Glymphatic System Activity May Be Disrupted in Moyamoya Disease : The Diffusion Tensor Image Analysis Along the Perivascular Space (DTI-ALPS) Study [Presidential Award Proceedings]

Abstract

　This study aimed to investigate diffusion along the perivascular space (DTI-ALPS index), which may reflect glymphatic system function in adult patients with moyamoya disease. We evaluated 46 patients with moyamoya disease using multishell diffusion magnetic resonance imaging, perfusion parameters of ¹⁵O-gas positron emission tomography, and cognitive tests. Diffusion data were analyzed to evaluate the DTI-ALPS index and free water parameters of each hemisphere and compared with the DTI-ALPS index of 34 age-sex-matched normal controls. Compared to normal controls, patients with moyamoya disease showed a significantly lower DTI-ALPS index (mean (standard deviation)=1.93 (0.25) vs. 1.64 (0.22) ; p<0.001). The DTI-ALPS index of patients with moyamoya disease was significantly correlated with perfusion parameters (vs. mean transit time, r=0.33), free water parameters (vs. free water fraction created from free water eliminated diffusion tensor imaging of the cortex, r=−0.24), and executive function (vs. trail making test part B, r=−0.47). These results indicate that glymphatic system dysfunction may exist, correlate with the degree of hemodynamic disturbance, lead to increased parenchymal free water, and be related to cognitive dysfunction in adult patients with moyamoya disease.