You can have small fibre peripheral neuropathy as a direct result of CRPS.

CRPS can, through mechanisms that are not definitively known or understood, reduce the density of small nerve fibres. These are seen when punch biopsies are taken and examined. This means that CRPS is also regarded as a form of peripheral neuropathy. Most people won't know what damage, if any, has been done to their small nerve fibres because most people don't get punch biopsies as part of the diagnostic process.

The realty is that most people diagnosed with CRPS are able to be comprehensively diagnosed without the need for such a biopsy so the true numbers of people exhibiting this clinical sign are not known. Punch biopsies are regarded as invasive treatment so, like all invasive treatments, are not recommended for anyone with a diagnosis of CRPS. Except, of course, invasive processes that need to be done in an emergency. There is a risk of increased severity of existing CRPS symptoms, healing issues and the procedure itself could trigger excessive pain.

The SGB will not definitively confirm or reject a diagnosis of CRPS. It is just another diagnostic tool that is used to try and build a picture. The results (which can be a mixture of subjective and objective) will be considered by the physician along with all of the other information he has and the current, diagnostic guidelines for CRPS will be applied to reach an opinion on your case.

You could have a small fibre neuropathy without CRPS and you could have CRPS without small fibre neuropathy. Or you could have both! Simple huh?!!! Its best to go through the testing, do your own research from good, reputable sources like the RSDSA.org website resources and see what the doctor says. At least if you have done your own research, you will be informed enough to understand what you are being told and to ask probing questions. I think you probably just have to wait a bit longer as your doctor amasses the information but realise that no one test is going to give you a definitive answer where CRPS is concerned.