Sternocleidomastoid innervation from an aberrant nerve arising from the hypoglossal nerve: a prospective study of 160 neck dissections

Abstract

This finding adds to the knowledge of variants in this area. Meticulous dissection and preservation of all nerves, where possible, is important for optimising functional outcomes following surgery.

Postoperative Analgesic Effect of Ultrasound-Guided Intermediate Cervical Plexus Block on Unipolar Sternocleidomastoid Release With Myectomy in Pediatric Patients With Congenital Muscular Torticollis

“…The cervical plexus (C2-C4) supplies sensation to the sternocleidomastoid muscle, including proprioception, and has variable anastomosis with the spinal accessory nerve at the posterior surface or inside of the sternocleidomastoid muscle. [12][13][14]25 The accessory nerve To ensure effective blockade of the sensory branches of the cervical plexus supplying the lower portion of the sternocleidomastoid muscle, and the corresponding skin and platysma muscle, unlike the carotid endarterectomy, we attempted to maintain the injection at the C4-C5 level, because the cervical plexus is situated between the longus capitis and middle scalene muscles. 28 If the injection were to be made at a level higher than C4, it would be possible to spare the lower cutaneous branches of the cervical plexus-the transverse cervical and supraclavicular nerves-in the PCS, 29 especially when using a small volume of local anesthetic.…”

“…[9][10][11] Sensory innervation of the sternocleidomastoid muscle, including proprioception, arises from C2-C4 cervical spinal nerves. [12][13][14] Accordingly, we hypothesized that an ultrasound-guided (USG) intermediate cervical plexus block (CPB), which targets the posterior cervical space (PCS)between the sternocleidomastoid muscle and prevertebral fascia-as Choquet et al 15 suggested, would effectively treat post-USRM pain associated with both skin incision and sternocleidomastoid muscle resection. The objective of this study was to examine the effect of USG intermediate CPB on postoperative pain after USRM.…”

Cervical plexus block

“…In contrast, the fibers emanating anteromedially from the superior (C1–C2) and inferior (C2–C3) roots unite at the level of the omohyoid central tendon to form a loop, the ansa cervicalis [ 47 ]. The ansa cervicalis is known to supply motor branches to the infrahyoid and SCM muscles [ 48 ] with a great degree of variation in its origin and distribution [ 49 ]; however, ansa cervicalis has been suspected to have an afferent neuronal composite [ 50 ]. The anterior rami of C3 and C4 form a loop and the branches of this loop join C5 to give rise to the phrenic nerve.…”

Variation of the sternocleidomastoid muscle: a case report of three heads and an accessory head

“…Therefore, the innervation of SCM and trapezius shares the accessory nerve. In present case, the innervation of additional head was accessory nerve, however, previous study showed that the hypoglossal nerve innervated SCM in 2.5% of 160 neck [1]. Therefore, an association between variant innervation and additional head of SCM should be studied further.…”