Glycerol rhizotomy: spinal needle into trigeminal cistern, check with cisternogram, anhydrous glycerol infusion while pt stays still x 2 hrs. Better than alcohol, but highest recurrence of percutaneous txs.
Balloon gangliolysis: balloon into foramen oval, inflate x 10 min.
Pr: >90% success, but 20% recur in 6 yrs, 80% in 12 yrs
SE: facial numbness, cornel anesthesia, anesthesia dolorosa (loss of sensory, but persistent pain), non paralytic keratitis
Gamma knife radiosurgery (less technically demanding, long time for pain resolution)