It's confirmed...and should I go for a nerve biopsy?
 

I had a skin biopsy a couple weeks ago that was sent to Columbia for analysis. I saw my neurologist and the biopsy confirmed I have small fiber damage. Since all the blood tests can back negative, he said the only remaining test would be to do a nerve biopsy. He said the three likeliest causes are my Crohn's Disease, vasculitis or hereditary. Since no one in either side of my family has had neuropathy, he doubts that as a cause. He said a nerve biopsy would leave permanent numbness in the area where the nerve is taken.

Has anyone had a nerve biopsy and how important do you think it is that one is done?

Lots of opnions on this!
 

Hi - I had a sural nerve biopsy - pros and cons...

First, I'd be sure its done by someone experienced in doing it (they took it out of the back of my calf and severe numbness starts mid-calf and goes down whole right side of foot - now - I pretty much had lost feeling anyway - but usually is done on your foot - so area affected is much smaller)
The incision healed in about two weeks - no real pain - but I still to the day get what feels like shooting electrical shocks around the scar itself.....

However, it helped my docs see immidiately (after waiting six weeks for results actually) - how severe my neruopathy is, the exact type of damage that they really couldnt totally decipher on my NCS/EMGS - and as a result even though I had it done 5 years ago my current neruo - who I started seeing a year ago - reviewed the biopsy and put me on IVIG - to try to stop any further progression - based on what he saw on these results.... also, was able to rule out other conditions.... (and IVIG is the only thing that has helped give me more energy and is improving my balance)

Overall - I'm glad I had it done because it gave us lots of information - but again - be sure to have an experienced doctor do it!

What's the point?
 

This issue has been discussed over the years. While it is true that the sural nerve biopsy is still considered the gold standard for diagnosing SFN (small fiber neuropathy), I would argue that it is unnecessary in cases where the dx can be established by skin biopsy and clinical presentation.

BTW, I think that the overall clinical presentation, which would include things like medical history, social history, etc., is by far the most valuable tool for clinical diagnosis. That's why it is so important to find a neurologist who not only is very skilled in these areas but also very thorough (in other words, takes all the time that is needed).

If the sural nerve biopsy could tell you anything at all about causation, then it would be a whole different scenario. But the procedure will do absolutely nothing beyond giving you a more precise picture of SFN damage.

If you are thinking you need the biopsy because you are still not certain that the diagnosis is correct, then you need to ask yourself why do I feel that way (neuro not thorough enough, etc.). And then you can take the appropriate actions to get the certainty that you need, without a sural nerve biopsy.

cons
 

There are a lot of con's to the biopsy, as rfinney lists. If there is no evidence of vasculitis (blood tests and looking at your skin and nails), it's unlikely to make a diagnosis. There are a lot of blood tests to do to look for causes, but unfortunately, most of us will remained undiagnosed formally, and just learn to live with that, figuring out as we live longer what works for our nerves or doens't, and what's going on with our health.

I'd like to refer you to www.lizajane.org.

It's a website I put up that lists all the tests that can and should be done to look for a cause.

But, first is history---when did it start, how did it develop, what other symptoms?
toxic exposure, medications, etc. Most diagnoses can be based just from getting a good history of what happened.

Then, there are blood tests which are indicated for motor or sensory disease, or disease that might be due to spinal stenosis. Please look at the charts and see if you have all necessary tests.

Ask your doctor for copies of EVERYTHING. You own your lab results. Keep them and guard them well. Only you will be really careful to follow them over time.

If you have questions about the charts, please let me know.

My only question is what did the.....
 

spinal tap tests say? I came up negative on the blood work & MRI's and positive on all the nerve conduction tests. The swing vote was the presence of anti-bodies in the serum from the spinal tests.

If you get deep into your insuance plans policies & procedures you CAN access the approved tests and treatments for neuropathies. I've found that my plan and several others consider nerve biopsies a very last resort for neuropathy dianoses.

I experienced one neuro who wanted to do a biopsy. I'd refused, as I felt I'd met a sort of 9 out of 10 rule. In that I'd met all criteria but that of a biopsy. I'd get copies of all the tests and any other reports and work them into LizaJane's reports. I would bet that there are some things there that will/should point to that extra step for the biopsy. To do such procedures, docs really have to jump thru hoops for justification - If I were you, I'd be interested in seeing what all those hoops are.

I hope BobB[Nide44] comes along soon to talk about his biopsy experiences. I am also very glad that you had the punch biopsy rather than the seural one Kmeb had.

In the meantime, I wish that you have at least one pain-free moment today! -j

I can't see any reason for skin or nerve biopsy, as far as i know it only shows how much damage there is to the nerves, it doesn't give any more clues of why this is happening, i would think it would be only usefull to use in comparing the damage over time, but thats easily done by how you feel anyway [improvement or worsening] of the disease i mean.
I had small nerve damage and just to confirm it, my neuro sent me for a test that measures how you react to heat and cold sensations and a vibration test as the small nerves job is to do excactly that, its a very simple test that is only done to evaluate the damage of the small nerves.
I hope your neuro is an expert in neuropathy because there are many that are not and will take you on a merry go round.

Thanks for your input
 

I had pretty much already decided that not much would be gained by doing a nerve biopsy at this time. My neuropathy has not progressed since my Crohn's and ankylosing spondylitis was brought under control two years ago. My neurologist, who by the way specializes in neuropathy, said a biopsy might be necessary in the future should the neuropathy change in any manner.

While I am relieved to have the correct diagnosis, I am very angry at the road getting here. My PCP and first GI dismissed my complaints of symptoms 3.5 years. It was only when I could no longer stand the pain and was forced to beg my PCP for help did he send me for an EMG. That was six months after symptoms began. It took another 1.5 yrs to get my PCP to give me the insurance required referral to a neurologist. That neuro misread the EMG reports, did some more blood work, and pronounced that my large fiber neuropathy was idiopathic. Then I got 100% smarter about PN by reading this group's postings, the articles you stickied at the old BT, and using Lisa Jane's charts. I realized my old neuro had no clue what he was talking about and had not done the necessary tests to make ANY informed decision about my case.

My husband's death necessitated an insurance change and I researched and found an excellent neuro. This guy has done the tests not previously done, redid the EMG/NVC, and felt that the punch biopsy was in order to confirm the small fiber neuropathy and the extent.

I also need to take some responsibility for not being more aggressive when I was initially told I had PN. I was far too accepting of what I was told. However, I was dealing with two other diseases that hit me at the same time and was bouncing from specialist to specialist. Lesson learned.

Thanks for all the help you have given me these last couple years. You have made a HUGE difference....

Ides,
Your story is similar to mine.
I had the Skin Punch done, and see no need to go farther at this time.
Over the years, I've read horror stories about the sural Test's long term after affects. Even when done by an experienced person, the lasting effects are there 95% of the time. Many have said that the pain afterward (for years) is worse than the PN. I don't need to take that chance at this point in time.
Maybe if my PN really progressed severely, I'd consider it. But just for confirmation? I don't think so.

Since there is the option--
 

--of skin punch biopsy for confirmation of small-fiber neuropathy--this, by the way, should be considered in those with neural pain or numbness symptoms but with fundamentally normal EMG/NCV testing and no other "smoking gun" test results--there are relatively few instances in which sural nerve fiber biopsy should still be performed. (A lot of neuros who suggest it are not aware of the skin biopsy option, or don't have access to the microscopy needed to analyze it.)

Diagnostic yield is not very high in sural nerve biopsy (though, to be fair, it's almost zilch in skin punch biopsy--that is used more to confirm small-fiber nerve damage in those with consonant symptoms, and rarely will reveal a cause). But, a few instances in which it might be useful, in that it might not only reveal a cause but might have an effect on proposed treatment, are when neuropathy secondary to vasculitis is suspected, when amyloid (either familial or secondary to blood cancer) is a possibility (in the latter case, when neuropathy may be a presenting symptom, a major blood dyscrasia work-up, including immunofixation electrophoresis, serum ionic calcium, and possible even bone marrow biopsy should be done first), or when certain infectious or hereditary neuropathies are suspected.

See:

http://www.neuro.wustl.edu/neuromuscular/nother/bx.html

As is indicated here, for many inflammatory processes which may produce asymmetrical symptoms, myopathy may also be present and a muscle biopsy should be performed at the same time.

Your b12
 

Seems to me that with the low B12, you really don't need anymore tests, anyway. You've got two autoimmune diagnoses, and a low B12 which, for you, could either be malabsorption from Crohn's, or autoimmune from pernicious anemia. I don't see how your docs could say your symptoms are out of whack for your electrical findings---PN is generally pretty severe, symptoms wise, by the time there are ANY nerve conduction abnormalities. Actually I'm surprised they did the skin punch when you had the abnormal conductions---I mean, the diagnosis was already made, really, wasn't it? Most people get a skin punch because their nerve conductions are normal and their doctors want to confirm a small fiber diagnosis.

How's your B12 now?