We investigated free water eliminated kurtosis-based white matter tract integrity to distinguish microstructural changes in the spinal cords of patients with MS and Neuromyelitis Optica. FA was significant higher in spinal cord white matter in MS (P=0.0025). There was no significant difference in other diffusion model-based metrics. The values of FA seem to be non-specific but robust. Therefore, clinical feasible and more optimized diffusion microstructural models and data acquisitions for spinal cord may be needed to provide an additional information and to be biomarker in patients with MS and NMOSD in vivo.