Orbital apex syndrome from middle meningeal artery embolization.

PURPOSE: To present two cases of orbital apex syndrome, a previously unreported complication of middle meningeal artery (MMA) embolization. BACKGROUND: MMA embolization is increasingly used to treat chronic subdural hematomas and is generally considered safe. However, anastomotic connections to the ophthalmic circulation may permit complications from embolic migration. METHODS: Retrospective case series of two patients who developed neuro-ophthalmic complications following MMA embolization for subdural hematoma. RESULTS: A 75-year-old male developed acute diplopia, a relative afferent pupillary defect (RAPD), and ophthalmoplegia shortly after MMA embolization. Magnetic resonance imaging demonstrated embolic material in the posterior orbit. He was diagnosed with an orbital apex syndrome and treated with intravenous steroids with improvement in ocular motility and alignment and resolution of his RAPD. A 44-year-old male presented 1 year after MMA embolization with progressive diplopia, ptosis, and visual loss. Examination revealed an optic neuropathy, and multiple cranial neuropathies consistent with an orbital apex syndrome. He was treated with oral steroids and had improvement in his vision and oculomotor examination. CONCLUSIONS: Case reports of ophthalmic complications from MMA embolization have reported transient cranial neuropathies or isolated ischemic events, presumably through unintended migration of embolic material through under-recognized meningo-ophthalmic anastomoses. These cases are the first report of orbital apex syndrome as a potential complication of MMA embolization.