Reading about Moyamoya Disease in the NEJM

I admit, I don't remember learning about moyamoya disease/syndrome in medical school. I must have been asleep during that lecture. The NEJM has a great review article on moyamoya disease and defines it like this: "The moyamoya syndrome is a cerebrovascular condition that predisposes affected patients to stroke in association with progressive stenosis of the intracranial internal carotid arteries and their proximal branches."

Moyamoya can cause strokes in children and adults. I remember treating a teenager who had suffered several strokes. She had no known coagulopathies, so now I wonder if she might have had moyamoya syndrome (I doubt it).