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
Willis Cook's birth name is Willis R. Cook.
Caylee Willis's birth name is Caylee Lynn Willis.
Dontrelle Willis's birth name is Dontrelle Wayne Willis.
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.
Rumer Willis's birth name is Rumer Glenn Willis.
Willis Bouchey's birth name is Willis Ben Bouchey.