Glymphatic System Impairment in the Advanced Stage of Moyamoya Disease

ABSTRACT Assessing the glymphatic system activity using diffusion tensor imaging analysis along with the perivascular space (DTI‐ALPS) may be helpful to understand the pathophysiology of moyamoya disease (MMD). 63 adult patients with MMD and 20 healthy controls (HCs) were included for T1‐weighted images, T2‐FLAIR, pseudocontinuous arterial spin labeling, and DTI. 60 patients had digital subtraction angiography more than 6 months after combined revascularization. The Suzuki stage, postoperative Matsushima grade, periventricular anastomoses (PA), enlarged perivascular spaces (EPVS), deep and subcortical white matter hyperintensities (DSWMH), DTI‐ALPS, cerebral blood flow (CBF), and cognitive scales of MMD patients were assessed. MMD patients were divided into early and advanced stage based on the Suzuki stage. We detected lower DTI‐ALPS in patients with advanced stage relative to HCs ( p = 0.046) and patients with early stage ( p = 0.004), hemorrhagic MMD compared with ischemic MMD ( p = 0.048), and PA Grade 2 compared with Grade 0 ( p = 0.010). DTI‐ALPS was correlated with the EPVS in basal ganglia ( r = −0.686, p < 0.001), Suzuki stage ( r = −0.465, p < 0.001), DSWMH ( r = −0.423, p = 0.001), and global CBF ( r = 0.300, p = 0.017) and cognitive scores ( r = 0.343, p = 0.018). The DTI‐ALPS of patients with good postoperative collateral formation was higher compared to those with poor postoperative collateral formation ( p = 0.038). In conclusion, the glymphatic system was impaired in advanced MMD patients and may affected cognitive function and postoperative neoangiogenesis.