The cervical sympathetic nerves in surgery of the neck

The otolaryngologist-head and neck surgeon is aware that the cervical sympathetic nerves lie behind the carotid artery and should be avoided during neck surgery. To render this sketchy dictum more tangible, relevant anatomy and physiology of the autonomic supply to the head and neck is reviewed, as are aspects of site-of-lesion testing, with respect to Horner's syndrome. Examples of neck operations during which the cervical sympathetic chain--from the base of skull to the root of the neck--may be injured are illustrated.