Teaching Neuro Images : Rare cause of Horner syndrome in Loeys-Dietz syndrome

A 36-year-old woman with Loeys-Dietz syndrome presented with left eye ptosis, anisocoria, and shoulder pain. The diagnosis of left-sided Horner syndrome was made (figure 1). The patient had a known left subclavian artery aneurysm with percutaneous stent graft placement. CT angiography revealed a large left subclavian aneurysm sac, consistent with endoleak type I (figure 2). Horner syndrome and shoulder pain improved following common carotid to axillary artery bypass in addition to thoracic endovascular aortic repair surgery.