Gait abnormalities in minimally disabled people with Multiple Sclerosis: A 3D-motion analysis study

Background: People with Relapsing-Remitting Multiple Sclerosis (pwRR-MS), may be affected by subclinical gait impairment. The Expanded Disability Status Scale, the most used scale to assess MS related disability, may be insensitive to subclinical gait disability. Minor gait abnormalities may be detected by three Dimensional-Gait Analysis (3D-GA). Objectives: To investigate gait pattern in minimally disabled pwRR-MS by 3D-GA during walking (single task, SinT), and cognitive dual tasks (CogDT) and to evaluate correlations between altered gait parameters, cognitive scores, lesion load (LL) and brain atrophy measures. Methods: Twenty-two pwRR-MS and twenty-one healthy controls (HCs), underwent neuropsychological (NP) evaluation, and brain MRI to assess brain volumes and lesion load (only in pwRR-MS) and 3D-GA. Results: Both pwRR-MS and HCs were considered cognitively preserved (CP). During SinT pwRR-MS, compared to HCs, showed an impairment of velocity (increase of cycle time), stability (increase of stance time, swing time and coefficients of variability (CV) of swing time) and kinematic (increase of ankle dorsiflexion) parameters. During CogDT, the changes of velocity and stability parameters observed in SinT were confirmed. Moreover, a statistically significant increase of the double limb support was observed. Regarding the kinematic parameters, during CogDT, an increase of ankle dorsiflexion during mid and terminal stance phases of gait cycle was observed. No significant correlations were found between gait abnormalities and cognitive status or MRI structural damage in both groups. Conclusions: The subclinical abnormal gait in asymptomatic and CP pwRR-MS, may be detected by 3D-GA.