Horner’s syndrome Home A-Z Health Information Health Library A-Z Horner’s Syndrome Overview Horner’s syndrome is a rare type of oculosympathetic nerve palsy wherein the sympathetic nerves that control the eyes and face are damaged. Causes Lesion of the primary neuronLesion of the postganglionic neuronTrauma to the brachial plexusBrainstem tumour, stroke, syrinx of the preganglionic neuronCarotid artery ischemiaTumours (e.g. Pancoast) or infection of the lung apexDissecting carotid aneurysmInternal jugular vein catheterizationMiddle cranial fossa neoplasmMigraine Risk factors Trauma to the neck or head, or damage to the nerves or carotid artery during birth or surgeryBenign or malignant tumours in the lungs, thyroid, hypothalamus, or cervical nerves Middle ear infections or other infections Stroke, aneurysm, embolism, or carotid artery dissectionMigraines or cluster headachesFamily historyMultiple sclerosis or other diseases that affect the protective covering of neurons Symptoms Small sized pupilEye retractionDrooping of eye lid or elevation of lower eyelidDecreased sweating over side of face affectedPallor of side of face affected Specialist to approach Neurologist Treatment Treatment of underlying conditionNo specific cure