Please explain difference in NLDSFN & SFN
 

Can someone please explain to me the difference between non legnth dependant small fiber neuronopathy and small fiber neuropathy? If there is one.

Also, can a skin punch biopsy tell the difference or what type I have:confused:? I'm getting that done in the next few weeks.

I'm new to all this and am confused about the difference. I'm trying to figure out what I have...symptoms being all over body parasthesias, burning pain, from head to toe, sudden onset.

Thank you.

If you have all-over body symptoms--
 

--whatever you have is not length-dependent.

Length-dependent refers to those neuropathies, often ischemic (circulatory) or metabolic in nature, in which the longests nerves are compromised first, usually at the very ends. That is because in these neuropathies, the nerves "die-back"; that is, due to the body's inability to transport sufficient nutrients/oxygen to the very ends of the nerves (farthest from the body's circulatory center), and/or to transport metabolic wastes away from those areas, the nerves begin to show problems at their very tips first.

Small-fiber diabetic neuropathy is the classic type for this process, which is why diabetics tend to get nerve problems first in their toes, then their feet, then their fingertips, and so on--the "stocking and glove" distribution.

It is, of course, possible to have small-fiber neuropathy that is not length dependent, as well as large-fiber neuropathy that isn't. It very much depends on cause. A number of autoimmune and toxic conditions have effects that are more global.

Thank you.

So does that mean that its legnth dependant only if it effects the classic glove/socks areas, but if its all over the body, it is non legnth dependant?

Also, are there different areas of the nerve that are damaged with the NLD vs. the legnth dependant?

This link is a very comprehensive explanation of Neuropathies, with definitions, etc. It has nice tables and lists too.
"An Approach to the Evaluation of Peripheral Neuropathies"

Mark B. Bromberg, MD, PhD

http://www.medscape.com/viewarticle/510706

If you do not have a membership, it is free to join, and a wonderful resource. I've had my membership for almost 10 yrs now.

Basically, that's correct--
 

--though there is some overlap, in the sense that a length dependent neuropathy may progress to many areas of the body over time.

The distinction of length/non-length dependent may mean little to the patient suffering from symptoms--it's more interesting from a clinical standpoint in determining process and onset.

peripheral neuropathy
 

I would like to know how your skin punch biopsey works.I to have an onset of burning pain from head to toe.Also pain in my knee joints.Doc says there is no cure.I am on Neurontin and Elevil[amytripline]

In a skin punch biopsy, a small skin sample about 1/4-inch (3mm) wide is taken by a special tool. It is spring loaded and goes down, takes a sample from your skin and pop backs up leaving a small hole where it took the sample. I doesn't really hurt and your wound repairs in about a week.

Typically, to test for non-length dependent SFN, a biopsy is taken from your ankle or foot and compared to a biopsy taken from your thigh. Under a microscope, the density of small nerve fibers is examined in each biopsy area. The results usually take about 2 weeks since the biopsied skin sample is sent to a lab for analysis.

If the sample taken from your upper leg shows fewer healthy nerve endings than the sample from your ankle, it is a confirmation of "non-length dependent small nerve fiber neuropathy/neuronopathy." So it can confirm a diagnosis if this result happens. However, sometimes a sample for a person with NLDSFN has the same number of healthy nerve fibers in both areas (falling into the normal range). In this case, only a "soft" diagnosis can be made based on patient reports of pain. For example, when pain is reported in the hip and thigh but not the feet, it is evidence for a diagnosis of NLDSFN.

In summary, a punch biopsy can, but doesn't always, confirm NLDSFN.

Hope this helps.