TUESDAY, March 10, 2026 (HealthDay News) -- For people with multiple sclerosis (PwMS), within-person reductions in daytime activity patterns precede clinical disability worsening, according to a study published online March 4 in Neurology.
Kathryn C. Fitzgerald, Sc.D., from the Johns Hopkins School of Medicine in Baltimore, and colleagues examined whether accelerometry detects subtle change in disability among PwMS. Data were included for 238 PwMS aged 40 years or older with approximately annual brain magnetic resonance imaging (MRI) who wore GT9X Actigraph accelerometers every three months over three years.
The researchers found that 120 PwMS experienced Expanded Disability Status Scale-plus (EDSS+)-confirmed progression during a mean of 2.9 years. There was an average decline of 43,737 activity counts in total activity (2.0 percent decline per year). A higher risk for EDSS+ was seen in association with within-person decreases in daytime activity (particularly between 8:00 and 14:00). A one-standard deviation decrease in within-person activity from 8:00 to 10:00, 10:00 to 12:00, and 12:00 to 14:00 was associated with a 1.20, 1.24, and 1.23 higher risk for EDSS+-confirmed disability progression, respectively. Within-person declines in morning activity (8:00 to 10:00) were also associated with greater whole-brain, deep gray matter, and thalamic volume loss in MRI models (−0.18, −0.34, and −0.35 percent, respectively). Over time, lower between-person mean moderate-to-vigorous physical activity was associated with lower brain volumes, but no association was seen with EDSS+.
"Timely identification of patients at risk for disease progression is essential to reduce long-term disability," Fitzgerald said in a statement. "Using a relatively inexpensive and accessible device around the wrist may help us identify early changes in the disease."
Several authors disclosed ties to the biopharmaceutical industry.