The goal of surgery for trigeminal neuralgia is either to stop the blood vessel from compressing the trigeminal nerve, or to damage the trigeminal nerve to keep it from malfunctioning. Damaging the nerve often causes temporary or permanent facial numbness, and with any of the surgical procedures, the pain can return months or years later.
Radiation. Gamma-knife radiosurgery (GKR) involves delivering a focused, high dose of radiation to the root of the trigeminal nerve. The radiation damages the trigeminal nerve and reduces or eliminates the pain. Relief occurs gradually and can take several weeks to begin. GKR is successful in eliminating pain for the majority of people, but sometimes the pain may recur. The procedure is painless and typically is done without anesthesia. Because this procedure is relatively new, the long-term risks are not yet known.
Source: Mayo Clinic