Resolve Medicolegal has a number of Experts who are able to act for the pursuer. In their opinion, the key features are excessive exposure to pathological frequencies of vibration as determined by a lifetime exposure( its like radiation it accumulates ) if it reaches a certain amount, then the claimant may be potentially vulnerable to CTS.
If they are not diabetic and the surgery is partially or completely ineffective you can say on the balance of opinion they have DWP-CTS.