Aberrant innervation of the sternocleidomastoid muscle by the transverse cervical nerve: a case report.

Two aberrant rami originating from the right transverse cervical nerve and innervated the midportion of the sternocleidomastoid muscle (SM) were detected during routine cadaver dissection. Although SM is commonly innervated by the accessory nerve, as well as by cervical nerves, it is likely to be innervated additionally by other nerves such as hypoglossal nerve, ansa cervicalis, facial or external laryngeal nerve. Some considerations as regards the possible composition of the aberrant rami of the transverse cervical nerve detected in the current study, as well as the relevant literature is discussed.