I asked a regular Chiro about this. He said that he felt the problem with 'specialist' chiros is that they tend to be very keen on their particular area of speciality but that they keep their patients going back to them 'forever' whereas if he can't fix somone within a couple of months he will refer on. He said there is no real research evidence for upper cervical in relation to cranial nerve problems but that also there will be and are cases where the miraculous does happen. So his advice was if the pain is bad enough by all means give it a try, it's not impossible that it won't cure you but if it doesn't help don't keep going. I considered it but in the uk there is only one NUCCA practitioner in London and the cost of treatments and travelling, time off work et, x-rays was staggering.