Surgically treated cerebral arterial ectasia with so-called moyamoya vessels.

The case of a 43-year-old woman with multiple intracranial arterial ectasia was reported. The arterial ectasia was accompanied by stenosis of the middle cerebral artery and so-called moyamoya vessels. After extracranial to intracranial bypass surgery, the size and contour of the arterial ectasia decreased. Because the arterial ectasia decreased in size after the extracranial to intracranial bypass surgery, this operation might be useful for space-occupying lesions due to arterial ectasia.