Hello Memphis and Welcome to Neurotalk!
I'm sorry to hear about everything that your son is dealing with right now!

I hope you can find something soon to ease his spasms and pain and will keep you both in my thoughts!!
I also suffer from Myoclonic Spasms although mine are as a result of another condition (Complex Regional Pain Syndrome). My leg bounces in the air on it's own uncontrolably and can be very painful and embarrassing - especially when I am out in public and it starts happening as people often tend to stare at it.
Has your son tried any muscle relaxants or anything yet? I was put on quite a few muscle relaxants such as Baclofen, Diazepam, Kenadrin but haven't found anything that helps really at the moment.
Here is a video of the spasms I have in my leg:
http://www.youtube.com/watch?v=xIXakErNBpE
Take care and please send your son my best wishes. If you ever need anyone to talk to, please know that I am here for you because I understand some of what you are going through!!
Alison.