Botulinum Toxin Injections for Thoracic Outlet Syndrome

University of British Columbia

Status and phase: Unknown; Phase 1

Conditions: Thoracic Outlet Syndrome

Treatments: Drug: Botulinum Toxin Type A; Other: Normal Saline injection

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT01405482

H11-00407

Details and patient eligibility

About

Botulinum toxin type A injected into the anterior and middle scalene muscles will reduce the irritation on the neurovascular structures at the interscalene triangle in subjects with TOS. This will lead to reductions in pain and paresthesias, and improvements in function when compared with injection of placebo.

Full description

To assess the effect of Botulinum Toxin Type A (BTX-A) injections into the scalene muscles on pain, paresthesias and function in subjects with TOS.

Hypothesis:

BTX-A injected into the anterior and middle scalene muscles will reduce the irritation on the neurovascular structures at the interscalene triangle in subjects with TOS. This will lead to reductions in pain and paresthesias, and improvements in function when compared with injection of placebo.

Study design:

Double-blind, randomized, placebo-controlled parallel groups effectiveness trial evaluating changes in pain, paresthesias and function before, at six weeks and four months following injection.

Study population:

Sixty subjects at least eighteen years of age with a clinical diagnosis of TOS of at least three months duration but less than one year, referred to our practice for management of TOS.

Intervention:

Each subject will receive an injection under EMG guidance into the anterior and middle scalene muscles of either 100 units of BTX-A (experimental group), or normal saline (control group). Outcome measures:

The primary outcome measure will be pain as measured on a ten point Numeric Rating Scale with a two point reduction considered significant. Secondary outcomes will be paresthesias as measured on a Numeric Rating Scale, function measured on the Disabilities of the arm, shoulder and hand (DASH) questionnaire.

Enrollment: 60 estimated patients

Sex: All

Ages: 19+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age at least 19 years
• Medically stable
• Able to give informed consent
• Meets criteria for clinical diagnosis of TOS
• Symptoms of TOS present for at least three months and less than two year
• Have had EMG studies and a CT or MRI scan of the cervical spine

Exclusion criteria

• Prior treatment with BTX-A
• Allergy to BTX-A
• History of botulinum toxicity
• Prior scalenectomy
• Surgery for TOS planned within four months
• Use of blood thinners, i.e., warfarin; unfractionated or low molecular weight heparin
• History of Myasthenia Gravis, Eaton-Lambert Syndrome or Shy-Drager Syndrome
• Unable to complete follow-up assessments at 6 weeks and 4 months
• Any abnormalities on EMG, CT or MRI studies suggesting an alternate diagnosis
• Pregnancy or planned pregnancy within six months

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

---

60 participants in 2 patient groups, including a placebo group

Botulinum Toxin Type A injection

Active Comparator group

Description:

Double-blind, randomized, placebo-controlled trial evaluating changes in pain, paresthesias, and function in subjects with TOS before, at six weeks, and four months following injection of BTX-A into the scalene muscles and pectoralis minor muscle under EMG guidance.

Treatment:

Drug: Botulinum Toxin Type A

Normal Saline

Placebo Comparator group

Description:

Double-blind, randomized, placebo-controlled trial evaluating changes in pain, paresthesias, and function in subjects with TOS before, at six weeks, and four months following injection of placebo into the scalene muscles under EMG guidance.

Treatment:

Other: Normal Saline injection