Validity of percutaneous controlled radiofrequency thermocoagulation in the treatment of isolated third division trigeminal neuralgia.

Background: Of 756 percutaneous controlled radiofrequency thermocoagulations of gasserian ganglion and/or retrogasserian rootlets for idiopathic trigeminal neuralgia or for trigeminal neuralgia in multiple sclerosis, the results in 158 patients who had isolated third division trigeminal neuralgia were reviewed.

Methods: In 129 patients, percutaneous thermocoagulation was fluoroscopic guided, whereas in the last 29 the procedure was performed under CT control. In all cases, the goal was to achieve selective anesthesia limited to the third trigeminal division.

Results: Complete pain relief was obtained immediately after the procedure in all patients and selective anesthesia in the third division was achieved in all of them, except for 2 patients in whom unwanted first and second division anesthesia/hypoesthesia also occurred. Other significant complications were transient sixth cranial nerve palsy in 1 patient and masseter muscle dysfunction, which improved during follow-up, in another one. The selected sensory impairment was well tolerated in all patients. During an average follow-up period of 8.8 years, recurrences occurred in 12 patients, together with a partial regression of the anesthesia: in 10 patients the procedure was repeated successfully. In 2 patients with multiple sclerosis, the procedure was repeated twice and 3 times, respectively.

Conclusions: Percutaneous controlled radiofrequency thermocoagulation is quite easy to perform under fluoroscopic or CT control, and it involves no mortality and very low morbidity; it is an immediately effective procedure and the rate of recurrence is low. Last, but not least, if the anesthesia is limited to the third division, no anesthesia dolorosa occurs and patients are very grateful.