Dual-Task Walking in Multiple Sclerosis: Correlates, Moderators, and Consequences

The ability to walk while completing a secondary task, dual-task walking (DTW), poses notable challenges for individuals affected by neurological disorders, such as multiple sclerosis (MS), who experience both cognitive and motor problems secondary to their disease. However, DTW is an everyday activity that has putative importance for optimal function. Although some research in the past decade has begun to examine changes in DTW in MS, there is still limited work to understand the predictors of DTW, the factors that might moderate relationships between baseline cognitive and motor function and DTW ability, and its consequences (e.g., for quality of life [QoL] or fall risk). To contribute to the understanding of these phenomena and their intersections, three secondary data analyses of two relatively large data sets in the area were conducted to address five major aims. The first step was to identify of the most relevant of these inherently involved domains (cognitive [aim 1] and motor [aim 2] abilities). Lasso regression for inference was performed to address this question for both cognitive (South Shore Neurologic Associates, PC data) and motor (University of Kansas Medical Center [KUMC] data) domains. Next, evaluations to explore the moderating role of the psychological impacts that are common in MS (e.g., depression and falls self-efficacy) were undertaken to determine whether the relationships between cognitive and motor function and DTW ability are different for individuals with different levels of these factors using regression with factor scores performed with each data set (aim 3). As a final step, relationships between DTW and distal outcomes like QoL (cross-sectionally using both data sets and factor score regression; aim 4) and falls (cross-sectionally and longitudinally using KUMC data and negative binomial regression; aim 5). These studies contribute to the corpus of knowledge about DTW in MS in needed ways.