Hello Board folk!

I need opinions...So, after a few years of being mis-diagnosed with RLS, the recent conclusion earlier this year (based on excluding other things) has been that it is SFSN. EMG/NCS, MRI, blood tests all normal. Physical exam shows lessened pin prick sensitivity below the ankle. Temp test never done. Vibration response normal.

Pharmacutical-wise: I've been on lyrica 2x/day for about 6 months with good results. I also take 1 5mg Vicodin as needed for breakthru pain (which occurs approx 5 out of 7 nights a week). Considering that I went thru tons of meds to get to lyrica and the vicodin use was previously a lot more--I think this is great (only using about 5 Vicodin pills a week).

But (there's always a but), having no proof of disease is sometimes problematic for me. I see a sleep specialist because it appears I also have ideopathic hypersomnia, the attending physician seemed to think it was ludicrous that someone taking "narcotics" should be prescribed stimulants. Seriously, I would prefer to take no Vicodin, pal! It's not like I get 'high' or am addicted to them (as time has proven).

Do you think I should seek the punch hole test with my neurologist? If it comes back negative does that necessarily mean I don't have SFSN? I just want to feel a little more secure with the diagnosis...my odyssey has been so windy that I almost feel like given a new symptom, or the meds becoming less effective, that the diagnosis may change. The doctor (and I) was positive it was RLS, who's to say the second diagnosis is really correct either?

......that it could be a good idea to have the skin punch biopsy done to verify SFSN. I am no expert and don't know much about whether a negative skin biopsy always remains negative as symptoms progress further or whether the skin biopsy can change. Sounds like you've had this for a while so hopefully any changes would already be evident.

It must be somewhat confusing for you having your diagnosis changed from RLS to query SFSN. Have you had a change of doctor to precipitate this clarification?

I agree with you when you say that "having no proof of disease is sometimes problematic for me". I am still undergoing diagnoses for cause of my PN but at the moment I feel like it is not a legitimate condition when it hasn't got a label. 'Illegitimate' is certainly the way one can feel when one is being treated by the medical system, especially when you are only experiencing symptoms but expressing no provable signs of a condition because of negative test results.

Hope you can resolve this for your peace of mind!

Is a punch hole biopsy the same as a nerve/muscle biopsy?? I haven't heard the term punch hole biopsy before. Thanks!

--and a lot less invasive.

The punch or skin biopsy is designed to examine intraepdiermal nerve fiber density and condition--specifically, the small, unmyelinated fibers that subsume the sensations of pain and temperature. It's a fairly new procedure, and still is only done at a handful of tertiary centers across the US (Cornell-Weill, Mass General, Jack Miller, Hopkins--though the latter has a program now through which any dermatologist can take the proper 3mm across/1 mm deep skin samples and send them in for analysis, which requires electron microscopy). Often, for people with normal nerve conduction studies and other tests, but painful neuropathies, this will be the only test that shows anything, though it rarely, if ever, points to a cause.

The nerve biopsy, usuallly performed on the myelinated sural nerve, involves a much bigger/deeper incision, as some muscle is normally biopsied as well. It may point to a cause for certain neuropathies--especially autoimmune vasculitic ones secondary to connective tissue disease--but the diagnostic yield may not balance the dangers from the cutting. One should not have this procedure done except by a real, qualified surgeon--there are too many stories of permanent damage/numbness when these are done by your run-of-the-mill neurolgist.

Does anyone know if punch skin biopsies are being done in Atlanta?

I can go on forever on the epidermal nerve fiber density biopsy, or 'skin' biopsy, which is not really a biopsy of skin as much as a piece of skin from which they determine the density of small nerve fibers. I utterly agree with Glenntaj.

It is confirmatory, in that it is never wrong. If you have abnormal results, they are indicative of small fiber neuropathy.

I don't like doctors taking potshots at diseases when the technology exists to do a solid, quantifiable diagnosis. PN or peripheral neuropathy has many manifestations. My feet did not burn one iota. My calf biopsy has less than 2fibers per mm. 7 is normal. My feet have 2.5 fibers/mm. The thigh is normal but showed sweat gland innervation was reduced. The fore arm was normal number of fibers but showed that the pattern of innervation was not normal, and the sweat glands were not innervated normally. My biopsy is 3 years old this month, and I am sure if one was done today, it would be the same or worse.

If I had not had this done, I would not have the 'diagnosis'. The numbness and tingling could have been MS....or some other disease, who knows. That said, small fiber neuropathy is akin to knowing you have a fever. What is causing that fever is a totally different issue. Now that I know I have small fiber neuropathy, other testing showed it is also autonomic, which means, for example....I don't sweat to heat. That is a critical thing to know. I also learned a lot from my tilt table test...and other testing for causes, which turned out negative. Other tests will likely be done.

Lastly, is the issue of causation, which takes a long time and tremendous work to figure out. Some causes are on the cusp of discovery of by some of the brightest minds out there....just reading their work makes me humble. I can't believe people come in that 'variety' of smart. It is like Steven Hawking smart, but in molecular biology and genetics.

I prefer to know if a disease is curable or not, treatable versus curable. Symptoms of PN can be treated with varying degrees of success depending on each and every individual's personal case. Treating the cause of your neuropathy may cure your neuropathy. Without knowing a cause, you can only treat symptoms.

There is no generalizing symptoms, causes, or treatment of the mystery of PN. The best we can do is share what we know, admit what we do not know, and support whatever choices that we all make as individuals.

High quality nerve fiber density studies are done, as Glenntaj said, at tertiary or what are known as research centers. I would love to see an idiopathic PNers who want to find a cause, get care at those centers. If you know a cause for your PN, it is less critical, as you can likely get treatment for the cause at a specialty clinic for your disease with consult to neuro. (Such as people with rheumatologlical disease and neuropathy who see both specialties, or diabetics or endocrinological disorders who also see neuros.)

Some people prefer not to keep searching for the cause of idiopathic PN, and that is fine too. There is an end to the internet, at least right now.