Hi

As far as I understand it (I haven't had one myself, and I'm sure others will know more ) it's not unusual to experience only a short period of relief from a first block. I think they work best in a series of them over the course of several weeks.

I think the main purpose of them is as a diagnostic tool. If your symptoms are relieved by the block, then it shows that your pain is sympathetically maintained, and therefore still might have a chance of being successfully treated by a series of blocks. If the block hadn't done anything, then it would show that your pain was no longer sympathetically maintained, and therefore you wouldn't benefit from blocks as a treatment.

Hope I've got this right! I'm sure someone will be along soon who knows about this in more detail

In the meantime, take care and do some reading about it online. Try RSDSA.org and similar sites with some sense lol.

Hope you have a good night.

Bram.