Correlation of botulinum toxin dose with neurophysiological parameters of
efficacy and safety in the glabellar muscles: a double-blind, placebo-controlled,
randomized study.
Author(s): Alimohammadi M(1), Andersson M, Punga AR.
Affiliation(s): Author information:
(1)Department of Medical Sciences, Uppsala University, SE-753 85 Uppsala, Sweden.
mohammad.alimohammadi@medsci.uu.se.
Publication date & source: 2014, Acta Derm Venereol. , 94(1):32-7
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.
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