P.099 A novel electrophysiologic reflex in neurovascular compression syndromes serving as a marker of pain resolution

Abstract

Background: Radiofrequency rhizotomy is a commonly used percutaneous technique for treatment of trigeminal neuralgia especially in cases not eligible for microvascular decompression. This technique is usually performed with the patient under conscious sedation. We devised a method for performance of this technique under general anesthetic with neurophysiology monitoring. Methods: The patient is put under general anaesthetic and EMG monitoring is set up. Needles are placed in temporalis muscle, masseter and mylohyoid or anterior belly of digastric. Resting activityis monitored. Rhizotomy is then performed under fluoroscopic guidance, with monitoring of EMG potentials pre- and post-lesioning, with specific attention paid to presence of an abnormal electrophysiologic reflex. Results: A total of 38 procedures were performed in 23 patients. Of these, 15 were revision procedures. Patients had improvement from BNI pain scale 3.8 ±0.8 to 1.3 ±1.5, and had a reduction in number of medications from 1.9 ±1.0 to 0.8 ±0.9. Survey results indicate greater practitioner satisfaction with this technique. Conclusions: Radiofrequency rhizotomy can be performed under GA with IONM guidance with good results. We present a novel method for EMG-based monitoring. Further study is required to validate this technique.