title: Intramuscular botulinum toxin in complex regional pain syndrome: case series and literature review.
abstract: BACKGROUND
  Pain associated with Complex Regional Pain Syndrome (CRPS) is frequently excruciating and intractable. The use of botulinum toxin for relief of CRPS-associated pain has not been well described.
  
  
  OBJECTIVE
  To assess whether intramuscular botulinum toxin injections cause relief of pain caused by CRPS, and to assess the risks of this treatment.
  
  
  METHODS
  Retrospective chart review.
  
  
  METHODS
  Outpatient clinic.
  
  
  METHODS
  37 patients with spasm/dystonia in the neck and/or upper limb girdle muscles.
  
  
  METHODS
  EMG-guided injection of Botulinum Toxin - A (BtxA), 10-20 units per muscle. Total dose used was 100 units in each patient. Local pain score was measured on an 11-point Likert scale, 4 weeks after BtxA injections.
  
  
  RESULTS
  Mean pain score decreased by 43% (8.2 ± 0.8 to 4.5 ± 1.1, P < 0.001). 97% patients had significant pain relief. One patient had transient neck drop after the injections.
  
  
  CONCLUSIONS
  This is a retrospective study, it lacks a control group and hence the placebo effect cannot be eliminated. This study does not provide information on the efficacy of this treatment after 4 weeks.
  
  
  CONCLUSIONS
  Intramuscular injection of botulinum toxin in the upper limb girdle muscles was beneficial for short term relief of pain caused by CRPS. The incidence of complications was low (2.7%).
authors.affiliation: Hahnemann University Hospital, Philadelphia, PA and Department of Neurology, Drexel University College of Medicine, Philadelphia, PA 19107, USA.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Kharkar
authors.forename: Prakash
authors.initials: P
authors.lastname: Ambady
authors.forename: Yedatore
authors.initials: Y
authors.lastname: Venkatesh
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Schwartzman
mesh_terms: D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D020918:Complex Regional Pain Syndromes / Q000145:classification / Q000188:drug therapy*; D004576:Electromyography; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D016013:Likelihood Functions; D008297:Male; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D010147:Pain Measurement; D010446:Peptide Fragments / Q000627:therapeutic use*; D012189:Retrospective Studies
chemical_list: D009465:Neuromuscular Agents; D010446:Peptide Fragments; C505468:botulinum neurotoxin A (870-1295); D019274:Botulinum Toxins, Type A