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NCT Number: NCT00725322

Subcutaneous Botulinum Toxin for Cutaneous Allodynia

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).

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Key information

Conditions

Pain Neurologic Manifestations Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Stanford University School of Medicine

Stanford, California, 94305, United States

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

  • Any neuromuscular disorder such as myasthenia gravis, eaton lambert, muscular dystrophy
  • Any ongoing legal action related to their pain
  • Allergy to local anesthetics
  • A current or history of any severe psychiatric disorder
  • History of any adverse reaction to botulinum toxin
  • History of botulism
  • Untreated infection
  • Coagulopathy
  • Females - positive pregnancy test
  • Surgery within the past 6 months at the site of the painful scar

Treatment and study plan

Botulinum toxin A

Drug

Subcutaneous injection of Botulinum Toxin Type A into the patient's scar tissue

Placebo - Saline

Drug

Subcutaneous Saline injection given at site of scar neuroma

Primary outcomes

  1. Time Until Analgesic Failure

    Time frame: Each participant was assessed for up to 224 days per intervention (injection) or until they returned to NRS baseline

    Participants made daily NRS reports via Palm Pilot, and "failure" was defined as (Pre-injection baseline NRS) - (Mean NRS for any 3 preceding days) ≤ 0; or 9 months

Secondary outcomes

  1. NRS Score Three Weeks After Injection

    Time frame: Three weeks after injection

    The NRS scores range from 0-100, where 0 indicated no pain and 100 indicated the worst pain.

Sponsors and collaborators

Lead sponsor

Stanford University

Other

Registry information

Important dates

Study start
2007
Primary completion
2013
Study completion
2013
First posted
Jul 30, 2008
Registry last updated
Oct 25, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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