Accuracy of punch skin biopsy for nervedensity
 

Hi. I hope someone can comment/inform regarding this topic.
Here is my situation: Over 1 year ago my local neurologist referred me to a large University center to se a professor specialicing in neuropathy.
( my local neuro is actualy my neurovascular neuro)

This specialist saw me, did thorough physical neurological exam, and did EMG and NCS which he all performed himself.
Result Peripheral sensorymotor axonal polyneuropathy. Also evidence of small sensory nerve fiber dysfunction predominently affecting sympathetic components.
"To evaluate the small the small sensory fibers (autonomic nerves) sympathetic skin responses were obtained from feet."

I have asked this doctor to do a skin biopsy, but he has declined, saying," I do not need to do that, I have tested, I know you have small fiber neuropathy But if the local doctor will, they can easily do it there.

So, my local neuro, who referred me to the specialist, has been saying," If you have neuropathy, you should not have this brisk reflexes"
( I will need to bring in some information to the doctor. He obviously does not know that with SFN, one can have much of negative, normal assessment., EMG NCS included)

So the story goes, that recently our local neuro group has hired a new neuromuscular doctor that has done this skin test in the past, even though the office has never.
Well, he ordered the test, and I had it. Carefully documented and sent to Neuropath lab.

Result negative for SFN.

I have had such terrible painful symptoms with burning and all sorts of perasthesia.actually so bad that I almost mistook the symptoms for TIA a couple of times with really numbness in arm

Question:
How often are theese tests wrong?

Can they be repeated? ( Insurance company willing)

I have been so sick with this neuropathy in addition to newly diagnosed Rheumatoid Arthritis, that my rheumatologist has recomended to treat me with Rituxan.

No, We will have to make sure we get some objective documentation regarding the SFN.

Any suggestions?

This paper says a accuracy of 88.4 % http://www.therapath.com/ENFD.php
The other option the Doctor can opt for, is getting a sweat gland test.
http://www.therapath.com/Sweat_Gland...er_Density.php
Hope this helps.
Jon

So did your EMG/NCS show long fiber damage to reach that diagnosis? My neuro told me that if someone has long fiber damage the likelihood is they have some small fiber involvement as well. Will a second biopsy change your course of treatment?

As far as reflexes go, brisk reflexes are common at first with neuropathy in the lower extremities. As the condition progresses they usually diminish.

I've written about this a lot in the past.
 

Very busy right now (it's heavy test prep season), but take a look at:

http://neurotalk.psychcentral.com/sh...61#post1052061

There are other threads in which I have addressed how "normal" values are determined in skin biopsy and how they can be misleading, but this is the most recent.

reply
 

did you see your report ? my punch test was so vague said not present but... there was a comment on the nerve fibers it did not really make a lot of sense so if you did not see and read the report I would get a hold of it

Hey Synnove,

I had the same issue a couple of years ago where the biopsy came back negative from Therapath. A year later they compared a new punch biopsy with the previous year and determined that I had diminished sweat glands and said the I have autoimmune SFPN.
What scares me the most is that the neuropathy may be progressing quickly if the test two years ago did not show anything and now the new test shows diminished sweat glands.

N1