It is called moyamoya and it an extremely rare genetic condition.
Circle of Willis
Cerebral arterial circle or circle of Willis
Circle of Willis or the cerebral arterial circle
Dontrelle Willis's birth name is Dontrelle Wayne Willis.
Willis Cook's birth name is Willis R. Cook.
Willis Hudlin's birth name is George Willis Hudlin.
Willis Holman's birth name is Willis Leonard Holman.
Willis Bouchey's birth name is Willis Ben Bouchey.
Ellen Willis's birth name is Ellen Jane Willis.
Jerome Willis's birth name is Jerome Barry Willis.
Masi Willis's birth name is Carolyn Mason Willis.
Rayshelle Willis's birth name is Rayshelle D. Willis.