Sudden cortical blindness in an adult with moyamoya disease

Backgound: We report a case of an adult with MMD who presented initially with left visual field defect that had suddenly progressed to bilateral cortical blindness 1 year and 9 months later. Case Description: A 33-year-old male presented with visual blurring and mild right hemiparesis that developed suddenly. He was regarded as having MMD based on an imaging study. An inverted encephalodurogaleosynangiosis using the left occipital artery and inverted encephaloduroarteriogaleosynangiosis with the parietal branch of the superficial temporal artery were done. The postoperative course was uneventful and without any complication. Several months later, he visited again because of sudden bilateral blindness preceded by repeated transient blindness in both eyes for 4 days. The right posterior temporal artery, which was well visualized at the time of the first postoperative follow-up angiography, was no longer seen on repeated 4-vessel angiography. Biochemical analysis including prothrombin and thrombin time, activated partial thromboplastin time, fibrinogen, d-dimer, plasminogen, antithrombin, platelet, protein C and S, lupus anticoagulant, and cardiolipin antibodies; VDRL was within the reference range. Conclusion: The authors suggest abnormal thromboembolism as a presumed mechanism of the pathogenesis of MMD in this patient.