A-03 The Brain–Body Connection in Aging Neurological Populations: Examining the Impact of Exercise and Sedentary Behavior on Brain Structure and Cognitive Functioning in Older Adults with Multiple Sclerosis

Abstract

Abstract Objective Advancements in treatments for multiple sclerosis (MS) have led to an increase in the number of older adults living with the disease. Exercise has been shown to be remarkably beneficial for “healthy aging,” while sedentary behavior has proved to have more deleterious effects. Despite evidence for the impact of these factors, their influence on older adults with MS is largely unknown. The current study utilizes volumetric measures and graph theory to investigate the relationship between physical activity/sedentary behavior, structural brain indices, and cognition in older adults with MS. Method Twenty-seven older adults (55+) with MS were scanned during a structural MRI protocol and cognitively evaluated using the Multiple Sclerosis Functional Composite and Symbol Digit Modalities Test. Graph theory metrics were calculated to examine white matter network properties. FreeSurfer was used to calculate volumes for subcortical structures. Exercise was quantified as the ‘days per week engaged in moderate activity,’ while sedentary behavior was measured as ‘hours per day sitting.’ Results Multiple regression interaction analyses were conducted. Results showed an exercise by age interaction, such that exercise protected against the negative effects of age on thalamic volume and assortivity. Hours sitting per day was shown to add to the negative effects of aging on structural networks even after controlling for exercise. Lastly, exercise was observed to be protective against age-related cognitive decline in this sample. Conclusions This is one of the first studies to examine exercise/sedentariness and brain indices in older adults with MS, pointing to possible brain altering and protective interventions for this group.