Chronic electrical stimulation of the gasserian ganglion for the relief of pain in a series of 34 patients.

The use of an implanted system for chronic electrical stimulation of the gasserian ganglion for relief of facial pain was described in 1980 by Meyerson and Håkansson. Between 1982 and 1995, the senior author (R.R.T.) performed gasserian ganglion stimulation in 34 patients for the relief of chronic medically intractable facial pain. The etiology of pain was peripheral damage to the trigeminal nerve in 22 patients (65%), central (stroke) damage in seven (21%), postherpetic neuralgia in four (12%), and unclassifiable cause in one (3%). All patients received a trial of transcutaneous stimulation (Stage 1). Successful trials in 19 patients (56%) were followed by implantation of a permanent system (Stage II). Trial and postimplantation stimulation were deemed successful when there was a reduction of pain by at least 50% whenever the stimulator was on. Success rates varied from five (71%) of seven patients for central pain to five (23%) of 22 for peripheral pain and none (0%) of four for postherpetic neuralgia. The median follow-up duration in successful cases was 22.5 months. Infections occurred in seven patients, all of whom had undergone Stage II treatment. Infections were more frequent when the stimulating electrode from Stage I was left in place for Stage II (six [43%] of 14) than when completely new hardware was used and prophylactic antibiotic drugs were administered (one [20%] of five). Other complications included iatrogenic injury to the trigeminal nerve or ganglion in three cases (9%), transient diplopia in two (6%), increased pain in two (6%), and various technical problems in 10 (29%). It is concluded that pain of central origin (stroke) is the type most likely to be relieved by this procedure. This finding is new, as the few other clinical series reported to date contain no patients with this type of pain. The risk of infection seems to be lower when completely new hardware is used for Stage II and prophylactic antibiotic drugs are administered.