Horner's syndrome.(NEURO-OPHTHALMIC DISEASE)(Pathophysiology)(Disease/Disorder overview)

Signs and Symptoms

Horner's syndrome is characterized by an interruption of the oculosympathetic nerve supply somewhere between its origin (in the hypothalamus) and the eye. (1-9) The classic clinical findings associated with Horner's syndrome are ptosis, pupillary miosis, facial anhidrosis, apparent enophthalmos, increased amplitude of accommodation, heterochromia of the irides (if congenital or occurring before the age of two years), paradoxical contralateral eyelid retraction, transient decrease in intraocular pressure and changes in tear viscosity. (1-9) Horner's syndrome has no predilection for age, race, gender or geographic location. Horner's syndromes of congenital origin present around age two, with heterochromia and absence of a horizontal eyelid fold or crease in the ptotic eye. (1-5,9) Iris pigmentation (which is under sympathetic control during development) is completed by this age, making heterochromia an uncommon finding in Horner's syndromes acquired later in life. (1-3) Old photographs can aide the clinician in distinguishing congenital Horner's by documenting heterochromia present at birth. (1-5)

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Pathophysiology

Sympathetic innervation to the eye consists of a three-neuron arc. (1-9) The first neuron originates in the dorsolateral hypothalamus. It descends through the reticular formation of the brain stem and travels to the ciliospinal center of Budge, between the levels of the eighth cervical and fourth thoracic vertebrae (C8-T4) of the spinal cord. There, it synapses with second-order neurons whose preganglionic cell bodies give rise to …