Communication between the superior cervical sympathetic ganglion and the inferior laryngeal nerve.

Complex arborisations occurs between the inferior ganglion of the vagus nerve and the superior cervical sympathetic ganglion (Braeucker, 1923; Fick, 1926; Siwe, 1931; Hoffman, 1957). The superior cervical sympathetic ganglion sends branches to the internal and the external carotid arteries, the inferior vagal ganglion, the superior laryngeal nerve and the cervical nerves, and provides superior cardiac and thyroid branches as well as the trunk that descends directly to the middle and inferior cervical sympathetic ganglia. There are communications between the vagus nerve (laryngeal branches) and the superior cervical sympathetic ganglion (SCSG). Cannizzaro et al. (1991) and Zerilli et al. (1994) reported abnormalities of sympathetic function among the effects of injury to the superior laryngeal nerve during thyroid surgery. The interconnections between these various nerves are therefore of clinical importance. We document here a rare example of complex communication between the vagus nerve and the SCSG in dissections of 113 adult (78 male, 35 female) Japanese cadavers. Both sides were examined in 88 cases, the right only in 18 and the left only in 7 (i.e. 201 sides in total).