Traumatic ptosis and mydriasis masking Horner syndrome from an internal carotid pseudoaneurysm.

A 46-year-old woman presented after blunt facial trauma for evaluation of bilateral orbital floor fractures, which were confirmed by clinical and radiographic examination. In addition, findings of right traumatic mydriasis and left traumatic ptosis were seen. On close investigation, miosis was noted on the side of the traumatic ptosis. Therefore, a workup for Horner syndrome was obtained, including neuro-ophthalmic consultation and magnetic resonance angiography of the neck. The magnetic resonance angiography showed an internal carotid pseudoaneurysm, an uncommon but potentially fatal complication of blunt carotid injury. The authors describe an interesting case where a life-threatening diagnosis was nearly masked by more common, benign pathology.