title: Single CT-guided chemodenervation of the anterior scalene muscle with botulinum toxin for neurogenic thoracic outlet syndrome.
abstract: OBJECTIVE
  To examine pain relief in patients with neurogenic thoracic outlet syndrome (NTOS) after a single, low dose injection of botulinum toxin A (Botox) into the anterior scalene muscle (ASM) under computed tomographic (CT) guidance.
  
  
  METHODS
  Prospective longitudinal study.
  
  
  METHODS
  Academic medical institution.
  
  
  METHODS
  Patients 18 years of age and older were evaluated for potential scalenectomy and first rib resection using the transaxillary approach at the study institution between 2005 and 2008. All patients had failed physical therapy. A total of 29 procedures on 27 participants were studied.
  
  
  METHODS
  A single, 20-unit injection of Botox into the ASM under CT-guidance.
  
  
  METHODS
  Short-form McGill Pain Questionnaire (SF-MPQ) prior to and at 1, 2, and 3 months post-Botox toxin injection.
  
  
  RESULTS
  There was a decline in pain during the 3 months subsequent to Botox injection as noted by the following components of the SF-MPQ: sensory (P = 0.02), total (P = 0.05), visual analog scale (VAS [P = 0.04]), and present pain intensity (PPI) score (P = 0.06). The proportion of patients reporting more intense pain scores did not return to the pre-intervention level at 3 months post-Botox injection.
  
  
  CONCLUSIONS
  Patients experienced substantial pain relief in months 1 and 2 following a single Botox injection into the ASM under CT guidance. Significant pain reduction was noted for 3 months after Botox injection with respect to both sensory and VAS scores, and the total and PPI scores approximated statistical significance. After 3 months, patients experienced a 29% decrease in the sensory component of their pain as well as an approximate 15% reduction in their VAS score. A single, CT-guided Botox injection into the ASM may offer an effective, minimally invasive treatment for NTOS.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Division of Pain Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. pchristo@jhmi.edu
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Christo
authors.forename: Dana K
authors.initials: DK
authors.lastname: Christo
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Carinci
authors.forename: Julie A
authors.initials: JA
authors.lastname: Freischlag
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009121:Muscle Denervation / Q000379:methods*; D018482:Muscle, Skeletal / Q000294:innervation* / Q000601:surgery*; D009498:Neurotoxins / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy / Q000601:surgery; D010147:Pain Measurement; D011446:Prospective Studies; D013901:Thoracic Outlet Syndrome / Q000188:drug therapy* / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D009498:Neurotoxins; D019274:Botulinum Toxins, Type A