I am new here, but I wish to extend congratulations on your pain free days, Dan. From the comments, it appears to have been a very long time for you.
It seems that you knew well the dangers going into this procedure, as you stated if it paralyzed or killed you, that you accepted that risk. I would assume you exhausted any other options before reaching this conclusion. I don't wish to sound like a nervous nancy, but I can't help to express the dangers of experimentation with botulinum toxin. I don't think it's a decision that should be made lightly. There is a high amount of risk associated with high doses of botulinum toxin. It does seem to migrate to other parts of the body and to the brain. Botulinum Toxin type A does not seem to be attributed to neuron death by itself, although it's blocking of neural activity can cause adverse effects, including death.
I understand completely the desire to stop at nothing to silence the beast. But I do feel that Botox should be regarded as one of the high-risk options and I would encourage anyone interested to do research and weigh the risk before proceeding. That of course should be said for any medication, food, or even lifestyle choice for that matter.