Dear Mrs.D,

Please bear with me, I just wanted to make sure my understanding on DRG is correct - damage on DRG does not reflect on skin biopsy? I want to tell this to my doctor in my next visit.

You know sometimes, when I read I understand the words (as individually written) but i could not somehow connect their meaning in the whole context of the idea

Thank you.

In humans so far we don't know the answer to this question.

But I did find a link to a study in animals suggesting that
dorsal root damage precedes sensory neuron death in the periphery.

http://www.ncbi.nlm.nih.gov/pubmed/21924225

Thank you very much Mrs.D!

--the original paper by Dr. Abhey Mogehkar of John's Hopkins on small-fiber neuropathy secondary to damage at the level of the dorsal root ganglia (which I haven't been able to find an active link to this morning, though I think I actually have a hard copy somewhere in my files) does mention that one of the distinguishing characteristics leading to suspicion of DRG involvement is when the skin biopsy results are NOT length-dependent.

Also, see this description from the Washington University neiromuscular website:

http://neuromuscular.wustl.edu/antib...uron.html#sfsn

When you say "NOT length dependent", does it actually mean that the result of the skin biopsy is normal? Sorry, just want to make sure that I understand it.

--the more likely possibility is that samples taken from all areas will show intraepidermal nerve fiber density reduction, and that there will not be a pattern of greater reduction in samples taken farther from the center of the body (such as at the ankle) vs. more proximal areas (thigh, upper arm).

In length-dependent neuropathies, it's the fibers that are farthest from the body that show damage first, and that show greater damage as time goes on. this is thought to be due to the fact that much of the damage, whether diabetic, toxic, autoimmune, etc., is thought to be primarily circulatory/ischemic in nature, in that damage to small blood vessels results in nerves not getting enough nutrients/oxygen and being unable to efficiently remove waste products, and the farther this is from the center of circulation, the more likely this is to occur--it takes efficient circulation to do this in tissue in the feet, for instance, where blood also has to fight gravity.

I encountered an article today about non–length-dependent small-fiber sensory neuropathy. I could not copy it in the Forum.

http://onlinelibrary.wiley.com/doi/1...mus.22255/full

The article says that patients with NLD-SFSN, often develop SFSN symptoms and signs in a patchy distribution. This can include the face, upper limbs, or trunk before the lower limbs, or the latter may be involved simultaneously. This pattern of distribution suggests that NLD-SFSN most likely represents a ganglionopathy.
Also, it says that non-length dependent neuropathy shows reduction of IENFD on the skin biopsy.

Now I wonder, if my normal skin biopsy would fall under the non-length?

Thank you Glenntaj.
My skin biopsy says normal epidermal nerve fiber density and appearance from both distal leg and proximal thigh. Though, there might be a possibility that my coondition is DRG, but I am still hoping its not so I am still trying to find rhyme and reason on it.

I had no idea PN could affect proprioception , this was the first neurological symptom I actually had some 8yrs before my pn became apparent, is that possible ?

m

Why not? If there's a tissue in the body, there's a few diseases to match! I sometimes have phantom vibrations and my neurologist suggested it could be due to proprioceptive nerves getting hit. (But I mostly have the tingling/numbness/pain/burning thing going on.)