Moyamoya disease in a 12-year-old Caucasian boy presenting with acute transient psychosis

This paper reports the case of a 12-year-old boy who presented with an acut e transient psychosis. Investigations revealed Moyamoya disease with occlus ion of the left middle cerebral artery. There was no previous history of tr ansient ischaemic attacks, no history of psychiatric disease, no family his tory of psychosis and no history of illicit drug use. Although no previous cases of Moyamoya disease with psychosis as the sole presenting feature hav e been described, we suggest the possibility of a causal link.