents
Physiological Effects of Drugs
Neuromuscular Agents
Peripheral Nervous System Agents processed this record on July 24, 2017