Hello, My Husband Suffers From Post Hermetic Trigiminal Neuralgia. He

Hello, my husband suffers from post hermetic trigiminal neuralgia. He has been on so many medications and nothing is helping. He has also had gamma knife and nerve block injections. Do you possibly know of anything new that he can do? The medications that he takes right now are methadone, norco, baclofen, mirtazapine.