It's taken nearly 6yrs for them to find out I have vasculitis,and if I hadn't pushed for a nerve biopsy,I would be none the wiser.My Neuro thinks the vasculitis,kick started the PN my GP thinks it was the other way around (makes no difference to me) To tell the truth,I still think they're missing something.If it takes me another 6yrs to get the final results, so be it..........