A study conducted at the University of Calgary, Faculty of Kinesiology, and published on the Journal of Biomechanic’s Web site, www.jbiomech.com, reports that botulinum toxin Type A passes easily to surrounding muscles and is more difficult to control once injected than many people suspect.
"The injection doses used in this study are similar to those used in human injection protocols for the soleus muscle, both for spastic cerebral palsy in children and hemi-plegic adults secondary to stroke," says Walter Herzog, PhD, who led the study.
Herzog’s lab was trying to use the product in ongoing research that examines how muscle weakness contributes to joint degeneration. The idea was to use botulinum toxin Type A as an agent to temporarily paralyze muscles. What they found is that the toxin they used passed easily into the surrounding muscles and weakened all the muscles in the area.
"The main reason that this is significant," says Herzog, "is that many people believe that when Botox is injected into a single muscle it stays there. This research shows that it is not that easy to control. As therapeutic applications of BTX-A in humans increase, it is important that we understand more about the functional affects of this product which, at the end of the day, is a toxin."
[www.medicalnewstoday.com, February 27, 2008]