Background: Multiple Sclerosis (MS) is a disease characterized by ambulation deficits, fear of falling and subjective fatigue. Altered ambulation and fear of falling have been correlated with spatiotemporal gait parameters, however evidence for the correlation between subjective fatigue and gait parameters in people with multiple sclerosis (PwMS) is unclear. In previous studies, a reduction in walking speed correlated with higher scores on the MSWS-12, as well with a higher disability score of the EDSS.
Objectives: The purpose of this study was to examine the relationship between patient reported outcomes (PROs) and gait parameters in different disability levels of PwMS.
Methods: A convenience sample of 47 PwMS (53.8 ±11.2 yrs, 14M) were recruited from an outpatient neurology clinic. Inclusion criteria: no MS exacerbation within 3 months and independent ambulator x 25 ft. The Patient Determined Disease Steps (PDDS) was used to categorize the subjects into 3 disability groups: low (PDDS:0-2; n=16 ) medium (PDDS: 3-4; n=19 ) and high (PDDS: 5-6; n= 12). Subjects completed the following PROs: Modified Fatigue Impact Scale (MFIS), with subsets of physical, cognitive and psychosocial; Modified Falls Efficacy Scale (MFES); and the 12-item MS Walking Scale (Amb-12). Gait analysis was collected using the ProtoKinetics ZenoTM System. Subjects ambulated at their self selected gait speed for one pass (20 ft).
When comparing the low to medium disability group and the low to high disability group, differences were noted in all gait parameters (velocity, stride length and double support time) and all PROs, except MFIS-cognitive (p<0.05). When comparing the medium to high disability group, differences were only seen in the Amb-12 and gait velocity (p<0.05). Cognitive fatigue showed no significance between groups. Results of the total cohort showed correlations (p<0.05) between the Amb-12 and the above gait parameters. The MFES correlated with stride length and velocity but not double support. Of the MFIS categories, only the physical subset had a correlation with velocity (p<0.05). Conclusions: This study has shown that Amb-12 and MFES but not MFIS, possess a significant correlation with gait parameters when evaluating the total cohort. When analyzing the different disability groups, the aforementioned PROs are greater predictors of gait performance versus patient perceived fatigue (MFIS). Reports of fatigue do not seem to correlate with different disability levels in PwMS.