Hi Phaedra,
It happens to me all the time. It is on my left side (my CRPS started in my left arm/shoulder and now full body). This issue drive me crazy with pain sometimes at other times just noticable. The only thing different with me is the bad headaches happen in the middle of my brain.
The pain starts by CRPS nerves kinda like swell and obstructs muscles. Of course I also have degerative cerebral atrophy.
I hope this won't lead into a stroke like me...
Be safe and good luck with that block. Hope you find relief...