A comparison between subjective and objective measurements of spasticity in neuromyelitis optica spectrum disorder patients.

BACKGROUND: Spasticity is a common and disabling problem in multiple sclerosis (MS), but its effect in other CNS inflammatory demyelinating diseases (CNSIDDs), such as neuromyelitis optica spectrum disorder (NMOSD) is not widely studied. This study aims to compare subjective and objective measurements of spasticity in NMOSD patients and determine associated factors. METHODS: A prospective cross-sectional study was performed on CNSIDD patients attending the Multiple Sclerosis and Related Disorders Clinic at Siriraj Hospital, a tertiary hospital in Thailand, from June to November 2020 was performed. MS, NMOSD, and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) patients were included. Patients' self-rated Numeric Rating Scale (NRS) for spasticity and clinician-evaluated Modified Ashworth Scale (MAS) scores on the same visit were compared and assessed for correlations. Data on characteristics of patients including demographics, number of transverse myelitis (TM) attacks, disease duration, and Expanded Disability Status Scale (EDSS) score were collected. RESULTS: Seventy-nine CNSIDD patients were included with 25 MS, 53 NMOSD, and 1 MOGAD. There was a statistically significant correlation between NRS and MAS scores (r = 0.934, p < 0.001). Spasticity was more commonly observed in NMOSD patients compared to MS (34% vs 8%, p = 0.016). Clinical characteristics strongly associated with spasticity were higher number of TM attacks (p < 0.001), severe TM attacks (p < 0.001), longitudinally extensive transverse myelitis attacks (p < 0.001), longer disease duration (p = 0.025), higher EDSS (p < 0.001), and pyramidal Functional System Scale scores (p = 0.001). CONCLUSIONS: Patients' self-reported NRS score had a good correlation with clinician-evaluated MAS score for spasticity assessment in NMOSD and CNSIDD patients overall. Number and severity of TM attacks were associated with spasticity. Spastic patients had more disability measured by EDSS.