Small Fiber Neuropathy-caused by Lumbar nerve damage?
 

I have Idiopathic Small Fiber Neuropathy confirmed May 2012 by skin biopsy.
I had a Foraminotomy in 2007 because of Sciatica pain in my right leg, shortly thereafter I had numbness and needle pricks in my right thigh, the Neurological surgeon said it would go away in the near future, yeah right!
In March, this year, after severe Sciatica nerve pain I had L3, L4, L5 fused by a Orthopedic Surgeon. Shortly thereafter I had numbness and needle pricks in both legs and burning feet.
The Neurologist I am now seeing said he doubted the SFN could be caused by damage to the Lumbar nerve. He told me to buy Metanx and come back in 2 months, the Metanx has done nothing, nor did Gabapentin.
Since he has not found the cause of the SFN I can only guess it is most likely nerve damage or nerve compression in the Lumbar region.
Are there any tests that I can politely suggest to him that will confirm or reject my opinion?

It would be unusual--
 

--to have an isolated small-fiber syndrome just from lumbar compression/radiculopathy; in such cases one usually has evidence of larger, myelinated nerves having been damaged as well. Have you had a full lower extremity nerve conduction/EMG series done, including the paraspinal muscles of the lower back, to try and see if there is signal disruption there?

None of us are excused from being "co-morbid"--one can have lumbar or sacral compression and have other things going on as well. In fact, there is something called the "double crush hypothesis", which theorizes that nerves already damaged by some process can get mechanically compressed and produce symptoms greater than one would suspect from "the sum of the parts".

As far as testing, have you seen the LizaJane spreadsheets at lizajane.org? These were designed to be about as comprehensive a series of possible tests for neurological symptoms as some very wide-ranging minds could come up with; you might want to take a look and see what you've already had, and not had.

lumbar spine compression
 

Hello, I read your email with interest. I have also been diagnosed with idiopathic small fiber neuropathy mostly in my pelvis and lower extremities. I have had ever test available it seems. Skin biopsy with positive for SFN. The only evidence of disease is nerve compression at L5S1. My back does hurt but my pelvis feels like its on fire most of the time especially after defecating. I am on Lyrica which helps a bit. I bought a teeter board and that helps more. My doctors say the compression cannot cause the SFN but I don't believe them. If not, what else? Any thoughts?

I have nothing to base this on besides just how my body/back feels and some circumstances the preceded the onset of my idiopathic SFN, but I've come to suspect that the cause of my problems is spinal. I say this even though MRIs performed on my entire spine show no cause.

While doing some research, I came across this interesting article that came from Georgetown Univ. Medical Center:

http://www.asra.com/display_fall_2011.php?id=74

Janie

I'm curious, is there any involvement with hands and arms? I guess it is just lower torso, if you think it is from a lumbar vertebra. My Lumbar vertibra mainly L1 is kind of munched on my x-ray, so I was thinking it might have something to do with my PN, but I also have hand and arm pain, and sometimes upper back and neck. Maybe if there was a compression of the spinal cord in the neck, it would create these symptoms of whole body SFN...
You have to keep in mind, like the journal says, they are surmising that there is a connection to diabetes, etc. my neurologist was trying to cram me into this catagory, even though I didn't have diabetes 30 years ago... Maybe it makes rm feel better to lump everyone into one group? Either that, they just label it ideopathic and move on...

My legs bear the brunt of my symptoms, but I do feel it everywhere. When I wake up in the morning, my legs feel the best they will all day, but body-wide I kind of feel like I have a finger in a low voltage electrical socket. I usually wake up on my back, and if I just roll on my side, it subsides. Is that a clue?

My problems actually started in my left leg about 30 years ago, but were stable until last year. Coincidentally or not, I also developed neck problems 30 years ago. I did a "planking challenge" last October and did something to my neck that made it lose mobility like it was stuck. It resolved after a few days, but the SFN hit me all over two weeks later.

Because MRIs show nothing, all docs proclaim my problems are not spinal. I did, however, have two months of PT on my neck because the neuro said I had obviously problems there, but it didn't help the SFN at all.

Taking R-Lipoic Acid supplements may be what has helped lessen the symptoms somewhat. I'm not as bad as I was 3 months ago, but I've been dealing with this for 11 months now.