Assessment of Multiple Sclerosis Disability Progression Using a Wearable Biosensor: A Pilot Study

Background: The evaluation of walking activity of people with multiple sclerosis (pwMS) is desirable. We evaluate the power of the correlation of motor parameters detected by the accelerometer in the Samsung Gear S2 smartwatch with multiple sclerosis (MS) disability measures and patient reported outcomes (PROs). Methods: We enrolled 25 relapsing remitting MS patients. We assessed disability with the expanded disability status scale, two-minute walking test (2MWT), timed 25-foot walk test (T25FWT), and nine-hole peg test. We collected PROs measuring fatigue, ambulatory ability, depression, quality of life, and bladder/bowel function. Participants were asked to wear the accelerometer for a period of 30 days. Results: The Spearman's rank correlation coefficient showed a moderate negative correlation between the patient-determined disease steps (PDDS) score with the mean steps/day, a strong negative correlation between the PDDS score with the maximum number of daily steps (MNDS) and a moderate negative correlation between the fatigue severity scale score and MNDS. A moderate negative correlation between MNDS and the 2MWT and a moderate negative correlation between MNDS and the T25FW was found. Conclusion: Our results suggest that motor parameters derived from the accelerometer could be a reliable measure of motor disability in pwMS.