Surgical interventions targeting the nucleus caudalis for craniofacial pain: a systematic and historical review

Abstract

Introduction: Chronic facial pain is a prevalent group of conditions and when refractory to common treatments poses a social and economic burden. The last decade has seen a multitude of advancements in the multimodal management of pain. Ablative or neuromodulatory interventions targeting the nucleus caudalis (NC) of the trigeminocervical complex is one such treatment that has remained underutilized. Methods: Here we present a systematic review of the literature and historical perspective regarding interventions targeting the NC. We examine the various intervention techniques, clinical indications, and procedural efficacy. A novel outcome reporting scheme was devised to allow comparison between studies using differing outcome reporting methods. Results: A review of the literature revealed 49 retrospective studies published over the last 80 years, reporting on 858 patients. The most common technique was the open NC dorsal root entry zone nucleotomy/tractotomy (n=515, 60.0%); however, there has been an emergence of novel approaches such as endoscopic (n=6, 0.7%) and spinal cord stimulation (n=20, 2.3%) in the last 10 years. Regardless of intervention technique or preoperative diagnosis, 90.4% of patients demonstrated some improvement from treatment. Conclusion: This systematic review highlights recent advancements in NC intervention technique and the wide range of facial pain syndromes for which these interventions show promising efficacy. New and less invasive techniques continue to emerge, however prospective studies remain absent in the literature. Future work should address efficacy comparisons between intervention type and preoperative diagnosis.