Hi all,

I experience flare ups triggered by exertion, stress or lack of sleep.

Flare ups consist of ~3 days of burning arms and legs or what can be described as an excruciating 'acid under the skin' feeling. This is followed by 2 days of very tender muscles in my arms and legs presumably as a result of the nerves being irritated or irritating my muscles. I also experience varying degrees of fatigue during my flare ups.

I have no numbness or discoloration or swelling etc... Only other remarkable thing I've noticed
is that recently when I'm in the acute 'burning' phase I get lightheaded when I stand up and my legs will shake or spasm on standing.

When I'm not flared up I have no symptoms. Is that strange?

I've had these flare up for the last 6 years and I guess I'd just like to find one other person in the world that experiences the same thing. Just one damn person lol. Does anyone have any insights or experience similar flare ups?

The best I've come up with is that this is a small fiber sensory neuropathy but I'll have to confirm with my next neuro.

Thx

Could be HNPP...
http://www.hnpp.org/hnpp_symptoms.htm

Went to see a new neuro today. He did a good workup including NCS, he basically said that my nerves are fine but he theorized that my small fiber neurons are just hyper excitable. He didn't think that a skin biopsy would uncover any pathology.

Showed him that my TSH had recently tested high and he didn't completely rule that out as an underlying trigger.

Unfortunately he didn't have any compound creams that he prescribes for burning.

Unfortunately, the ONLY test to uncover answers about the small fibers IS the skin biopsy. The NCS (and EMG) is unable to detect issues within the small fibers.

It's too bad he won't pursue this for you so you may confirm/deny SFN.

Salut en bloc, he told me that here in Canada there aren't many places that do skin biopsies.

When I was in University about 15 years ago I would suffer from bouts of respiratory alkalosis due to anxiety. I'd feel really dehydrated and had to lie in bed for a day or two till my ph balanced itself.

Although I rarely get noticeably alkaline anymore, this is still interesting because I was just reading about how alkalosis triggers neuronal excitability which is what this neuro thinks I have.

I also read that caffeine has an excitatory effect on the nerves and makes them more apt to reach their firing threshold. I'll experiment by going without coffee next time I have a flare up and see if it helps at all.

Does anyone know what sensation/s is/are associated with nerves firing?

There are tests that help identify small fiber neuropathy, such as a sweat test (identify if there are areas you are not sweating), sensitivity to vibration, heat, & cold. They can test such things at a specialized facility such as Mayo, I know there are others. They told me they don't generally do biopsies anymore because they can get as much info from these other procedures, which I suppose have less risk to the patient. They have designed and built their own devices to perform these tests, at least it appears so.
Ron

--for small fiber neuropathy is still, as of this writing, a skin biopsy to enumerate the density and condition of the small unmyelinated fibers in "hairy" skin (the type with hair and sebaceous glands).

There are some other avenues of research that are hoping to be able to do this without taking out a chunk of skin--some microelectric conductivity tests patterned after quantitative sensory testing (another, older technology for attempting to determine small fiber function) among them--but those seem to still be some years away from being determined valid and/or reliable.

Just wanted to chime in. You can have small fiber neuropathy, and have normal tests for the above. I feel vibration fine, heat and cold fine, etc, and my sweat test came back totally normal.

I do, however, have the small fiber neuropathy symptoms (non length dependent, burning, shooting, numbness, pressure pain-they all wax and wane), and my two punch biopsies came back with significantly low nerve fiber density, and I was finally able to get diagnosed. So I think the biopsy is really the only sure fire way to know.