Cost of walking, exertional dyspnoea and fatigue in individuals with multiple sclerosis not requiring assistive devices.

Abstract Objective: To assess the cost of walking in individuals with multiple sclerosis and to investigate its relationship with dyspnoea and fatigue. Methods: In 46 individuals with multiple sclerosis and in 36 healthy controls, the cost of walking was measured during the 6-min walk test. Perceived breathlessness after walking was rated on a visual analogue scale and corrected for the distance walked. The subjects’ perceived effect of fatigue was assessed by means of the Modified Fatigue Impact Scale. Results: The cost of walking was significantly higher in individuals with multiple sclerosis than in controls; however, individuals with multiple sclerosis with normal walking speeds had normal costs of walking. The cost of walking was directly related to the degree of disability, but not to breathlessness perception and fatigue. Individuals with an Expanded Disability Status Scale score greater than 2.5 were highly likely to show an increased cost of walking. Breathlessness perception was higher than in controls and was related to fatigue. Conclusion: Individuals with multiple sclerosis, even with mild disability and not requiring any assistive devices, may have an increase in cost of walking. This suggests that an aerobic training programme should be considered in these patients. Energy expenditure when walking is not a determinant of fatigue or exertional dyspnoea in individuals with multiple sclerosis and low levels of disability. Key words: walking; fatigue; disability; multiple sclerosis. J Rehabil Med 2010; 42: 719–723