I did the QSART,finally after rescheduling 3 times.The tech showed me my lower than normal results on the sweat test and said I will have some answers next time I speak to my neuro.Not sure about the tilt table part as I saw my highest heart rate only reached 21.How convenient as it has no problem going above 30 at home.So does this mean I have small fiber neuropathy and I can become an official member of this board,I'm so excited.No not really but I am trying to keep my sense of humor,amongst other things.

Quick background,had 2 emg's a year ago indicating I had a "touch of neuropathy"barely noticeable on the readings and then the super professionals tried to tell me my 3rd emg did not indicate any neuropathy,but the needle part was off by one on my feet indicating "everyday wear and tear of my feet" as the neuro put it.Symptoms continue,luckily nurse practioner of the neurology department orders QSART.So what's next?A final dx or a biopsy?

I flunked the sweat test pretty badly...didn't turn purple.

I am hoping your heart rate is not below 21?? That is too low to sustain life. Normal is 60-100....at 20, you would likely pass out.

Oh no,I meant my heart rate didn't RISE by more than 21 BPM on the tilt table.

When I said sweat test I realized there are 2.The one I'm talking about is where they put the things on your arms and legs and it feels like bee stings for 5 minutes then they observe your sweat output 5 minutes later.

Tryng hard not to sound ignorant, does turning purple mean you are sweating? Or not? My problem is I don't sweat when I should, only when I shouldn't. Go figger!
I'd probably upchuck on a tilt table! Just trying memory foam mattresses makes me slitely nauseus and ready to pass out! If I upchucked? I'd prefer to do it on the docs' expensive shoes! Seems like a good retribution in kind?
Guess I should count myself lucky [?] that these tests weren't needed?
Good luck with it all? Ask questions, Cy's the expert and I'm only a 'patient'!
Hugs and hopes!!! 's - j

Doesn't have to be autonomic. I would think of skin biops....
What is your normal Heart Rate? I didn't get it from your post.

I have SFN for five years. my HR is about 50. My neurologist said it has nothing to do with my SFN. I hope he is right...

--during the sweat test, the chemical powder put on your body is designed to turn purple when exposed to perspiration--the more you sweat, the more like Barney you will look.

The other test that was mentioned is the sudomotor axon reflex test--small electrodes are placed on the skin to see if small transmitted charges can produce "normal" sweating.

I'm sorry,I should've mentioned I was also being tested for POTS.My heart rate was in between 78-85 and apparently my heart rate only went up to 104,while in the upright position.I saw the heart rate increase column and 21 was the highest number.All I want to know is if my sweat output was lower than normal,does that mean I have sfn?Or will they insist on skin biopsy next before a diagnosis?

It's been a year and I am so sick of waiting for a dx of what's wrong with me.If I'm positive for sfn,my doctors will finally take me seriously and start looking for what else is wrong with me.I've had a multitude of symptoms and things happen to my body that can't be explained by any bloodwork or other tests they've done so far,so all the doctors,including Cleveland Clinic tried to tell me this was all psychosomatic!!!!!

I heard the "psychosomatic" thing for more then 2 years - and the skin biopsy - stoped it.

It is a very simple procedure....

I had the autonomic workup before the skin biopsy. Every test in the autonomic battery yielded an abnormal result....so then they did the skin biopsy.

Seems to me that POTS is a pre-diagnosis to the neuropathy......or does POTS exists in the absence of a + skin biopsy? Maybe I am wrong, but, lots of these diagnoses boil down to SFN.

Yes, I had abnormal QSARTS which are not the same as the Sweat Test....The thermoregulatory sweat test is as Glenn said, when they apply orange powder to you and bake you. As Glenn said, you are supposed to turn Barney purple. I stayed totally orange. Pretty strange. I DO sweat tho....when I am active I sweat, or if it gets super, super hot, with dangerous heat indexes I seem to sweat....so, maybe they didn't bake me hot enough?? It was so long ago, I dunno.

I would love to have another skin biopsy to see where this disease has gone in all these years.

I have sfpn and have had a skin-biopsy but not any sweat test. It's interesting to hear about. I always sweat and still do from by head and groin area where I don't have PN so much. I wonder if they take that into account when doing sweat tests? I don't think I've ever sweated much from my arms and legs where I have the neuropathy....