[Severity Classification of Moyamoya Disease].

Moyamoya disease is currently classified as one of the "Specified Intractable Diseases" by the Ministry of Health, Labor, and Welfare. Since the establishment of this classification in 2014, individuals with mild or nonpersistent symptoms or patients who underwent bypass surgery more than 5 years ago are no longer eligible for certification. To address this issue, the Moyamoya Disease Research Group, under the Ministry of Health, Labor, and Welfare, initiated a revision of the severity criteria in 2021; official revision was passed in 2024. The main change in the revision is the "shift from focusing on fixed symptoms to prioritizing future medical needs."