Read about fascisculations and see if this is what you mean be skin shakes. These are very fine muscle tremors/twitches of sort that can happen anywhere on the body. Most people have experienced an eyelid twitching...this is sort of the same thing, but muscles in the legs, arms, etc.

http://en.wikipedia.org/wiki/Fasciculation

The heart pounding is more autonomic sounding. Did you actually experience this feeling WHILE the holter monitor was on, so they could see your heart's rhythm/rate at the time it was happening?? If not, then you may inquire about an event recorder for 30 days. This way you can push a button when it happens and it will record the activity at that time. Yes, everyone has some tachy rates at times, but it all depends on what you are doing to provoke it.

The lack of sweating can be autonomic...or medication induce (all depending on what you are taking---if anything).

Urination problems can also be autonomic, but typically it's more difficulty initiating urination and inability to completely empty bladder.

I don't know much at all about thyroid, so someone else needs to answer those questions. But if your TSH and other thyroid tests were normal, then I wouldn't worry about thyroid.

I have twitches all over now. For the past 30 years, they were isolated to my left leg only, but now I feel them in a variety of places...including my back muscles along my spine where they do indeed seem to pulse.

When I heard the term "Benign Fasciculation Syndrome" several years, that's what I believed I had that was affecting my left leg. Now, with the SFN diagnosis, everything is up in the air.

You talked about your heart pounding. When my SFN symptoms flare badly, my heart definitely does start to pound. I'm thinking this is my body's response to the discomfort with epinephrine production. I have a standing "as needed" prescription for propranolol (a beta blocker) which does seem to help when I'm really bad.

And of course when all this horrendously bad stuff is happening, my anxiety goes through the roof making my SFN symptoms even worse. There's definitely a snowball effect at work. I work really hard to try to keep my mind off of my symptoms when they're really bad.

You might want to read through this thread on a "Benign Fasciculation Syndrome" website. As the name indicates, BFS results in harmless twitching. The important thing on this thread is the discussion of anxiety and the toll it takes when you have neuro problems like ours. (Note, when you see references to "THE DISEASE I DON'T HAVE", they're talking about ALS.)

http://www.bfsrecovery.com/forum/vie....php?f=6&t=114