Hi Koala ..
I checked with the Yahoo search engine and there were quite a few references, this being one:
http://www.ninds.nih.gov/disorders/g..._neuralgia.htm
You'd probably find it by googling as well.
It seems to be quite rare.
I was interested in your query because 20 years ago for about a week I experienced real difficulties speaking and swallowing and thought it was part of my MS. The neurologist seemed a bit lost but prescribed tegretol which I didn't take. It seemed to get better of its own accord. There was no pain, however.
Hope your friend is OK.