[A case of Prader-Willi syndrome with bilateral middle cerebral artery occlusion and moyamoya phenomenon].

We report a case of Prader-Willi syndrome (PWS) complicated with juvenile stroke. The patient is a 19-year-old man with right hemiplegia, who has had a history of non-insulin-dependent diabetes mellitus (NIDDM) for ten years. The diagnosis of PWS was confirmed genetically by the method of fluorescence in situ hybridization which showed the deletion of chromosome 15. His brain MRI revealed abnormal signal intensities in the left basal ganglia and around the right trigone of the lateral ventricle. Angiographic examination showed occlusions of bilateral proximal middle cerebral arteries with basal moyamoya vessels. The left vertebral artery was also occluded at its origin. Only a few cases of PWS complicated with stroke have been reported before and, to date, there has been no case with arterial occlusion similar to our case. Though the cause of these arterial occlusions is unknown, it may be related to arteriosclerosis following NIDDM.