Retrogasserian glycerol injection: a retrospective study of 112 patients.

From 1984 to 1989, 112 patients with typical drug-refractory trigeminal neuralgia were treated by retrogasserian glycerol injection. The present study assesses results and complications after a mean follow-up period of 3.5 years (range 0.1-5.5 years). One hundred and three of 112 patients (91.9%) showed complete pain relief 1 month postoperatively, and at the end of follow-up 80 patients (71.4%) were still enjoying complete pain relief (recurrence rate 20.5%). Abnormal facial sensations were noted in 49 patients, the most common complication being mild hypoesthesia (32% of patients), while paresthesia occurred in 19% of cases and dysesthesia in 3%. The corneal reflex was absent in 3% of patients and reduced in 5%. None of the patients developed anesthesia dolorosa, permanent masseter weakness, neuroparalytic keratitis, or diplopia.