Cervical plexus as anatomical target for the treatment of postoperative cervical neuropathic pain

Abstract

Objective: The incidence of chronic neuropathic pain following neck dissections is approximately 40%. Standard drug therapy in these patients include pharmacologic treatments due to the neuropathic pain (gabapentinoids, tricyclic antidepressants...). In this case, standard options were limited. The addition of ultrasound guidance to invasive pain management techniques has enabled us to successfully treat pathologies in which previous treatments options had been limited. Pulsed radiofrequency (PRF) ablation permits treatment over nerve structures that, due to either their morphological or functional characteristics, could not be approached using the conventional variant. Case report: A 45-year-old man with severe postoperative pain after undergoing partial glossectomy and functional neck dissection for squamous cell carcinoma of the tongue. The patient had been treated pharmacologically for several years with minimal results, baseline VAS of 90. After a successful superficial cervical plexus block under ultrasound guidance, he underwent PRF for a possible long-lasting effect. VAS post PRF improved in subsequent visits: VAS at 1 month was 0; at 3 months was 10 and at 6 months was 60. Conclusion: Postoperative changes to include alterations in nerve structures are a frequent source of chronic pain. The incidence of this type of pain in the cervical region is quite variable. Noninvasive treatment options are limited and oftentimes ineffective. Due to its location, superficial cervical plexus is an anatomical site with the potential risk of undergoing structural alterations (fibrosis, radiotherapy-associated retraction phenomena or neuroma formation). Interventional treatments performed under ultrasound guidance allow the dynamic application of therapies such as radiofrequency ablation. PRF could potentially cause an additive effect between neuromodulation and the hydrodissection caused by the infiltration of substances within a fibrotic area.