Surgical Interventions Targeting the Nucleus Caudalis for Craniofacial Pain: A Systematic and Historical Review

Craniofacial pain is a prevalent group of conditions, and when refractory to conventional treatments, it poses a significant burden. The last decade has seen a renewed interest in the multimodal management of pain. Interventions targeting the nucleus caudalis (NC) of the trigeminocervical complex have been available as a treatment option since the 1930s, yet evidence for efficacy remains limited.

We present a systematic review of the literature providing a historical perspective on interventions targeting the NC leading up to the present. We examine the various intervention techniques, clinical indications, and procedural efficacy. A novel outcome-reporting scheme was devised to enable comparison among studies owing to historically variable reporting methods.

A review of the literature revealed 33 retrospective studies published over the last 80 years, reporting on 827 patients. The most common technique was the open NC dorsal root entry zone nucleotomy/tractotomy; however, there has been an emergence of novel approaches such as endoscopic and spinal cord stimulation in the last ten years. Regardless of intervention technique or preoperative diagnosis, 87% of patients showed improvement with treatment.

The literature surrounding NC intervention techniques is reviewed. Recent advancements and the wide range of craniofacial pain syndromes for which these interventions show potential efficacy are discussed. New and less invasive techniques continue to emerge as putative therapeutic options. However, prospective studies are lacking. Furthermore, the evidence supporting even well-established techniques remains of poor quality. Future work should be prospective, use standard outcome reporting, and address efficacy comparisons between intervention type and preoperative diagnosis.