Pity I didn't spot this thread when it was first posted. I could have said Ulner nerve, but only as a guess as the wife has problems with hers. (don't ask me anymore about it tho as I do the usual husband thing by showing lots of interest, wellllll, there's always something wrong)
She also had carpel tunnel and the muppets wanted to operate on both wrists 3 days before Xmas when she was first going to get it done.