Validation of the Korean Version of the 12-Item Multiple Sclerosis Walking Scale and Application to Neuromyelitis Optica Spectrum Disorder

Background and Purpose Gait problems are a primary complaint in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). The 12-item Multiple Sclerosis Walking Scale (MSWS-12) is a patient-reported measure assessing the impact of MS on the walking ability. We aimed to adapt and validate the Korean version of the MSWS-12 for the Korean population with MS and NMOSD. Methods Thirty-four MS and 35 NMOSD patients were recruited. The MSWS-12 questionnaire was translated into the Korean language and evaluated for its validity and reliability in these patients. Results The MS and NMOSD patients had mean ages of 35.9 and 42.1 years, respectively, median disease durations of 5.6 and 7.2 years, median Expanded Disability Status Scale (EDSS) scores of 2.75 (range, 0-6.5) and 3.5 (range, 0-7.5), and median baseline MSWS-12 total scores of 25 [interquartile range (IQR), 2.60-53.65] and 25 (IQR, 7.29-50.00). The baseline MSWS-12 total score in the patients with MS showed strong correlations with scores for the EDSS, timed 25-foot walk (T25FW), Multiple Sclerosis Impact Scale-29 (MSIS-29) physical dimension, and 36-item Short-Form Health Survey (SF-36) physical component summary (PCS), with Spearman's correlation coefficients (rho) of 0.922, 0.756, 0.933, and -0.874, respectively. In patients with NMOSD, the baseline MSWS-12 total score showed strong correlations with scores for the EDSS, MSIS-29 physical dimension, and SF-36 PCS (rho=0.769, 0.910, and -0.852, respectively), and moderate correlations with scores for the T25FW and Fatigue Severity Scale-9 (rho=0.597 and 0.630, respectively). Conclusions The Korean version of the MSWS-12 appears to be a valid and reliable scale that can be used for Korean patients with MS. The MSWS-12 can also be applied to patients with NMOSD.