Background The relationship between anterior cerebral artery (ACA) occlusion and moyamoya disease (MMD) has rarely been studied. In this study, we focused on a special type of MMD: isolated ACA-occlusive MMD. We investigated clinical attributes, genotypes and progression risk factors in patients with ACA-occlusive MMD, providing initial insights into the relationship between ACA occlusion and MMD. Methods We retrospectively analysed digital subtraction angiography (DSA) from 2486 patients and diagnosed 139 patients with ACA-occlusive MMD. RNF213 p.R4810K (rs112735431) mutation analysis was performed. Patients were categorised into progression and non-progression groups based on whether they progressed to typical MMD. Differences in clinical characteristics, neuropsychological assessment, radiological findings and genotypes were evaluated. Logistic regression analyses identified risk factors for ACA-occlusive MMD progression. Results The median age of patients with ACA-occlusive MMD was 36 years, and the primary symptom was transient ischaemic attack (TIA). 72.3% of ACA-occlusive MMD patients had cognitive decline. Of 116 patients who underwent RNF213 gene mutation analysis, 90 patients (77.6%) carried the RNF213 p.R4810K GG allele and 26 (22.4%) carried the GA allele. Of 102 patients with follow-up DSA data, 40 patients (39.2%) progressed. Kaplan-Meier curve estimates indicated a higher incidence of ischaemic stroke in the progression group during follow-up (p=0.035). Younger age (p=0.041), RNF213 p.R4810K GA genotype (p=0.037) and poor collateral compensation from the middle cerebral artery (MCA) to ACA (p<0.001) were risk factors of ACA-occlusive MMD progression to typical MMD. Conclusions Cognitive decline and TIA might be the main manifestations of ACA-occlusive MMD. Isolated ACA occlusion may be an early signal of MMD. The initial lesion site of MMD is not strictly confined to the terminal portion of the internal carotid artery. Younger patients, patients with RNF213 p.R4810K GA genotype or those with inadequate MCA-to-ACA compensation are more likely to develop typical MMD. Data are available upon reasonable request.

中文翻译：

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孤立性大脑前动脉闭塞：烟雾病的一种非典型形式

背景 大脑前动脉（ACA）闭塞与烟雾病（MMD）之间的关系很少被研究。在这项研究中，我们关注一种特殊类型的 MMD：孤立性 ACA 闭塞性 MMD。我们调查了 ACA 闭塞性 MMD 患者的临床特征、基因型和进展危险因素，为 ACA 闭塞与 MMD 之间的关系提供了初步见解。方法 我们回顾性分析了 2486 例患者的数字减影血管造影 (DSA)，诊断出 139 例 ACA 闭塞性 MMD 患者。进行 RNF213 p.R4810K (rs112735431) 突变分析。根据患者是否进展为典型的MMD，将其分为进展组和未进展组。评估了临床特征、神经心理学评估、放射学结果和基因型的差异。逻辑回归分析确定了 ACA 闭塞性 MMD 进展的危险因素。结果 ACA闭塞性MMD患者中位年龄为36岁，主要症状为短暂性脑缺血发作（TIA）。72.3% ACA 闭塞性 MMD 患者出现认知能力下降。在接受 RNF213 基因突变分析的 116 名患者中，90 名患者（77.6%）携带 RNF213 p.R4810K GG 等位基因，26 名患者（22.4%）携带 GA 等位基因。在 102 名有 DSA 随访数据的患者中，40 名患者 (39.2%) 出现进展。Kaplan-Meier 曲线估计表明，随访期间进展组缺血性卒中的发生率较高 (p=0.035)。年龄较小（p=0.041）、RNF213 p.R4810K GA 基因型（p=0.037）和大脑中动脉（MCA）至 ACA 的侧支代偿不良（p<0.001）是 ACA 闭塞性 MMD 进展为典型 MMD 的危险因素。结论认知能力下降和TIA可能是ACA闭塞性MMD的主要表现。孤立的 ACA 闭塞可能是 MMD 的早期信号。MMD的起始病变部位并不严格局限于颈内动脉的末端部分。年轻患者、RNF213 p.R4810K GA 基因型患者或 MCA 至 ACA 代偿不足的患者更有可能出现典型的 MMD。数据可根据合理要求提供。