Abnormal neurite orientation dispersion and density imaging of white matter in children with primary nocturnal enuresis

Several lines of evidence indicate that multiple abnormalities of gray matter are related to the pathogenesis of primary nocturnal enuresis (PNE); however, few studies have been conducted with respect to abnormalities in white matter (WM) of children with PNE. The present work investigated the microstructure of WM in children with PNE using a neurite orientation dispersion and density imaging (NODDI) method. NODDI data were obtained from 29 children with PNE (age = 9.8 ± 1.2 years, 59% males) and 34 healthy controls (age = 10.3 ± 1.6 years, 56% males) in this study. Multi-b-value diffusion-weighted imaging data were acquired with a 3 T MR system, and the orientation dispersion index (ODI) and neurite density index (NDI) maps were calculated. Tract-Based Spatial Statistics analyses of WM tracts were performed with ODI and NDI maps in children with PNE and controls. Children with PNE had lower ODIs in WM fiber tracts of the bilateral superior longitudinal fasciculus (SLF) and higher ODIs in the bilateral internal capsule (IC) and right anterior thalamic radiation (ATR) than controls. PNE children also had lower NDIs in the bilateral IC and the cingulum and higher NDIs in the bilateral SLF. These changes in NODDI indices, which indicated abnormal neural maturation of the WM microstructures, may be related to abnormal sleep and enuresis in children with PNE.