My Wife HS A Tingling In Her Tongue. It Is

My wife HS a tingling in her tongue. It is driving her crazy. It s in he tip and neurosurgeons and neurologists both fail to know what is going on. I would like to know where to expand the information widely to see who on this planet has had a similar problem- no pain killers work, and the tingling goes on. It is chronic, constant, and with no cure so far, what say you guys?