hi all,

i'm moving up in the world here....one step up!......i'm usually on the rsd board (bad hands, so excuse my rotten typing)....however, the new neuro thinks that the problem with my feet might be PN rather than RSD, tho he's not ready to rule out erythromelalgia.

i've been reading a bunch of posts here and it sounds like PN and RSD use many of the same meds, tho i haven't heard anyone mention topomax, which did me more good than anything till i had to stop it......i'm currently on no meds at all since i've had so many adverse reactions in the last year.....i do use a lidocaine cream and anti-inflammatories.

i had a lumbar block a few months ago that helped a bit with the pain in my feet, but has long since worn off....and that's one of the things i was hoping all of u could tell me.....do procedures like that generally help with PN?...i've never been sure if the block helped or if it was just a question of timing, and the flare-up was dying down anyway.

which leads to my next quesiton....does PN tend to be an up-and-down sort of thing, or is it more stable?....does physical therapy help?....does PN respond to hot or cold?

i have a feeling that RSD and PN are not all that different, but if i am dealing with 2 separate ailments here, i'd like to know a bit more about it....the neuro mentioned doing an EMG, but i told him that unless he planned on general anesthesia, the answer was NO......he says that since it wouldn't change his treatment plan, it didn't matter much, tho he "would like to see what's going on".......it will take more than that to get me to agree to another emg.

thx for any info u can give me.

best to all,
liz

The most current diagnostic technique for small fiber neuropathy (PN) is the epidermal biopsy. It is not widely available yet. (There are also tests for autonomic neuropathy, a type of PN or small fiber neuropathy.)

They do a punch biopsy of skin, and a little fat if you are really lucky (which can rule out amyloidosis thru stained with Congo Red). They take skin from 4 sites under local anesthesia. I didn't find it too painful, but the sites do bleed for a few days and a bandaid won't do the trick, you have to cover it with gauze. I wasn't allowed to swim for a month until it all healed. It took 6 weeks to get my results.

At this point, I think mostly research facilities do them. I am not sure how often general neurology clinics do them. EMGs will not diagnose PN. They actually count the nerve fibers present in the sample. One is taken in the interior foot near the ankle bone, one in the calf just interior to the knee, one in the inner thigh and one in the upper fore arm just interior (medial) to the elbow. You get a small white scar the size of an 'emoticon'.

I am not sure if they will want to do this with your RSD, but you can always ask about it. I have severe PN (idiopathic sensory and autonomic) and normal EMGS.

You will see lots of people on Lyrica, and that is fairly similar to Topimax or toprimate (generic).

I can not take very many medications without severe reactions, or no reaction what so ever. I have a limited repitoire....I have learned from experience!


Hope the info helps.

EMG's will not diagnose small fiber neuropathy, however they can and do diagnose large fiber neuropathy if it is advanced enough.

Liz, PN can be steady progression, say the same, remit and relapse or go away. It depends on the person , and how the PN developed, the cause, and in some cases how well you take care of yourself after you develope it ( nutrients, exercize, supplements etc. ) I had a lumbar block it did nothing for me. I think it would help in cases where nerve impingement in the back was the cause of the PN. There are no definites with PN as to cause, symptoms, or result. There are over 200 causes and many drugs used to treat it. I think Bob was over 60 drugs in his count, probably a lot more by now.

--between peripheral neuropathies, especially those that are small-fiber predominant, and reflex sympathetic dystrophy/complex regional pain syndrome/erythromelalgia (there's some dispute as to whether the latter are actually different clinical syndromes or all aspects of the same one), but there are also some differences in the differential diagnosis. The major ones are that the latter syndromes are more often associated with a partiuclar traumatic event, and that they are usually associated with trophic changes in the skin as well, which is not generally associated with peripheral neuropathy.

They both may be associated not only with burning, stabbing pain and with autonomic dysfunctions, and yes, many of the same meds are used for symptom relief in both.

Since overactivity and inappropriate signal maintenance in the sympathetic neurons is thought to be one of the mechanisms involved in RSD/CRPS, one treatment that is often tried early in the course (if one can do it in time) is sympathetic nerve block, a treatment not normally done for diagnosed peripheral neuropathy.

big thanks to all of u.....i feel now that i have a slightly better understanding of the differences between PN and RSD.....the neuro didn't answer all my questions, because he said we needed to decide what we were dealing with first, and he wanted to spend the time checking out my feet.....reasonable, but frustrating.

cycleops, the biopsy is unlikely for me and that's okay, because i don't want anyone doing anything invasive if i can avoid it.....that's one of the reasons i asked about using blocks for PN......the last block didn't make a huge difference, and i'm not having another one if the (minor) improvement i had was a coincidence.

heyjoe, it sounds like PN can be as mysterious as RSD.....our gang likes to say that the initials stand for "really spooky disease", but i think at least half of all neuro problems qualify for that designation!

glentag.....i am LONG past the stage where sympathetic blocks r likely to help (or be useful for dignosis) which is one reason it's hard to pin down the cause of the foot symptoms.....i suppose some of u have run into the same thing, but with RSD it can take a long time to get a doc to believe u, let alone treat anything....i would guess that idiopathic PN could cause the same sort of problems.

i have other questions that i forgot in my first post....do noise and/or vibration trigger pain with PN?....or is that a sympathetic reaction peculiar to RSD?.....i get that with my feet, which is why i think it's just RSD spread (it feels exactly like my arms)....does anyone know if PN could be genetically related? (my mother had trigeminal nuralgia, a thought which scares the he** out of me).

i'm amazed at the understanding y'all have of RSD......i'm kind of ashamed to admit that i really don't know much about any of these neuro conditions except the one i have.........thanks again for your help!

liz