Blocks need to be treated with respect. The experience of the doc with RSD, the time he spends, the meds he uses--all make a difference. This is your spine we're talking about! But, it is an important tool as well.

For the OP, was this a stellate ganglion block? I had a radiofrequency neurotomy that was a described as a longer lasting, more intense block, and I had horrible side effects...

How bad is the swelling? The severity is key.

If he's suddenly able to move it after long disuse that could account for some swelling and that in turn could cause numbness. The twitching could be a result of the nerves finally getting messages after so long a period of dysfunction.

Get him in to the doc that performed the block asap. Get a second opinion if he doesn't relieve your concerns.

5 blocks, especially in a short amount of time, can cause scarring on the nerves. This maybe should be his last... But, they might be finally starting to have a positive cumulative effect...