Microstructural white matter abnormalities in multiple sclerosis and neuromyelitis optica spectrum disorders: Evaluation by advanced diffusion imaging

• Published in: Journal of the neurological sciences Vol. 436; p. 120205
• Main Authors: Kato, Shimpei, Hagiwara, Akifumi, Yokoyama, Kazumasa, Andica, Christina, Tomizawa, Yuji, Hoshino, Yasunobu, Uchida, Wataru, Nishimura, Yuma, Fujita, Shohei, Kamagata, Koji, Hori, Masaaki, Hattori, Nobutaka, Abe, Osamu, Aoki, Shigeki
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-05-2022
• Subjects: Diffusion tensor imaging; Diffusion Tensor Imaging - methods; Free water imaging; Humans; Leukoaraiosis; Multiple sclerosis; Multiple Sclerosis - pathology; Multiple Sclerosis, Relapsing-Remitting - diagnostic imaging; Multiple Sclerosis, Relapsing-Remitting - pathology; Neurite orientation dispersion and density imaging; Neuromyelitis Optica - diagnostic imaging; Neuromyelitis Optica - pathology; Neuromyelitis optica spectrum disorders; Tract-based spatial statistics; Water; White Matter - diagnostic imaging; White Matter - pathology; RRMS; FW; Multiple sclerosis; Tract-based spatial statistics; DTI; NODDI; TBSS; Neurite orientation dispersion and density imaging; Neuromyelitis optica spectrum disorders; Free water imaging; NMOSD; Diffusion tensor imaging
• ISSN: 0022-510X; 1878-5883
• DOI: 10.1016/j.jns.2022.120205

Despite differences in the pathogenesis and treatment of multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), it remains difficult to distinguish them. In this study, we aimed to discriminate between MS and NMOSD using diffusion tensor imaging (DTI), free water (FW) imaging, and neurite orientation dispersion and density imaging (NODDI).
Thirty patients with relapsing-remitting (RR) MS, 18 NMOSD patients with positive anti-aquaporin-4 immunoglobulin G seroreactivity, and 20 age- and sex- matched currently healthy subjects underwent MRI. The differences in the DTI (fractional anisotropy [FA], axial diffusivity [AD], mean diffusivity [MD], and radial diffusivity [RD]), FW and FW-corrected DTI, and NODDI indices between the three groups were evaluated using tract-based spatial statistics (TBSS) and region-of-interest (ROI) analyses.
The ROI analysis of lesions indicated that the RRMS group had significantly higher AD, MD, RD, ISO and FW-corrected AD, and MD; and lower intracellular volume fraction (ICVF) than the NMOSD group. TBSS analysis showed increased water content in RRMS patients compared to NMOSD patients. Compared with healthy controls (HCs) using TBSS and ROI analysis, the changes in FW imaging indices were more limited than those of in DTI in RRMS patients.
FW imaging and NODDI were useful for identifying the etiology of neurodegeneration- and neuroinflammation-related microstructural changes in RRMS and NMOSD patients.
•We evaluated MS and NMOSD using DTI, FW imaging and NODDI.•RRMS group had significantly higher diffusivity in lesions.•RRMS group had significantly lower intracellular volume fraction in lesions.•TBSS analysis showed increased water content in RRMS group.•These results may reflect microstructural changes in MS and NMOSD.