Apologies if this is old news, but if it's carpal tunnel syndrome, then it's an inflammation of the radial nerve where it enters the hand through the carpal tunnel in the wrist. Main symptom is numbness in the thumb and first two fingers. The nerve gets inflamed and swells, and rubs more, and the problem gets worse, until you rest it. The only solution I could find was to keep the hand in a straight line with the forearm, so the wrist was bent as little as possible. Easier on a motorbike with flat bars than on a pushbike, where you have to have weight on the hands, and to keep the wrist straight you have to hang on with your thumbs or something. I fitted cowhorn bars (with bits at the end) to the MTB yesterday and it makes a big difference, as you can keep your hands in a more natural position. Same as riding on the brake hoods, I suppose. I'm not sure I can be bothered doing this with the Wisper, as the left grip has the integral 'throttle' and changing the bars for something radically different is going to be a major pain in the bum. Good luck with it.
Edit: that was in reply to d8veh. I think what you (mfj197) say about the bar ends confirms it.