--for a skin biopsy to test for small-fiber neuropathy to be done only on the upper extremity, as the majority of small-fiber neuropathy cases are length-dependent--that is, the longer nerve fibers in the legs and feet are affected first. Usually, samples are taken from just above the ankle and the mid-thigh, and also sometimes from the back of the elbow and the gradients compared. If there is also NOT a length-dependent gradient, that also has implications for diagnosis. But the comparisons should be done, as it is possible to have "local", non-systemic nerve damage/axon loss, often from injury, and that would likely show on a skin biopsy as damage to one area but not another. For instance, axon loss in the upper arm, but not in the thigh or calf, would be consistent with nerve injury to the brachial plexus or the cervical spine roots, and in the latter case most likely caused by either acute disc injury or more chronic neural formainal narrowing due to disc herniation/osteophytic bone spur overgrowth.

And, there's also the RSD history to complicate matters.

It would be wonderful if you could post the language used in the imaging reports--we do have people here well versed in that who could provide perspective.

Hi Catra...

I've been searching the connection between CRPS and SFN, and there seems to be one:

Skin biopsy in complex regional pain syndrome: case series and literature review. - PubMed - NCBI

and
Complex regional pain syndrome - Diagnostic workup

So I guess a question to your new neuro would be if your biopsy is a separate issue or connected to your RSD/CRPS.

Thank you for the links! Helpful as always.

Just one more way that RSD complicates my life...trying to sort all of this stuff out. Is it caused by the RSD? Is it caused by the trauma? Is it caused by the trauma worsening the RSD? Will there ever ACTUALLY be an answer to these things or will it all just be speculation? Nothing to do but keep moving forward and gather as much information as possible.

Thanks again!

Hi Catra...

I've been searching the connection between CRPS and SFN, and there seems to be one:

Skin biopsy in complex regional pain syndrome: case series and literature review. - PubMed - NCBI

and
Complex regional pain syndrome - Diagnostic workup

So I guess a question to your new neuro would be if your biopsy is a separate issue or connected to your RSD/CRPS.

Thank you so much for this information! I really know very little about small fiber neuropathy and unfortunately I suffer from problems with my concentration as a result of the RSD...making it very hard now to read through some of the information I CAN find. I will definitely be asking about this at my appointment. I did have trauma to my neck and back as the result of my fall...one metal bar I landed on was right behind my neck and the other just behind the shoulders. I don't have a copy of the reports...but I will see if I can get them so that I can share that information with everyone.