There seems to be a lot of CTS sufferers here. I used to have it really badly (up to the point where i didn't have the strength or feeling to use the front brake) and discussed the surgery with my GP, but decided against it for various reasons. However, I did a bit of research and I have managed to reduce the symptoms to a fraction of what they were, to the extent that I don't really think about it any more. For what it's worth, and bearing in mind that I am not medically qualified in any way (except First Aid at Work!), this is what works for me:
The problem is with inflammation of the radial nerve that serves the thumb and first two fingers. It goes through the carpal tunnel between the bones of the wrist. If the nerve gets irritated, it swells and rubs on the inside of the carpal tunnel. This makes the inflammation worse, and the cycle continues until the fingers are numb and painful and you have to stop what you are doing. The standard non-surgical answer is a cast that you wear on your forearm and wrist that keeps the wrist straight. It places the nerve in the best position so it doesn't get irritated and used long term can actually heal the condition. I took the logic of this and applied it to riding a bike. When we ride, we often hold the bars with the wrist cocked back slightly. This is putting strain on the radial nerve and forcing it into contact with the carpal tunnel, which then starts to irritate it, and so on. Same with using a computer mouse, which is also a problem for me. If I start getting numb fingers, I consciously straighten my wrists, so that from the forearm to the first knuckles is a straight line. It feels a little odd to ride like that, and I can't do it for long, but it seems to ease the problem. Sometime I add a few fist crunches for good measure.
The bar position thing might explain why people are getting it worse with raised bars. The lower the bar, the straighter my wrist is, perhaps others the same?
So, first sign of tingling or numbness:
1. Wait for a period of light traffic!
2. One hand at a time, take it off the bars and dangle it straight downwards
3. Fist crunches to relax the fingers
4. Hand back on the bar and keep wrist straight for 5 minutes if possible.
Left hand is easy to do. For the right, I wait until I have a slight downhill and run with the clutch in for a while. It only takes 10 seconds or so before you are back with both hands. Choose your moment wisely
As I say, this works for me and may help someone else.