What a frighthening topic--because I am facing this issue too. My CP seems to be due to both wrist abuse (bad positioning plus too much computer work & mousing) and neck vertebrae issues. It really was manageable until October, when a serious rear-end collision just aggravated the h. out of my neck and led into constant wrist tingling. I have been getting therapy since Oct., and just got an MRI yesterday. I really want to avoid surgery.

My phys. therapist says that I need to be careful in my head/neck position when I'm riding. So...
- I am working on my posture w/ wt. training and trying to always correct it
- Wrist strengthening with squeezey toys and such
- A new bike to give me more options in sitting posture and hand positions than my current one. I'm not using my CP to justify this purchase, but it does factor into my decision-making!

Notes from my bike-related lurking:
Shifting more weight to your powerhouse, glutes, legs will take the stress off your arms. Raise the seat to be more level with the handlebars. Different handlebars (straight mtb bars don't give you many options). I heard that extra cushion-y padding might mask a problem while seeming to alleviate it.