My son, a quadriplegic of a little less than 3 yrs, has severe spasms-regularly.
He opted to take the botox shots to try to relieve them.
He turned out to be in the 10% who are adversely affected and was severely incapacitated and lost the progress he had been making for almost 2 yrs. He lost over a year's worth of hard work in PT & OT to get him semi-independent. He thught a 90%/10% shot was worth the risk, but wound up behind the 8 ball in the 10%.
Be sure you know the negatives before you have this procedure done.