Choroid plexus enlargement correlates with cognitive dysfunction and disease progression in Moyamoya disease.

Moyamoya disease (MMD) is a progressive cerebrovascular disorder characterized by chronic steno-occlusive changes of the intracranial carotid circulation. Cognitive decline is increasingly recognized in these patients, even in the absence of overt ischemic events. Reliable neuroimaging markers that capture both disease severity and neurocognitive status are urgently needed to inform clinical decision-making and surgical timing. Given the pivotal role of the choroid plexus in glymphatic clearance and the reported glymphatic impairment in MMD, we hypothesized that choroid plexus volume (CPV) would be increased in MMD patients and associated with both cognitive performance and angiographic severity.In this prospective study, 41 newly diagnosed adult MMD patients and 19 demographically matched healthy controls underwent high-resolution structural MRI and standardized neuropsychological testing. CPV was segmented, normalized to intracranial volume (ICV), and correlated with cognitive performance. Disease severity was staged using magnetic resonance angiography (MRA).CPV was significantly increased in MMD patients compared with controls (1.42 ± 0.39 vs. 1.18 ± 0.30; p = 0.021). Larger CPV was associated with worse working memory (r = -0.298; p = 0.021) and impaired calculation ability (r = -0.282; p= 0.029). Moreover, CPV was positively correlated with more advanced bilateral MRA stages, suggesting that choroid plexus enlargement parallels disease progression.Choroid plexus enlargement reflects both neurocognitive dysfunction and angiographic severity in MMD. As a potential imaging biomarker, CPV may complement conventional vascular assessment, facilitate early risk stratification, and support neurosurgical treatment planning.