Child Neurology: Horner Syndrome in an Otherwise Well-Appearing Infant.

We report an exemplary case of acquired Horner syndrome secondary to neuroblastoma in infancy. The patient presented with ptosis, miosis, and heterochromia. In reviewing the patient's laboratory and imaging workup, we highlight key etiologic differences between the pediatric and adult populations. Other important teaching points included in the discussion are a review of sympathetic neuroanatomy and oculosympathetic paresis, the appropriate and evidence-based diagnostic workup in infants and children, and a review of pharmacologic testing using cocaine and apraclonidine drops.