Abstract
We retrospectively analyzed 5 patients (group P) who had residual intermittent pain and 5 without residual pain (group N) after radiofrequency thermocoagulation of the trigeminal ganglion for trigeminal neuralgia. The electrode of radiofrequency thermocoagulation was placed in the trigeminal ganglion where burst stimuli with 50 Hz gave paresthesia in the affected region. There were statistically no significant differences between the groups in the angles formed by the sagittal plane and the needle on the basal x-ray view, the ratios of the distances from the anterior edge of the oval foramen to the needle tip and the lengths of the short axis of the oval foramen, or the angles between the clivus and the needle on lateral x-ray view. The ratios of the distances from the infratemporal surface of the sphenoid to the needle tip and the distances to the clivus ranged at 0.50-0.79 for group N on lateral x-ray view. whereas, they were<0.50 or>0.80 for group P. Tactile sensation significantly decreased after thermocoagulation in group P versus in group N (1.8±4.7 vs. 6.2±2.7; P<0.05), as compared with the contralateral side. We conclude that patients who developed more intense impaired tactile sensation after thermocoagulation of the trigeminal ganglion for trigeminal neuralgia had residual intermittent pain. The position of the needle tip in relation to the oval foramen on lateral x-ray view and tactile sensation after thermocoagulation would indicate effective pain relief of trigeminal neuralgia after radiofrequency thermocoagulation of the trigeminal ganglion.
