Patients with V3 trigeminal neuralgia — particularly those with a large foramen ovale — may get greater benefit from bipolar vs unipolar radiofrequency thermocoagulation, according to research presented at the American Academy of Pain Medicine Annual Meeting, held April 25 to 29, 2018, in Vancouver, Canada.
Trigeminal neuralgia is commonly treated with percutaneous radiofrequency thermocoagulation of the Gasserian ganglion. This is achieved through the foramen ovale. In the current study, investigators sought to determine whether targeting the Gasserian ganglion further downstream (ie, at the point where its sub-branches exit the skull through the foramen ovale) with bipolar radiofrequency thermocoagulation may yield additional benefits in this patient population.
A total of 26 individuals with V3 trigeminal neuralgia and a large foramen ovale (ie, diameter >6 mm) received bipolar (one needle each on the inside and outside of the foramen ovale; n=14) or unipolar (one needle in the middle of the internal foramen ovale; n=12) radiofrequency thermocoagulation. Needle insertion was carried out under computed tomography guidance, and tests were conducted with 0.5 mA to 1 mA current. Radiofrequency thermocoagulation was carried out at 90⁰C for 120 seconds.
Although more study participants receiving bipolar vs unipolar radiofrequency thermocoagulation experienced masticatory weakness (8 of 14 vs 3 of 12, respectively) and the procedure was lengthier for bipolar vs unipolar radiofrequency thermocoagulation (17.4±5.3 min vs 14.2 ±4.7 min, respectively), none of the patients in the bipolar group experienced residual pain or had recurring pain (vs 2 of 12 patients and 1 of 12 patients, respectively, in the unipolar group).
“For the patients with V3 trigeminal neuralgia who had big foramen ovale…the bipolar approach might be a good alternative to reduce the residual pain and short-term recurrence,” concluded the study authors.
Huang B. Effect of bipolar radiofrequency thermocoagulation of non-Gasserian ganglion through big foramen ovale to treat V3 trigeminal neuralgia. Presented at: AAPM 2018; April 25-29, 2018; Vancouver, Canada. Abstract LB001.