Diffusion tensor imaging analysis along the perivascular space derived intracerebral glymphatic system circulatory function on neuromyelitis optica spectrum disorder: a follow-up study for curative effect / 中华放射学杂志

ABSTRACT

Objective:To evaluate the value of curative effect in neuromyelitis spectrum disease (NMOSD) based on circulatory function evaluation of intracerebral glymphatic system by using diffusion tensor imaging analysis along the perivascular space.Methods:The clinical and imaging data of 23 patients diagnosed with NMOSD at Tianjin Medical University General Hospital from March 2018 to December 2019 were retrospectively analyzed in this study. The clinical data included expanded disability status scale (EDSS), average relapse rate (ARR) and retinal nerve fiber layer (RNFL) thickness at baseline and 1 year follow-up after treatment. Among the 23 NMOSD patients, there were 22 females and 1 male, aged from 21 to 71 (45±13) years old. All the patients underwent MR scans at both baseline and 1 year after treatment, and the scanning sequences included cerebral 3D-T 1WI, T 2WI, diffusion tensor imaging and cervical spinal sagittal 3D-T 2WI, and the cervical spinal cord volume and bilateral diffusion tensor imaging analysis along the perivascular space index (ALPS index) were calculated. The partial correlation test was used to analyze the correlations between ALPS index and the clinical indicators such as EDSS, ARR, and bilateral RNFL, with the control variables as gender, age, years of education and course of disease. The multiple linear regression model was used to analyze the independent predictors for ALPS index and EDSS after treatment. Receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to evaluate the diagnostic value of NMOSD treatment outcome by using ALPS index. Results:When controlling for gender, age, years of education and course of disease, there were significant negative correlations between right ALPS index and EDSS ( r=-0.50, P=0.048), bilateral average ALPS index and EDSS ( r=-0.53, P=0.034), left ALPS index and ARR ( r=-0.58, P=0.018), while there was significant positive correlations between right ALPS index and RNFL ( r=0.88, P=0.008) at 1 year follow-up after treatment. Multiple linear regression analysis showed that cervical spinal cord volume was an independent impact factor of bilateral average ALPS indexes (β=0.24, 95%CI 0.10-0.38, P=0.002), and bilateral average ALPS indexes (β=-3.22, 95%CI -5.97--0.48, P=0.024) and right RNFL (β=-0.05, 95%CI -0.08--0.02, P=0.002) at baseline were the independent impact factors of EDSS after treatment. ROC curve analysis showed that the bilateral average ALPS index at baseline had the best efficacy in predicting the curative effect of NMOSD patients with AUC=0.92. Conclusions:After treatment, NMOSD patients with severe clinical disability, high frequency of disease attack, poor visual performance, and severe cervical spinal cord atrophy have more serious impairment of intracerebral glymphatic system circulatory function. The ALPS index could help in predicting the clinical curative effect of NMOSD patients.