There is no evidence whatsoever that the sympathetic ganglia have any regulatory function on sweating

There is no "signal that tells the body to sweat excessively". The nervous system doesn't work like that. Worse, it implies that there is some separate signal that tells the body to sweat "normally" which, again, is implied to be unaffected by the surgery. It's nonsense and an affront to all that is known about neuroanatomy and neurophysiology.

Of all the lies and distortions, this is the one that pisses me off the most. Not only is it demonstrably false, it is criminally misleading in terms of what it leads the patient to expect. There no evidence whatsoever that the sympathetic ganglia have any regulatory function. Regulation if sympathetic activity occurs in the brain, not the sympathetic ganglia.

Why the hell don't they call it what it is?: sympathetic denervation surgery (which is a fancy name for a particular type of nerve injury). It eliminates excessive sweating by eliminating the ability to sweat at all (anhidrosis) over a large area. It achieves this end in the most brutal way possible: by permanently destroying the neural pathways. Any statement or implication that sympathectomy reduces sweating to normal levels or improves the regulation of sweating in any way is a boldfaced lie.
http://etsandreversals.yuku.com/topic/4918/Lies-from-your-government