Quantitative sensory and motor measures detect change over time and correlate with walking speed in individuals with multiple sclerosis

Background: Impairments of sensation, strength, and walking are common in multiple sclerosis (MS). The relationship among these abnormalities and how they change over time remains unclear. Objective: To determine the extent that quantitative lower extremity sensory and motor measures detect abnormalities over time, relate to global disability, and to walking speed in individuals with MS. Methods: This prospective, longitudinal analysis evaluated 136 MS subjects. Measures included measures of leg strength, sensation, the Expanded Disability Status Scale(EDSS) and timed 25-foot walk test (T25FW). Mixed effects regression models were used. Results: Our cohorts mean age is 44.3 +/- 10,8 years (mean +/- SD), EDSS score range 0-7.5, 66% were females, and follow-up time was 2.1 +/- 1.2 years. Strength significantly changed over time; the RRMS group demonstrated the greatest changes in ADF (3.3 lbs/yr) while the PPMS group showed significant HF changes (-2.1 lbs/yr). Walking speed was affected most by HF, especially in the weakest individuals (HF <20 lbs); T25FW increased by 0.20 s for each 1 lb loss (p=0.001). Likewise T25FW changed by 0.19 s for each 1 lb change in ADF <0.01). Conclusion: Quantitative measures detected changes in sensation and strength over time, despite a stable respective functional systems scores of the EDSS. Quantitative measurement tools may improve the sensitivity of disability measures in MS and further investigation of these tools as outcomes in future clinical trials of rehabilitative and neuroreparative interventions is warranted. (C) 2014 Elsevier B.V. All rights reserved.