Remote Monitoring of Daily Step Counts Could Help Clinicians Track Changes in Disability in Patients with MS

Researchers used a Fitbit Flex2 to examine the correlation between step counts and changes in the brain and spinal cord associated with multiple sclerosis.

Measuring spinal cord atrophy in individuals with multiple sclerosis (MS) can be helpful in predicting time to disease relapse and progression of disability. Recent advances in imaging, specifically the use of phase-sensitive inversion recovery (PSIR) imaging, allow for the measurement of total cord areas (TCA), gray matter areas, and white matter areas in patients with MS.

Gray matter atrophy in the cervical and thoracic spinal cord areas has been linked to increased disability in the upper and lower limbs of patients with MS. In a recent study sponsored by the National MS Society, Valery J. Block, D.P.T.Sc., and colleagues from the University of California, San Francisco used PSIR imaging to evaluate the association between spinal cord atrophy and physical disability in patients with MS.

The study included 50 adults with a clinical diagnosis of either relapsing or progressive MS who could walk for at least two minutes. Each participant was given a Fitbit Flex2 device and asked to wear it as much as possible for 30 days. Daily step counts were monitored remotely and used to assess daily physical activity. Brain and spinal cord atrophy were assessed via MRI scans.

Results from the study were published in the Multiple Sclerosis Journal in December 2022. Data showed that participants with lower average daily step counts) had greater spinal cord atrophy, as evidenced by decreased total cord area, gray matter and white matter areas in the cervical and thoracic spinal regions, compared with people with higher step counts. Lower step counts also correlated with higher levels of disability, measured by walking speed, endurance, mobility and bladder and bowel function.

Based on the results from this study, Block and colleagues propose that remote monitoring of daily step counts could be used as an indirect and noninvasive way for clinicians to track changes in physical function or disability in patients with MS.

“These data are encouraging when considering opportunities for future interventions to improve symptoms and quality of life in people with MS — interventions that improve STEPS (average daily step counts) might also favorably impact historically difficult-to-treat symptoms such as fatigue and pain, or vice versa,” they wrote

Limitations of this study include the small sample size and its cross-sectional design. The authors recommend larger longitudinal studies to gain more insight into the direction of the correlation between physical function and disability changes.