Wearable sensors find sluggishness that may signal MS worsening
Subtle drops in morning activity may be early progression signs
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A woman eats a light breakfast while preparing to exercise.
- Wearable sensors detect subtle morning activity drops in MS patients.
- These changes predict worsening disability and brain tissue loss.
- These devices could enable earlier detection of MS progression.
Subtle drops in activity levels detected by wrist-worn sensors — especially in the morning — may predict worsening disability and brain tissue loss in people with multiple sclerosis (MS), according to a study.
The data suggest that continuous monitoring with these devices could reveal early signs of disease progression before worsening can be detected with standard clinical measures.
The study, “Association of Changes in Activity Patterns With Brain Atrophy and Disability Progression in People With Multiple Sclerosis,” was published in Neurology, the medical journal of the American Academy of Neurology (AAN).
“More research is needed to confirm these findings, but it’s exciting to think that using easily accessible devices could help us predict who is at risk of worsening disease and potentially prevent those changes,” Ellen Mowry, MD, study lead author and a neurologist at Johns Hopkins School of Medicine in Baltimore, said in an academy press release. “Detecting small changes could also help us speed up research on new treatments.”
MS is a chronic neurological disease in which the immune system mistakenly damages nerve fibers in the brain and spinal cord. This damage interferes with communication between the brain and the rest of the body and can lead to gradually worsening problems with movement, balance, and other functions. However, current measures of disease progression often cannot detect subtle MS symptom changes, which may delay adjustments in care and require long clinical trials to detect a measurable effect from new drugs.
Small changes may be important
Mowry’s team tested whether wearable sensors could detect small changes in daily activity that may signal worsening symptoms.
The wrist-worn sensors measured different aspects of daily behavior. They recorded light, moderate, and vigorous physical activity, as well as sedentary time, or periods spent sitting or inactive. They also tracked circadian rhythms, the body’s internal 24-hour cycle that regulates sleep and wake patterns.
“Timely identification of patients at risk for disease progression is essential to reduce long-term disability, but the current tests for measuring MS disability are not designed to detect small changes,” said Kathryn C. Fitzgerald, an assistant professor at Johns Hopkins and the study’s first author. “Using a relatively inexpensive and accessible device around the wrist may help us identify early changes in the disease.”
The study involved 238 MS adults with an average age of 54.8. They had lived with the disease for an average of 13.2 years. At the beginning of the study, patients had an average Expanded Disability Status Scale (EDSS) score of 3, indicating mild to moderate disability but retaining the ability to walk.
Patients were asked to wear a wrist sensor continuously for two weeks at a time, every three months for about three years. Every six months, patients completed tests to measure disability. They had MRI scans at the start of the study and again after two years.
During the study, 120 patients experienced confirmed worsening of disability, defined as a sustained increase in EDSS scores lasting at least six months.
Patients who were less active during the day, especially in the morning, were more likely to see their disease progress. A decrease in activity between 8 a.m. and 10 a.m. was linked to a 20% higher risk of confirmed worsening of disability.
Reductions in activity levels during the same period were also associated with greater loss of brain volume. Certain regions of the brain involved in physical and cognitive declines in MS were particularly affected.
The findings suggest that declines in daytime movement may precede clear, clinical signs of worsening MS. Because wearable sensors are simple and noninvasive, they may eventually become useful tools for monitoring disease and detecting subtle changes earlier than traditional clinical tests.
“We identified within-person changes in real-world physical activity and circadian rhythm patterns that preceded disability progression and brain atrophy [loss of brain tissue],” the researchers wrote.
However, the study had limitations. It did not include a comparison group of people without MS, which would help determine how much of the change in activity is due to normal aging. In addition, the patients were older and had mild to moderate disability, so the findings may not apply to younger patients or those with milder disease.
