1295. Congenital Horner Syndrome Associated With Ipsilateral Internal Carotid Artery Hypoplasia

Authors: Muhammad Burhan Ud Din Janjua, MD; Brett Whittemore, MD (Dallas, TX)

Introduction: Horner syndrome is a rare presentation in pediatrics with an incidence estimated at 1.4 per 100,000 patients. This pathology presents with symptoms and signs of miosis, ptosis, facial anhidrosis/hyperemia, and iris heterochromia. The diagnosis is clinical, however, the authors present an imaging correlate: congenital hypoplasia of the ipsilateral internal carotid artery. Methods: The authors describe a case of congenital Horner syndrome along with a literature review with a focus on etiology and relevant imaging. Results: A 15-month-old girl presented to neurosurgical attention for evaluation of asymptomatic cerebellar tonsillar ectopia discovered on MRI performed in workup of pupillary miosis and mild ipsilateral ptosis. She also had iris heterochromia. While the diagnosis of congenital Horner syndrome was based on clinical examination, MRI/MRA with angiographic sequences demonstrated ipsilateral hypoplasia of internal carotid artery and vascular territory supplied by circle of Willis collaterals without evidence of prior congenital infarct. Conclusion: Detailed MR imaging demonstrating hypoplasia of the ipsilateral internal carotid artery suggests an association between dysgenesis of the oculosympathetic pathway in a pediatric patient presenting with congenital Horner syndrome.