Percutaneous radiofrequency thermocoagulation of the Gasserian ganglion for severe trigeminal neuralgia

The incidence of trigeminal neuralgia is 3.5/100000 per year. While anticonvulsant medication controls symptoms in 70 per cent, the remainder may have intractable pain. Radiofrequency thermocoagulation (RFT) of the Gasserian ganglion enjoys a high initial success rate, with a recurrence of 15-24 per cent, and is an alternative to open neurosurgical procedures such as microvascular decompression. We reviewed 150 such patients referred to the pain clinic between 1984 and 1993. Ages ranged from 25 to 91 years, with one-third of patients being in their seventh decade. The pain ranged from 2 weeks to 25 years. Failure of medical therapy was the primary indication for percutaneuos RFT. Seventy-five patients received a single lesion, with 47 patients requiring multiple lesions. Thus ove the 9-year period studied, a total of 199 RFT lesions were reviewed. Ninety-seven per cent experienced immediate relief, with a further 1.7 per cent having a successful repeat RFT procedure within 1 week. The overall recurrence rate was 25 per cent, 19 per cent of these responded to aqueous phenol injection a further 21 per cent were controlled by adjusting medication. Fifteen per cent required repeat RFT. Excluding those with no recurrence, the median (interquartile range) duration of relief from the RFT was 1.9 years (0.75-3.25). Morbidity included partial corneal reflex impairment (10 per cent), facial dysaesthesia (8 per cent), and masseter malocclusion from motor block 2 per cent. RFT may be the technique of choice for intractable trigeminal neuralgia, particularly as it is less invasive and carries significantly less morbidity than neurosurgical microvascular decompression.