Moyamoya Disease among Young Patients: Its Aggressive Clinical Course and the Role of Active Surgical Treatment

The prognosis for moyamoya disease (MMD) among young patients is known to be worse than that among older patients. The aim of this study was to investigate the clinical features and treatment outcomes of young patients with MMD.A total of 204 patients with MMD who underwent encephaloduroarteriosynangiosis, with or without bifrontal encephalogaleosynangiosis, were categorized into three groups according to their ages at the time of surgery, i.e., Group A (n = 23, <3 yr of age), Group B (n = 50, 3-6 yr of age), and Group C (n = 131, >6 yr of age). For each group, patterns of presentation and the occurrence of subsequent preoperative or surgery-related infarctions were assessed. Clinical outcomes and postoperative hemodynamic status were analyzed.At initial presentation, infarctions were significantly more frequent in Group A (87%) and Group B (58%) than in Group C (46%). Subsequent preoperative infarctions occurred significantly more frequently in Group A (39%) than in Group B (6%) or Group C (0.8%). The median interval between the onset of symptoms and a subsequent preoperative infarction was 3 months (range, 1-14 mo). No significant difference in the rates of surgery-related infarctions among the three groups was observed. The rate of favorable clinical outcomes was significantly lower in Group A (58%) than in Group B (84%) or Group C (86%), although the rates of postoperative hemodynamic improvements were similar among the groups. The poor clinical outcomes for Group A were caused mainly by preoperative infarctions.Young-age MMD demonstrates rapid disease progression and results in poor clinical outcomes. These findings indicate the necessity of early surgery for young patients with MMD; however, the actual benefits should be verified with additional controlled studies, with long-term follow-up monitoring.