Disease burden in pediatric MS is tied to physical activity level

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - Lower physical activity was associated with a higher disease burden in children with multiple sclerosis (MS), a new study shows.

In contrast, children with MS who exercised strenuously had lower T2-lesion volumes and lower relapse rates, suggesting that the physical activity may have a protective effect for them, the authors wrote online August 12 in Neurology.

"While we predicted that this relationship would be present, based on our own clinical observations and studies in healthy children that suggested relationships between volumes of specific brain regions and higher fitness, we were surprised that the relationship held with lesion volume and relapse rate," senior author Dr. E. Ann Yeh, of the Hospital for Sick Children in Toronto, Ontario, Canada, told Reuters Health by email.

Dr. Yeh and colleagues examined the association between physical activity and disease activity, depression, and fatigue in 31 children with MS 79 children with monophasic acquired demyelinating syndrome (mono-ADS), with nearly equal numbers of boys and girls in each group.

The children with monophasic illnesses were included to determine differences between patients with relapsing-remitting MS and those without relapsing disease.

All of the children were between the ages of five and 18.

The authors administered the PedsQL Multidimensional Fatigue Scale, Center for Epidemiological Studies Depression Scale, and Godin Leisure-Time Exercise Questionnaire. They performed Quantitative magnetic resonance imaging (MRI) analysis to obtain whole-brain and T2-lesion volume in a subset of 60 participants.

The children with MS were less active than those with mono-ADS, possibly due to disease activity, perceived limitations, or symptoms such as depression or fatigue, the authors wrote.

Specifically, over the course of a week, children with MS reported less strenuous physical activity (median 0.0 vs 27.0 metabolic equivalents, or METs; p=0.0012) and total physical activity (median 40.0 vs 54.0 METs; p=0.0284) than children with mono-ADS.

Patients with MS who took part in greater amounts of moderate physical activity had fewer sleep and rest fatigue symptoms (r=-0.4). Those who reported strenuous physical activity had smaller T2-lesion volumes (r=-0.66) and lower annualized relapse rates (r=-0.66), but the authors found no associations between total brain volume and participation in physical activity.

"Children with MS suffer from relapse rates up to four times the rates of adults with MS. Depression and fatigue are also exceedingly common, with up to 75% of children with MS affected by these disabling problems. Few studies have evaluated lifestyle and other factors that might improve outcomes in these children," Dr. Yeh said.

"This study is only the beginning," Dr. Yeh said. "While our results are preliminary, we hope that they will lead to further investigations examining the potential relationships between these factors and outcomes in pediatric MS and other disorders."

"We need to understand the parts of this puzzle, starting from the most basic questions related to whether brain structure changes in specific areas that have been implicated in physical activity, to whether specific brain functions change with physical activity, and whether specific symptoms are associated with levels of physical activity, exercise, or fitness," she added.

Dr. Yeh said her team is planning longitudinal studies to explore the relationships between physical activity, MS disease activity and symptoms as well as to find practical ways to help children increase their physical activity, such as through health coaching.

Dr. Maria A. Rocca, of the San Raffaele Scientific Institute in Milan, Italy, co-wrote an editorial accompanying the journal article.

"These findings are in line with similar findings in adult patients with MS, stroke, or psychiatric diseases, such as depression," Dr. Rocca told Reuters Health by email. "This study was important because it was performed in pediatric patients. Pediatric patients with MS tend to reach more severe disability younger than do adult patients, with high costs for their families and society. Consequently, identifying the factors that might ultimately influence their disability level might reduce costs and give them a better quality of life."

Dr. Rocca agreed with the authors that longitudinal studies are needed to clarify the relationships between physical activity and disability, relapse rate, and fatigue.

The MS Society of Canada, Canadian MS Scientific Research Foundation, and the SickKids Foundation supported this research. Three study coauthors and the three editorial coauthors reported relevant relationships.

SOURCE: http://bit.ly/1L6zewW

Neurology 2015.

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