The treatment only takes a few minutes. Eighty-five percent of patients achieve immediate pain relief and persisting numbness in the face is unusual and infection is rare. Re-injection may be performed, but glycerol injections become less effective after several are performed. This procedure, first described by Sweet is similar to glycerol injection. A needle-electrode is introduced through the face into the nerve in the skull base, once again using a brief anesthetic.
Patients develop some sensory loss.
Marked numbness of the eye is an unusual hazard and infection is rare. The procedure can be repeated. In this treatment a small balloon catheter is introduced through the needle into the nerve in the skull base. With the patient anesthetized the balloon is briefly inflated to compress the nerve and then removed. Infection again is a hazard.