If drug treatment is found to be ineffective or causes disabling side effects, one of several neurosurgical procedures may be considered. The available procedures are believed to be less effective with type II (atypical) trigeminal neuralgia than with type I (typical or "classic") TN. Among present procedures, the most effective and long lasting has been found to be microvascular decompression (MVD), which seeks to relieve direct compression of the trigeminal nerve by separating and padding blood vessels in the vicinity of the emergence of this nerve from the brain stem, below the cranium. 
Microvascular decompression involves microsurgical exposure of the trigeminal nerve root, identification of a blood vessel that may be compressing the nerve and gentle movement of the blood vessel away from the point of compression. Decompression may reduce sensitivity and allow the trigeminal nerve to recover and return to a more normal, pain-free condition. While this generally is the most effective surgery, it also is the most invasive, because it requires opening the skull through a craniotomy . There is a small risk of decreased hearing , facial weakness, facial numbness, double vision , stroke or death. The risk of facial numbness, however, is less likely with procedures that involve damaging the trigeminal nerve.
The three divisions of the trigeminal nerve come together in an area called the gasserion ganglion . From there, the trigeminal nerve root continues back towards the side of the brain stem , and inserts into the pons. Within the brain stem, the signals travelling through the trigeminal nerve reach specialised clusters of neurons called the trigeminal nerve nucleus . Information brought to the brain stem by the trigeminal nerve is then processed before being sent to the cerebral cortex, where a conscious perception of facial sensation is generated.