THE SYMPATHETIC-NERVES OF THE PARASELLAR REGION - PATHWAYS TO THE ORBIT AND THE BRAIN

Sympathetic nerves innervate targets in the orbit and the brain. They issue from the superior cervical ganglion and reach the parasellar reg ion via the internal carotid nerve. Information on their further paras ellar course and distribution is scant and contradictory. In this stud y the parasellar sympathetic pathways of 30 human infants and 6 human fetuses were investigated by microdissection and histologically. A com mon parasellar sympathetic trunk, which reunites all the nerve fibers emanating from the lateral and medial internal carotid plexus, is desc ribed as well as its further divisions. It was found that the posterio r knee of the infant carotid siphon is free of large sympathetic nerve bundles. In addition a ganglion is described, which is situated in th e parasellar adipose body. It is reached by nerve fibers coming from t he parasellar sympathetic pathways. Fibers that issue from this gangli on join the periorbita and the orbital muscle of Muller. These anatomi cal facts are of immediate importance for preventing nerve damage duri ng cavernous sinus surgery. Furthermore, the study improves the anatom ical knowledge of the parasellar region and suggests a new concept for the innervation of the orbital muscle.