ABSTRACT
A 44-year-old man was referred to the emergency department by his ophthalmologist because of persistent drooping and swelling of his right eyelid. Horner syndrome was diagnosed. Horner syndrome refers to a constellation of signs produced when sympathetic innervations to the eye are interrupted. Horner syndrome is a rare condition that affects the nerves to the eye and face. Symptoms included decreased sweating on the affected side of the face, drooping eyelid (ptosis), sinking of the eyeball into the face, and constricted pupil. Although Horner syndrome is commonly an incidental finding related to a benign cause, it occasionally may be a manifestation of a serious and life-threatening disorder, such as carotid artery dissections (CAD). Careful direction of the history to rule out life-threatening disorders is of the utmost importance for advanced practice nurses in the emergency department. Carotid artery dissection is increasingly recognized as a cause of morbidity and mortality. A case of CAD following sinusitis in a patient with Horner syndrome is described. The causes, management, and outcomes of CAD are discussed herein.