Mat,

There are several posters that report pain subsiding and numbness taking over. I agree with Glenn, that it can be a sign of severe damage or dying of the nerves. This needs to be reported to your neurologist at the end of the month and a new skin biopsy taken or follow-up NCS. If there nerves are this damaged, then something would show on biopsy.

I think it's times for a full autonomic battery to be done including tilt table, echo, holter, 24 hour BP, QSART, etc. They need to get to the bottom of this for you.