Introduction: moyamoya disease.

This issue of Neurosurgical Focus is devoted to the topic of moyamoya disease/syndrome. When the senior editor (R.M.S.) was a neurosurgical resident in the late 1960s and early 1970s, the condition was virtually unknown in the Western hemisphere, and patients with "cerebrovascular insufficiency" and the typical arterial findings on angiography were believed to have a type of arteritis. The refinement of catheter angiography techniques and the development of the imaging modalities of CT and MR imaging clarified the significance of making the correct diagnosis of moyamoya disease in affected patients, and with the development of direct and then indirect revascularization procedures during this same period, neurosurgeons became involved in the disease's treatment.