Accelerometry in Multiple Sclerosis

Multiple sclerosis (MS) is a leading cause of disability affecting young people in the prime of their life (ages 20-50) and negatively impacting their quality of life. Although medications may reduce the risk of relapses for those with relapsing remitting MS (RRMS), there are no treatments to slow disability accrued from the progressive subtypes of MS (prMS). The lack of sensitive outcome measures capable of detecting disease progression is a primary limitation to the development of new therapies for prMS. The current gold standard measure of disability, the Expanded Disability Status Scale (EDSS), is a non-linear, ordinal scale with less than optimal reliability and responsiveness. New biomarkers of disability are desperately needed.

Wearable tri-axial accelerometers are a non-invasive, objective and inexpensive technology that records human movement in a real-world context despite human limitations of mobility and cognition. Accelerometers offer an unprecedented opportunity to capture objective information about disability outside the clinic/lab setting. For these studies, we capitalize upon the strengths of our motion laboratory to quantify walking, which impact physical activity, in collaboration with advanced analyses of accelerometer data developed through a SMART group (Statistical Methods and Applications for Research in Technology) in the Department of Biostatistics. Our group will use advanced analyses to determine details about the quality, quantity, and intensity of physical activity relative to MS disease progression.

We hypothesize that minute-to-minute accelerometry data will be capable of tracking MS disability. As a first start, we will perform a cross sectional study of individuals with MS, and track their physical activity minute-by-minute over 1-7 days. From these data, we will quantify physical activity patterns, activity intensity and circadian patterns, all from a person’s free-living environment. We will then compare these data to age matched healthy controls and the current clinical gold standard of the EDSS and standardized walking tests. We hypothesize that metrics gathered from wearable accelerometers will have the resolution and reproducibility to detect disability earlier in the disease process than the EDSS and other standardized tests, and will distinguish between individuals with RRMS and prMS.

Individuals with prMS represent an underserved population; the studies proposed here provide an objective method to evaluate accelerometry as a viable biomarker that may be sensitive enough to track disability over time and discriminate between MS subtypes. This novel measure of physical activity is captured in a person’s free-living environment allowing us to quantify community activity, thus finally linking quality of life to MS disability. Finally, this information is critical for the timely development of pharmacologic and rehabilitative interventions designed to slow progression or improve function.