title: Comparison of botulinum toxin serotypes A and B for the treatment of cervical dystonia.
abstract: OBJECTIVE
  To directly compare two serotypes of botulinum toxin (BoNTA and BoNTB) in cervical dystonia (CD) using a randomized, double-blind, parallel-arm study design.
  
  
  METHODS
  Subjects with CD who had a previous response from BoNTA were randomly assigned to BoNTA or BoNTB and evaluated in a blinded fashion at baseline, 4 weeks, 8 weeks, and 2-week intervals thereafter until loss of 80% of clinical effect or completion of 20 weeks of observation. CD severity was measured with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), and adverse events were assessed by structured interview. Statistical analysis included Wilcoxon rank sum test, log rank tests, and Kaplan-Meier survival curves for duration of effect.
  
  
  RESULTS
  A total of 139 subjects (BoNTA, n = 74; BoNTB, n = 65) were randomized at 19 study sites. Improvement in TWSTRS score was found at 4 weeks after injection and did not differ between serotypes. Dysphagia and dry mouth were more frequent with BoNTB (dysphagia: BoNTA 19% vs BoNTB 48%, p = 0.0005; dry mouth (BoNTA 41% vs BoNTB 80%, p < 0.0001). In clinical responders, BoNT A had a modestly longer duration of benefit (BoNTA 14 weeks, BoNTB 12.1 weeks, p = 0.033).
  
  
  CONCLUSIONS
  Both serotypes of botulinum toxin (BoNTA and BoNTB) had equivalent benefit in subjects with cervical dystonia at 4 weeks. BoNTA had fewer adverse events and a marginally longer duration of effect in subjects showing a clinical response.
authors.affiliation: Rush University Medical Center, Chicago, IL 60612, USA. ccomella@rush.edu
authors.forename: C L
authors.initials: CL
authors.lastname: Comella
authors.forename: J
authors.initials: J
authors.lastname: Jankovic
authors.forename: K M
authors.initials: KM
authors.lastname: Shannon
authors.forename: J
authors.initials: J
authors.lastname: Tsui
authors.forename: M
authors.initials: M
authors.lastname: Swenson
authors.forename: S
authors.initials: S
authors.lastname: Leurgans
authors.forename: W
authors.initials: W
authors.lastname: Fan
mesh_terms: D000328:Adult; D000368:Aged; D001905:Botulinum Toxins / Q000008:administration & dosage* / Q000009:adverse effects; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000009:adverse effects; D003680:Deglutition Disorders / Q000139:chemically induced; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000139:chemically induced / Q000503:physiopathology; D009334:Neck Muscles / Q000187:drug effects* / Q000294:innervation / Q000503:physiopathology; D013995:Time; D013997:Time Factors; D014103:Torticollis / Q000188:drug therapy* / Q000503:physiopathology; D016896:Treatment Outcome; D014987:Xerostomia / Q000139:chemically induced
chemical_list: C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A