Cardiovascular responses during percutaneous radiofrequency thermocoagulation therapy in primary trigeminal neuralgia

Our objective was to observe and document cardiovascular side effects of radiofrequency thermocoagulation of the trigeminal ganglion. Forty-eight patients with primary trigeminal neuralgia were enrolled into this study. Continuous electrocardiogram, heart rate, cardiac rhythm changes, and systemic blood pressure were monitored during the procedure of oval foramen puncture, electrode needle stimulation, and lesion production. Oval foramen puncture led to decreases in heart rate in 6 patients, increases in heart rate in another 42 patients, and significant elevation of mean arterial blood pressure in all 48 patients. The frequency (50 Hz) of prelesion electrical stimulation caused slight pressor responses, and radiofrequency thermocoagulation caused marked pressor responses. The correlation between the intensity of the stimulus and the magnitude of the pressor response was positive when temperature during radiofrequency thermocoagulation was below 75 degrees C. That correlation became negative when the temperature exceeded 75 degrees C. We conclude that greater anticipatory awareness should be directed toward pressor than depressor responses during the procedures of percutaneous radiofrequency thermocoagulation therapy in primary trigeminal neuralgia.