This is a single-arm physiology study. Consenting patients undergoing neck dissection (ND) for cervical lymphadenectomy of level IV will undergo dissection of the ansa cervicalis nerves to the infrahyoid strap muscles. Per routine care, a large incision is made across the neck to provide surgeons access to the cervical lymph nodes for extirpation. During this dissection, the branch(es) of the ansa cervicalis nerve plexus descending from the loop of the plexus and innervating the infrahyoid strap muscles (the common trunk) are dissected uni- or bilaterally. For this study, measurements and photos/videos of the common trunks will be taken. An electrode will be placed on one or both common trunks to stimulate infrahyoid muscles.
Recently published data suggest that stimulation of the infrahyoid strap muscles increases pharyngeal patency in patients with obstructive sleep apnea, but the innervation of these muscles by the ansa cervicalis is variable. The investigators propose a study examining the anatomic variation of the ansa cervicalis and the effect of neurostimulation on muscle recruitment.