Percutaneous retrogasserian glycerol rhizolysis for treatment of trigeminal neuralgia. Technique and results in 191 patients.

Percutaneous retrogasserian glycerol rhizolysis (PRGR) became a diffuse and valuable method for treatment of trigeminal neuralgia, following its introduction by Hakanson in 1981. Its main advantages are: a) mild postoperative facial sensory loss, b) simplification of the technique, c) reduction of costs. Our results in a series of 191 patients treated between September 1983 and September 1990 are reported. The procedure was performed according to Hakanson's method with minor modifications. In 11 cases (5.7%) we failed to pierce the foramen ovale; the procedure was successfully repeated a week or two later. In 17 cases it was impossible to obtain CSF from the needle. Complete relief of pain was achieved in 177 patients (92.7%), in 124 (64.9%) immediately, in 53 (27.8%) within 6 days; the operation was unsuccessful in 14 (7.3%). Postoperative sensory evaluation showed: no sensory loss in 33 cases (17.3%); hypalgesia in 8 (4.2%); mild hypesthesia in 88 cases (46.1%), confined to the affected divisions in 45 (23.6%), exceeding it in 43 (22.5%); moderate hypesthesia in 62 cases (32.4%), restricted to the target divisions in 36 (18.8%), exceeding them in 26 (13.6%). No case of anesthesia occurred. Complications of PRGR were: circum-oral ipsilateral herpetic eruption (herpes simplex type), spontaneously and completely regressing: 63 cases (33%); minor dysesthesia, seldom reported as painful: 33 cases (17.3%); impairment of corneal reflex: 19 cases (9.9%), the first branch being the target of the treatment in 11; regressive masticatory weakness; 11 patients (5.7%); aseptic meningitis, promptly regressed: 2 cases (1.0%). Follow-up ranges from 1 to 7 years (Sept. 1983-Sept. 1990). A recurrence was observed in 44 cases (23%): in 15 patients (7.8%) a partial relapse occurred, well controlled by drug therapy and not requiring further surgical treatment; in 29 cases (15.2%) a new percutaneous procedure was required. The mean time of recurrence was 30.5 months. The recurrence rate in the patients of our series at the end of the follow-up period was 23%. Glycerol produces a weak neurolytic lesion, that generates minor post-operative facial deafferentation; it is the best technique, in our opinion, for treatment of tic douloreux.