[boiler1993]

Hi,

I have posted before about my symptoms of heart racing, painful sensations in my legs and arms (and sometimes trunk) (especially in the heat), and a few others (these are the main ones). Anyway I had a skin biopsy done and here were my results:

ENFD
Thigh -9.7 (cutoff 5% = 6.8 at thigh, 10% = 8)
Calf - 8 (cutoff 5% = 5.4, 10% = 5.7)

SGNFD
Thigh - 29.2 (below 5th % - cutoff = 37.8 )
Calf - 44.5 (cutoff 5% = 36.5)

I know the other values are considered normal but I have a few concerns:

1. I am only 19 and they said in the report that they dont have data for someone of my age but that my densties should be higher.

2. What percentile would these probably be considered? Are they still low?

3. The thigh is more reduced for its percentile than the calf and the report said "a greater reduction of the ENFD at the thigh than claf may indicate the presence of a multifocal sensory neuropathy or sensory neuronopathy" thoughts?

4. Any idea what percentile the calf SGNFD is?

THANK YOU SO MUCH!

[glenntaj]

--but that is not a very helpful criterion in these cases, as we don't know what your nerve fiber densities were you had symptoms--in other words, there is no 'normal, healthy baseline' to compare these to.

This is one of the big problems with the rather arbitrary cut-off of below 5th percentile and above 95th percentile for diagnosis of small-fiber neuropathy (I've written about this a number of times here); it's also why they are supposed to report the condition of the fibers they see under electron microscopy.

And, yes, the normed standards that originally came from Johns Hopkins were for the most part determined from people older than you, so that is another interpretive problem. It is know that normal nerve fiber density does decrease with age in general, but there is great individual variation.

It is interesting, though that the sweat gland nerve fiber density was apparently of lower percentile (if I'm reading this correctly). Small, unmyelinated fibers in the skin subsume the sensations of pain and temperature, but they also control the expression of many autonomic functions, such as sweating and blood pressure. These results would be consistent with some degree of small-fiber autonomic neuropathy.

Take a look at:

https://www.therapath.com/ENFD.php

[boiler1993]

On the website it says : "in sensory neuronopathies or multifocal neuropathies, it (ENFD) may be preferentially reduced proximally at the thigh ". Does this match my results (the thigh number is higher but more reduced based on the norms). Also I sent some questions to the lab about y age and the affects on the results including a question about the morphology of the fibers because it was not included in teh report.

Glenntaj - you said that my values were still low...do you have any idea what a normal range for these areas (thigh and calf) are? also when you say that the SGNFD could "indicate small-fiber autonomic neuropathy" do you think that it could also indicate purely SFN?
thank you so much

[mg neck prob]

[Boiler Im sorry I havent got back with you--- I know Glenn is much more versed then me ---all i know I was postive and since that time I have had -- my neck and cancer-- this issues took a back seat and so did my memory(lol) about what the % mean. I hope Glenn or someone here can get you the info u need . I tried to find my orginal path report this weekend so far cant locate it to compare.

[boiler1993]

mg - any thoughts on the numbers?

[mg neck prob]

Originally Posted by boiler1993

mg - any thoughts on the numbers?

Here is just my thought and I could be wrong but I have a little more background of you-- then others -- now your qsart test for sweat came back abnormal and with your previous symptoms like heart racing and you rest pulse being high to me indicates a form of neuropathy even if its not sfn its does seem automonic neuropathy ---example damage to the nerve that supply the blood would effect blood pressure and body temp...i forgot does ur blood pressure change via sitting or standing?--- I also remember u had a problem at movies --with your resting heart rate 2. I know u execise do u get any unusal shortness of breath when you do ? You heart rythms can be faster or slower with this too. Hopefully --Glenn chimes into to help me here a bit. Have u been lossing any weight without trying. What does you DR say??

[boiler1993]

mg/glen - I am not sure about blood pressure change upon standing - i havent had autonomic testing. No I dont get any shortness of breath when exercising and I am not sure about heart patterns but when I have taken heart rate it is about the same as everyone else (i am on a team). And no i havent been losing weight. My dr is supposed to call sometime...they gave him my free times through thurs so I should have talked to him by then. Could autonomic problems be causig the sensory pain? (it does happen when I am hot but i didnt think that was an autonomic symptom). thanks

[glenntaj]

Many neuropathies, but not all, are "length dependent"--that is, the damage or "die-back" starts first at the nerve endings that are farthest from the seat of circulation and then progressively (though often slowly) continue towards more proximal regions of the body (as opposed to "distal", which describes toes, feet, fingertips). Part of the reason that the skin biopsies are taken from near the foot and the thigh is to see if this common distal/proximal gradient is going on (it is very common in toxic, metabolic, an ischemic--processes that damage blood vessels--neuropathies).

You don't seem to have this, though, which is why neuronopathy was mentioned. This is slightly different, and not length dependent, as the damage seems to occur in the dorsal root ganglia--at the level of the cell body, not the axonal (fiber) endings. There are a number of different processes that can result in a neuronopathy, many of them autoimmune, though there are many idiopathic cases as well:

http://neuromuscular.wustl.edu/antibody/sneuron.html

These are primarily sensory, though some of the conditions that come with them have autonomic components as well, as small fibers do control autonomic functions.

By the way, here are the figures from my skin biopsy reports regarding the McArthur protocol norm determinations for nerve fiber density at calf and thigh:

Mean: +/- 1 standard deviation: Range: 5th percentile:

21.1 +/-10.4 2.9--57.5 5.2 (Thigh)

13.8 +/-5.6 0.6--32.2 3.8 (Leg)

These figures are expressed as number of distinct fibers per millimeter of skin, and are normed for males 40-49 (which I was at the time); I'll research it by I believe the figures for younger males are a bit higher, but not much.

My initial report not only showed figures below the fifth percentile, but also noted "excessive branching and swelling, consistent with a small fiber neuropathy". I did not have any autonomic symptoms--just very severe small fiber nerve pain body-wide (that came on acutely--in hours). My last biopsy--the good thing about them is they can be done repeatedly for comparison--showed me up to about 16th and 18th percentile at leg and thigh, respectively--I have gotten re-enervation and this corresponds to the reduction of symptoms. (I'm due for another one soon.) However, the problem is we have no idea how this compared to my nerve fiber density before my acute onset on April 11 2003.

Many small fiber neuropathies do have some autonomic involvement as part of the package, although sensory nerves may be affected more than autonomic ones (and vice versa); often the autonomic effect is slight or "sub-clinical" and only noticed with very exact measurements/testing:

http://neuromuscular.wustl.edu/sensory-small.html

http://neuromuscular.wustl.edu/senso...tml#idiopathic

I suspect you are experiencing some sort of small-fiber syndromes with both sensory and autonomic features, and it may not be length-dependent. But as you can see, this is not uncommon, unfortunately.

[boiler1993]

Glen- just so you know (if you are able to find nerve data) I am 19 years old and female. Also maybe I am misreading this data but if the means are 21.1 and 13.8 AND my values fall outsied of one standard deviation...isnt this considered low (even though I am above the 5th percentile)? I mean my values are significantly lower than the mean of both...and according to therapath, if anything my value norms should be higher...wow there are lot of things which can cause these symptoms this one caught my eye though " Sensory Neuronopathy: Small fiber" because it is like the first one that includes my age in onset range.. any way thank you again hopefully i will hear from my doc or/and the lab today

[glenntaj]

--the values are certainly below the means, but the fluctuations are so wide that when the McArthur protocols were established I do think they erred on the side of underdiagnosing, it choosing 5th and 95th percentile cutoffs as incontrovertible evidence of small fiber damage.


I haven't seen much distinction in the studies as regards males/females--the original enumeration of 'normal' subjects included both in roughly equal numbers.

The search for a cause of this may be long and expensive--and a lot of these small fiber syndromes remain stubbornly idiopathic. Often, toxic, autoimmune, or glucose dysregulation mechanisms are considered possible etiologies, but are hard to prove.

What other kinds of testing have you had? And have you seen the Liza Jane spreadsheets (which were developed to be about as comprehensive a lists of tests for neurological symptoms that the good minds here could think of)?--

www.lizajane.org