Hi.
I received a call from the doctor yesterday informing me that the result of my skin biopsy is negative. This makes me happy knowing that I dont have PN, but at the same time more confused and anxious.

Confused and anxious because I experienced (and still is) most of the symptoms of a peripheral neuropathy. In fact, this was my official diagnosis from my previous 2 neurologist until I was referred to this 3rd neurologist who did the skin biopsy. I have very painful (both) feet, tingling, prickly skin similar to being rubbed by a sandpaper. I used to experienced severe burning but that stopped since March 15.

My doctor is no longer keen to pursue any further investigation of my condition. When I asked what would be the next course of action, he simply said "lets wait and observe". I am hoping not to just wait and observe. With the negative result, I asked if I have PN, but he could not give me a straight answer.

If my doctor is correct, what other condition/s could I have?

I am really hoping that anyone can give me some thoughts about my condition.

Thank you.

Mary

one thing that you should do is get the exact results, the full report of your skin biopsy. what percentages and description of condition of nerves may help you now if they are borderline, or may help you down the road to compare where you are at now and where you are at then. sometimes tests come back negative that are borderline positive but you dont get that information unless you get a copy of the report for yourself.

Echoes long agoYes, I will get the result soon. Hopefully, within the week. I will post when I get it.

Did I get you right - if one is in the borderline of positive, this will reflect negative? How long should be the ideal next biopsy to reflect changes, if any?



Mrs D, regardless of the result of my test, I will continue the supplements I am currently taking now. Ddo you think this is the right thing to do?

Thank you both!!!

Glentaj is the person to ask about the skin biopsy. There are certain high and low percentiles that are considered abnormal. He knows much more than me about it, and would also better be able to tell you when you should do it again.
I do know on tests you can be trending towards abnormal but still be in normal range for that test. For example i was usually at 115% of expected for my age and height and weight, on a pulmonary function test in July 2001. I retook the test in October of 2001 and was at 80% of expected. 79% would be failing the test. The doctor told me that the test came back normal and when i looked at the numbers i said to him yeah but i dropped 35% in 3 months and he said yes but you are still normal.

For neurological tests for peripheral neuropathy, emg/ncs can come back negative even if you have large fiber nerve damage because a certain amount of damage must have occured for it to show up on the test.
The skin biopsy you took also of course has percentages.
I just wanted to let you know about the percentages thing so that you can look for yourself and better understand where you stand at the present time and be better able to compare it to where you are in the future.

I will post my results as soon as get my report for comments hopefully of Glenntaj.

Thank you for your feedback.

--with the skin biopsy results is that the definitions of "normal" and "abnormal' were rather arbitrarily set by MacArthur and his colleagues at Johns Hopkins when this was first investigated as a way to detect small-fiber neuropathies (which are very difficult to detect, as there may be no other abnormal test results, including normal nerve conduction and electromyography studies).

The Hopkins researchers did skin biopsies on a range of what were assumed to be people with normal nerve fiber densities and found that there was a wide range of fiber density even in asymptomatic individuals. After playing with the statistics for a while, they designated those who had nerve fiber density levels below the fifth percentile and above the ninety-fifth percentile as being "abnormal".

I'm fairly convinced that those with nerve fiber densities in those areas have something going on, but I also think one can have neuropathies even within that "normal" middle range. The trick is that one doesn't usually know at what density levels one started at before symptoms. As Echoes implies, one can move a lot within the normal range over time, and to me that's an indication of something going on. If one was at the sixtieth percentile in young adulthood, say, and then after symptoms is in the twentieth percentile, one is still technically "normal", but that reduction implies some neuropathic process.

This is also why one needs a neurologist familiar with these protocols to interpret. They are also supposed to note the condition of the fibers, not just density--are they swollen/inflamed, is there excessive branching, are there signs of autoimmune degeneration.

My skin biopsy was done at Hopkins two years ago, and the results were as follows:
Ankle- devoid of nerve fibers
Above the knee- reduced in a patchy distribution
Thigh- normal, but segmented and breaking down
That along with a confirmation of SFN is all that appears on the lab sheet. There were no percentiles, etc. This way of expressing the results doesn't sound like anyone else's, but it was one by a Hopkins neuro at Hopkins, says Hopkins lab on the paper.
Other tests show large fiber neuropathy as well with muscle loss. I have CMT, with no sensation to above the knee. Hands and arms are also affected, with pinched nerves.

The neurologist at Hopkins asked if I wanted further genetic testing and a spinal tap. I said no, he agreed, and it was "goodbye and good luck".

I am curious if anyone else has results expressed in this way.

I have not seen my results yet. I know that my specimen was sent to John Hopkins. I will post here when I have it.
As you may have read my post, my neurologist advised me (through phone)that my skin biopsy result is negative. I am thankful about it but this makes me so confused because I have the symptoms of a PN.

I got a similar position from my doctor too when I asked him if I need to have more tests. He said "Lets just wait and observe."

The good thing is we have this forum. Reading the posts here gives me more information - more information than I get from all my doctors combined.

Hi. I got my skin biopsy result today. The result is not reflected in percentile. It reads as follows:

Distal Leg Right : The epidermal nerve fiber density and appearance are within the normal range.

Prox. Thigh Right : The epidermal nerve fiber density and appearance are within the normal range.

"Session Summary : The epidermal nerve fiber density is within the normal ranges at both sites and therefore there is no definitive evidence for a neuropathic process affecting small caliber sensory nerve fibers."

How can I get the results in percentile? Can the clinic of my doctor request it from John Hopkins? Or, is there a certain kind of skin biopsy protocol that does not yield the percentage but instead just a general impression?

How will I proceed from here in my treatment? My symptoms are still the same: very painful feet, prickly skin, deep and stabbing pins and needles. I no longer have the severe burning skin. I dont want my doctor to dismiss me like my symptoms are just "in my head".

Are there any others in this forum who have had a normal skin biopsy result but experiencing the PN symptoms?

I really want to know....
Thank you.

there should be a written record of what your nerve density was. it is part of the procedure to calculate that percentage.

http://www.ccjm.org/content/76/5/297.full

This is from the Cleveland Clinic Journal of Medicine

Skin biopsy
Skin biopsy is a minimally invasive procedure in which 3-mm-diameter punch biopsy specimens are taken from the distal leg, distal thigh, and proximal thigh of one lower limb. The procedure takes only 10 to 15 minutes.

Biopsy specimens are immunostained using an antibody against protein gene product 9.5, which is a panaxonal marker. Small nerve fibers in the epidermis are counted under a microscope, and intraepithelial nerve fiber densities are calculated and compared with established normative values. The diagnosis of small fiber neuropathy can be established if the intraepidermal nerve fiber density is lower than normal (FIGURE 1). Nerve fiber density may be normal in the early stage of small fiber neuropathy, but in this setting skin biopsy often shows abnormal morphologic changes in the small fibers, especially large swellings,24 and repeat biopsy in 6 to 12 months may be considered.

The diagnostic efficiency of skin biopsy is about 88%.21,23 For diagnosing small fiber neuropathy, it is more sensitive than quantitative sensory testing21,25 and more sensitive and less invasive than sural nerve biopsy.26 Intraepidermal nerve fiber density also correlates well with a variety of measures of severity of HIV distal sensory neuropathy and thus may be used to measure the severity and treatment response of small fiber neuropathy.27