‘Angiographic Moyamoyaʹ its definition, classification, and therapy

Are there any differences between probable Moyamoya disease and unilateral Moyamoya disease? What kinds of differences exist between definite and probable Moyamoya disease? Furthermore, according to the diagnostic criteria of Moyamoya disease, patients with systemic disorders and angiographic features similar to those of Moyamoya disease can not be diagnosed as Moyamoya disease. How should we call these? Such patients have been reported as ‘Moyamoya syndrome,ʹ ‘quasi-Moyamoya diseaseʹ, ‘akin-Moyamoya diseaseʹ, etc. These variations of terminology including unilateral or probable Moyamoya disease have thus led to as state of confusion. In this study the previously reported cases in the literature were surveyed to clarify how these terms have been used and how we should use them correctly in the future. Since the diagnostic criteria of this disease are mainly based on angiographic findings, the term Moyamoya ‘syndromeʹ should not be used. A unilateral involvement without any known cause should be called ‘probable.ʹ Because some systemic diseases commonly associated with Moyamoya disease might be genetically linked, it is better to avoid using such vague expressions as ‘quasiʹ, ‘akinʹ, or ‘pseudo.ʹ There might be a coexistence of two diseases. It is therefore better to simply state that the angiographic findings are similar to Moyamoya disease, or a systemic disease with ‘angiographic Moyamoyaʹ until the etiology of the Moyamoya disease is clarified.