Neuromyelitis optica spectrum disorder and multiple sclerosis: Differentiation by a multimodal approach

- NMOSD differs from MS by the structural brain changes.
- The brain changes of NMOSD patients were milder than those of MS patients.
- Thalamus is the important region for discrimination NMOSD from MS.

BackgroundNeuromyelitis optica spectrum disorder (NMOSD) differs from multiple sclerosis (MS) by prognosis and approach to treatment, and it is thus important to distinguish NMOSD from MS.ObjectiveWe evaluated the structural brain abnormalities in patients with NMOSD and with relapsing-remitting MS (RRMS) using with MRI.MethodsTwenty-one NMOSD patients with antibodies against aquaporin 4, 32 patients with RRMS, and current age- and sex- matched 39 healthy subjects underwent 3-T MRI. The differences in gray matter volume and fractional anisotropy (FA) value among the three groups were evaluated.ResultsThere were significant global gray matter volume reductions of NMOSD and RRMS groups, compared to the healthy subjects. Significant and diffuse decreases in FA values were observed in both the NMOSD and RRMS patients. Significant gray matter volume and FA value reductions of the RRMS patients in the bilateral thalami and some regions were observed compared to the NMOSD patients.ConclusionLarger brain structural changes were seen in the RRMS group compared to the NMOSD group, and among them, the thalamus was revealed as the important region for the discrimination of these two diseases. MRI analyses of the brain may be helpful in differentiating NMOSD from RRMS patients.