Pseudo-Horner Syndrome in Infancy

Abstract

A 2-month-old girl presented with ptosis of the right upper and lower eyelids, mild miosis (without dilation lag) of the right pupil, and apparent enophthalmos of the right eye (Fig A). Concern for Horner syndrome led to magnetic resonance imaging (MRI) of the head, neck, and chest, with MRI angiography of the head and neck (all interpreted as normal). Later review of axial orbital MRI showed enophthalmos of the right eye with greater kinking of the right optic nerve (Fig B). Horner syndrome is known to produce apparent enophthalmos.