Attending to the task: Interference effects of functional tasks on walking in Parkinson’s disease and the roles of cognition, depression, fatigue, and balance11No party having a direct interest in the results of the research supporting this article has or will confer a benefit on the author(s) or on any organization with which the author(s) is/are associated.

Abstract

Objective To evaluate the interference effects on walking of functional activities in the home in people with Parkinson's disease (PD) and the contribution of clinical symptoms to disturbance of gait. Design A repeated-measures trial, using a dual-task paradigm to evaluate the attentional demands of functional activities. Setting Participants' homes and a clinic. Participants Twenty subjects with idiopathic PD and 10 age-, sex-, and education-matched controls. Interventions Subjects performed a simple walking task, a dual-motor task, a dual-cognitive task, and a multiple task, all of which were real-world activities. Main outcome measures Walking speed, mean step length, and step frequency were compared across different tasks for each subject. A battery of clinical outcome measures hypothesized to compete for attention were also conducted: cognition (Hayling and Brixton tests), anxiety and depression (Hospital Anxiety and Depression test), fatigue (Multidimensional Fatigue Inventory), balance (Berg Balance Scale), and disease severity (Hoehn and Yahr score). Results PD subjects walked at a significantly slower speed (26.5%, P Conclusions Competition for attention through additional activities, decreased executive function, depression, fatigue, and impaired balance will increase difficulty in walking for PD subjects. Evaluation of performance during complex functional activities in an appropriate environment should be a focus of therapeutic assessment. Furthermore, functional…