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Subcutaneous Botulinum Toxin for Cutaneous Allodynia

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified June 2012 by Sean Mackey, Stanford University.
Recruitment status was:  Active, not recruiting
Information provided by (Responsible Party):
Sean Mackey, Stanford University Identifier:
First received: July 28, 2008
Last updated: June 4, 2012
Last verified: June 2012
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 A Drug: Placebo - Saline

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

Resource links provided by NLM:

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

Primary Outcome Measures:
  • Time until 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: duration of trial ]

Estimated Enrollment: 70
Study Start Date: December 2007
Estimated Study Completion Date: January 2013
Estimated Primary Completion Date: October 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo - Saline Drug: Placebo - Saline
Subcutaneous Saline injection given at site of scar neuroma
Experimental: Botulinum Toxin Type A Drug: Botulinum Toxin A
Subcutaneous injection of Botulinum Toxin Type A into the patient's scar tissue

Detailed Description:

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 4/10) of duration more than 6 months despite previous therapy.

  • The patient exhibits at least 80% pain relief following injection of local anesthetic subcutaneously into scar as assessed by change in NRS
  • The patient reports the presence of hyperalgesia, allodynia, dysesthesia, or hypoesthesia surrounding the scar
  • Age 18-100
  • Ability to read, write, and converse in English, provide informed consent, and follow study procedures

Exclusion Criteria:

  1. Any neuromuscular disorder such as myasthenia gravis, eaton lambert, muscular dystrophy
  2. Any ongoing legal action related to their pain
  3. Allergy to local anesthetics
  4. A current or history of any severe psychiatric disorder
  5. History of any adverse reaction to botulinum toxin
  6. History of botulism
  7. Untreated infection
  8. Coagulopathy
  9. Females - positive pregnancy test
  10. Surgery within the past 6 months at the site of the painful scar
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Please refer to this study by its identifier: NCT00725322

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, Assistant Professor, Stanford University Identifier: NCT00725322     History of Changes
Other Study ID Numbers: SU-01072008-965
Study First Received: July 28, 2008
Last Updated: June 4, 2012

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 August 18, 2017