title: Correlation of botulinum toxin dose with neurophysiological parameters of efficacy and safety in the glabellar muscles: a double-blind, placebo-controlled, randomized study.
abstract: Despite the extensive use of botulinum toxin type A (BoNT-A) in treatments for glabellar frown lines, the dose-response effect in the glabellar muscles remains unknown. The aim of this randomized, double-blind, placebo-controlled prospective study was to characterize the neurophysiological parameters that correlate with the effect of BoNT-A in the glabellar muscles and its diffusion to surrounding ocular muscles. Sixteen healthy women were recruited and randomized to 3 different dose-groups of onabotulinumtoxin A (Vistabel®) or placebo and followed 24 weeks by neuro-physiological examinations. Efficacy of treatment on corrugator supercilii muscles was measured by compound motor action potential (CMAP) and electromyography (EMG). Photographs were used to score glabellar frown lines. Diffusion of the drug to surrounding muscles was assessed by CMAP of the nasalis muscle, EMG and concentric needle electrode jitter analysis (CNE) of the orbicularis oculi muscle. CMAP reduction correlated well with intramuscular BoNT-A dose. Muscle paralysis, measured by EMG, began from 2 weeks and was not entirely reversed at 24 weeks in individuals who received high dose of onabotulinumtoxin. Limited diffusion of orbicularis oculi was detected with CNE. In conclusion, we developed a novel neurophysiological strategy for effect evaluation of BoNT-A in glabellar muscles. CMAP and EMG correlated with given BoNT-A dose and are more defined effect measures than clinical glabellar photo scales.
authors: Department of Medical Sciences, Uppsala University, SE-753 85 Uppsala, Sweden. mohammad.alimohammadi@medsci.uu.se.
authors: Mohammad
authors: M
authors: Alimohammadi
authors: Mats
authors: M
authors: Andersson
authors: Anna Rostedt
authors: AR
authors: Punga
mesh_terms: D000200:Action Potentials; D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000009:adverse effects; D003357:Cosmetic Techniques; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004576:Electromyography; D005152:Facial Muscles / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D009799:Ocular Physiological Phenomena / Q000187:drug effects; D010781:Photography; D011446:Prospective Studies; D015595:Skin Aging / Q000187:drug effects
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A