Suggest Treatment For Shingles

My father is 72 years and has been suffering from shingles on his head for the past 3 years or so.
He has tried almost everything just short of taking his head out.
The last doctor he want said he will number the nerves with pain killers and hope that works if not he will burn the nerves on the head..

I just want to check what are the side effects of the procedure…and also is there anything else my father can do.