Yes TN can cause migraines. It also causes about a thousand different other episodes of pain, each individual to the other. None of us are qualified to pick out each side effect and tell what to do with it. It is so sad when some one is hurting because of this disease. A good neurologist is a must. Tell your friend to seek qualified help and get to the root of the problem. Let us know what happens.
Take care, Doodle bug7