Horner's Syndrome Associated with Spontaneous Dissection of the Internal Carotid Artery

A Horner's syndrome not associated with other cranial nerve palsies is generally felt not to represent a significant process. The relatively high incidence of a Horner's with cluster headaches is a good example and it is not uncommon for the headache to be atypical. Also it is not unheard of for the Horner's to be persistent. Recent attention has been drawn to the association of head pain, Horner's syndrome and spontaneous dissection of the internal carotid artery. The following case report illustrates this phenomenon.