title: Regional diffusion of botulinum toxin in facial muscles: a randomised double-blind study and a consideration for clinical studies with split-face design.
abstract: Despite the extensive use of botulinum toxin A (BoNTA) in medical and cosmetic treatments, the potential spreading of BoNTA to surrounding tissues remains unknown. A patient with hemifacial paralysis upon blepharospasm treatment with low dose of BoNTA, prompted us to investigate the spreading effect. A randomised, double-blind study was conducted in which 5 healthy women (33-52 years) were treated with different doses of onabotulinum toxin unilaterally in the corrugator muscle. Parameters of efficacy and diffusion (CMAP; EMG and jitter analysis) in both glabellar and frontalis muscles were assessed at baseline, 2 and 4 weeks following BoNTA injection. CMAP of the treated glabellar muscles was reduced to approximately 40% in all dose groups. Additionally, contralateral CMAP reduction was observed in 3 of 5 subjects. These data confirm regional diffusion of BoNTA in facial muscle application, which raises question on the reliability of split-face models in BoNTA studies.
authors.affiliation: Department of Clinical Neurophysiology, Uppsala University, Uppsala, Sweden.
authors.forename: Anna Rostedt
authors.initials: AR
authors.lastname: Punga
authors.forename: Annika
authors.initials: A
authors.lastname: Eriksson
authors.forename: Mohammad
authors.initials: M
authors.lastname: Alimohammadi
mesh_terms: D065087:Acetylcholine Release Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D000200:Action Potentials / Q000187:drug effects; D000328:Adult; D000369:Aged, 80 and over; D001764:Blepharospasm / Q000188:drug therapy; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D018849:Controlled Clinical Trials as Topic / Q000379:methods; D004058:Diffusion; D004311:Double-Blind Method; D004576:Electromyography; D005152:Facial Muscles / Q000187:drug effects / Q000378:metabolism*; D005158:Facial Paralysis / Q000139:chemically induced; D005260:Female; D005546:Forehead; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012107:Research Design
chemical_list: D065087:Acetylcholine Release Inhibitors; D019274:Botulinum Toxins, Type A