It is a form of botulism. My son in 5 and has spastic diplegia cp. He does real well for about 3-5 months following the injections. This producing better overall balance. The effects are short term but the benefits are long term.
Strength is built and retained after the effects of the botox are gone.
Usually additional injections are given to further increase strength and range of motion. We are awaiting scheduling for his second round of injections. I've heard various stories about the actual time of injection. A cream is applied 2 hrs before the injection which numbs the area completely. So in other words it was virtually painless.