Have you heard of this simple SFN test?
 

I'm in another online SFN group and someone in that group posted about their positive experience with finding a Neurologist who really knew SFN.

This woman had a negative punch biopsy initially. She found this new neurologist 2 years later who put lidocaine cream on her fingertips, waited a few minutes, and the result was her fingers didn't winkle up. Apparently, if you don't have nerve damage, you fingers will wrinkle up. Very interesting.

This woman did have another punch biopsy after that and it was indeed positive.

I will try this... I know that according
To the doctor who did my arm EMGs
When I was pregnant years ago, I had
Significant damage then.

Okay... I just did this test with the lidocaine Aspercreme
And my fingers (I did the left hand) did wrinkle some.
Not as much as a long bath would do. About 1/2 as much
As a bath.

I don't have any numbness or pain in that hand either.

http://www.ncbi.nlm.nih.gov/pmc/arti...r-04-00126.pdf

I hope this link works.. This iPhone can be difficult.
If the link doesn't work, I'll get it again tomorrow.

Anyway, this link explains the lidocaine test and even
Has 1 to 4 grades of wrinkling. ;)

Would little pieces of a lidocaine patch do the same thing, you think?

<edit>

I tried putting two on my fingers and two n my toes. Didn't notice anything, but it was probably a bogus test.

Interesting paper.
 

From the mechanism described, this would seem to be best at detecting degrees of small fiber autonomic neuropathy.

What also struck me, though not in a good way, is that the authors acknowledge that small fiber neuropathy is generally the first presentation in diabetics (it often remains predominantly so), that EMG/NCV cannot detect small-fiber neuropathy, but they sort of dismiss skin biopsy with the phrase "IENFD as a screening test for small-fiber dysfunction in diabetes cannot be used as a screening tool due to its invasiveness and need for high-level expertise in obtaining and interpreting the sample."

It would me much more instructive, and clinically convincing, to see how this method correlates with skin biopsy results, as the latter is the current gold standard for determining small-fiber neuropathy. Also, skin biopsy is hardly invasive and it is not hard to obtain samples--the biopsies are punch biopsies--though it does require electron microscopy and special stains to examine samples (which perhaps Singapore has limited or no access to). Perhaps this will be tried on a large scale at a neuropathy center soon.

I think the lidocaine has to be present in a concentrated amount.
The patches release only some over a long period of time-- a trickle effect.

So concentration may be a big factor and needed to get the wrinkling. Therefore, I do think the cream would be best to try.
My fingers started wrinkling within 10 minutes. In the study they mention 30 minutes. I sort of gooped it on and rubbed it in.
I didn't go past the first joint either or around the sides.

I'll do my right hand tonight. It tends to be more symptomatic than my left.

Is the cream you use prescription?

No... it is the new Aspercreme Lidocaine that this thread is about.

The Emla in the study is very similar:
from https://en.wikipedia.org/wiki/Lidocaine/prilocaine

The Aspercreme is only lidocaine at 4% strength.

Emla was originally RX and used prior to biopsies, wart removal, or other dermatological lesions. It was commonly used for children having blood draws. Typically it was applied, covered with saran wrap for about 30 minutes, to force it deeply into the skin, before the tests.

Our FDA had resisted allowing lidocaine OTC ever. But times have changed, I see, and now it seems allowed OTC in strengths below 5%. This study was done with EMLA because the Aspercreme version was not available then....and also because doctors are familiar with EMLA.

I am performing this test later. I wish there was an area of the foot that worked. I have cobfirmed large fiber. I have to me, possible small fiber. To the lidocaine batman!

I am examining my left fingertips closely this morning. My middle finger and ring finger are showing the location of the wrinkles, as color changes still. But they are not raised and cannot be felt. I left the cream on all night. Maybe I should have washed it off?

That you for posting the links MrsD. This whole thing blows my mind.

And all you experimenters (a.k.a guinea pigs), please share your findings! :D

This is interesting! I'll buy some lidocaine and try it out tonight!

pinkie typing
 

applied, no tape, though I may pick some up. I'll update later. I probably should've before photoed my hands, for at least mysel.

Pinkie typing is difficult.

Hmm. Not a wrinkle. Not one. I put a dab on each finger tip, spread it out evenly and let it dry over the course of the half hour. Left hand first, right hand second.

I am going to pick up some of the tape mentioned in the NIH link tomorrow. We had those band aids in the house at the start of the summer, but it appears skinned knees and elbows depleted the supply.

I expected abnormal, not zero. So I wonder if the tape is that important.

I didn't put any tape on my fingers. But I did put quite a bit on.
I rubbed it in a bit too.

Yeah, me too. I will do it again later tonight if Iam up late, tomorrow if I am not. Not one wrinkle. I was not shy on the amount, figuring more was not going to change the results, but skimping could.

Hmm

I think the doctors used "covering" in the study, because they usually always cover EMLA cream. They are used to that and think it HAS to be done that way.

The current results are sobering, but at the same time I am thankful. I feel for people stuck with idiopathic for many reasons, but a diagnosis is a prison of sorts, at times.

Despite all my changes further testing has been at a standstill despite marching symptoms. This test points to small fiber issues, correct?

I have appointments next month. It will be interesting to see if this will bring about a punch biopsy.

My right hand results are very different from my left.
Only my rt ring finger is barely showing any wrinkle.
The rest show nothing.

A little history.. My father slammed our car door on
My right hand when I was 5 or so. It damaged my middle
Finger up to the first joint and so that finger is a bit crooked
And stiff today.I also had a mucoid cyst on it recently
which I finally cured. So I get sharp stabs in it fairly often.
The ring finger was smashed too but only across the nail.
It was a terribly painful thing and took a long time healing.
I remember crying in school too.. I couldn't do much for a long
Time.

This was the more severely affected hand during my pregnancy
too. So I am not surprised that I am not getting much if
any wrinkle results tonight on my rt. hand.

Like a salt crusted fish, my left hand. Not one wrinkle. Some of the extraneous skin around my nail bed looked white, like I was swimming, but as far as that swim wrinkle, no.

So, I don't know. I mean this is not a direct copy of that test, but it is pretty darn close, no?

It just has me feeling "huh", mostly because I know how I have felt all along. I am almost two years into massive changes. I have been waffling on trying gluten free for a few months, just to see if it offered some relief and I may just do that. It will mean I am not eating vegan for that period, as I don't see how I can pull that off.

I would love to see what other people are coming up with. I will test my right hand again in the morning. The are both equally bad, I think. My left always feels worse because I am right handed, or that is my line of thinking on the matter.

This is very interesting. I noticed that some are trying it on their toes. I'm wondering if it would show much there. My hands are more likely to show wrinkles if I'm in the water too long I think.

My feet are effected more then my hands so I'm wondering if this has an effect on results if I test it on my hands.

MrsD can you give your opinion on this?

I think you can assume the feet would be affected, if your hands are. My feet started way before my hands became affected.

When I finally got the thyroid hormone both improved about 80%.

Salt encrusted right hand looked the same.

When I was done with this test, I had hubby rub into my back shoulder some of the Aspercreme Lidocaine, as I had a spasm there that was driving me nuts. I also noticed that I had Tinel's in my right wrist badly as well. So I rubbed the cream into my inner wrist before bedtime. This morning the buzzing is gone and I can type MUCH better with fewer mistakes! So I am going to make the wrist my target nightly for a while. I just used a little bit.

IS there reason to bother with this test if your biopsy came back positive?

No I don't think so for the most part.

But some people here have had their PN improve and the later
biopsies show improvement too.

So you could do this test, yearly, on your hands and see if you
have some wrinkling occur, and then you might be one of the lucky ones to have improvement. (rather than another expensive biopsy.)

I Actually had 4% lidocaine aspercreme here. Put some on my finger and big toe for 30 mins and no wrinkling at all. So, that would indeed confirm the positive biopsy I received. Seems like this is a pretty good barometer.

Just tried it but only left it on for five minutes (no wrinkling). DIdn't realize you have to leave it on for 30 min and cover with tegaderm?? tape.

I did it...no wrinkles.

I'd do more than one finger. I did 4 fingers on each hand.

Each finger showed slightly different wrinkling degrees. Most of the wrinkling was on the left hand. And I had a tiny wrinkle on my right ring finger, but none of the other 4 fingers on the right.

I don't think one finger is a good test.

I went with the middle three of each hand. I can't see much point in a third go around, though I like the lotion in the tool box.

Thanks. Should I cover my fingers with tape ?

I tried this - no wrinkling at all.

Did you cover your hands with tape ? thx

I didn't. Was I supposed to? :o

I don't think covering the fingers is necessary.

Someone here can try covered vs uncovered.

I would wait a couple of days however between tests.
my fingers that wrinkled showed signs for a couple of days.

My right hand was giving me Tinel's sign when I did it. So I have been wearing my brace at night. I plan on retesting that right hand when the buzzing is no longer present. Should be in a few more days. It might give a different result?

And wrinkling indicates no nerve damage?

Yes, wrinkling is the desired result. No wrinkling suggests nerve damage according to the study.

Well, I guess it worked for me. No wrinkling at all and I already know I have nerve damage...it reminds me all of the time.