Sustained Attention and Gait Pattern Changes During the 6-Minute Walk Test in Persons with Multiple Sclerosis

Abstract

Background and purpose: It is unknown whether persons with multiple sclerosis (pwMS) can retain sustained attention and gait quality during long-distance walking tests. This study aimed to investigate changes in sustained attention and gait parameters during prolonged walking in pwMS with different levels of disability and healthy controls (HCs) and correlations of these changes with self-reported daily life difficulties. Methods: The 6-Minute Walk Test was performed with an auditory sustained attention task while wearing inertial measurement sensors. Participants were asked to respond verbally as quickly as possible to randomly presented auditory stimuli during 6 minutes of walking. The accuracy of answers, average reaction time, and gait parameters per minute were determined. Results: Thirty pwMS with mild disability (Expanded Disease Status Scale [EDSS] < 4.0), 16 pwMS with moderate-to-severe disability (EDSS 4.0 to 6.5), and 27 age-gender matched HCs were included. A significant group-by-time interaction effect as found for reactions times, which increased in mild and moderate-to-severe disability groups but not in HCs. Gait parameters deteriorated over time in all groups, but no significant group-by-time interaction was found. The decrease in sustained attention was not related to changes in gait or clinical outcomes, while deterioration in gait parameters was associated with perceived walking disability and dual-task difficulties in daily life. Discussion and Conclusions: Sustained attention during walking declined over time in pwMS, but not in HCs. However, gait parameters deteriorated in all groups. Worsening gait during simultaneous cognitive task execution may contribute to walking and dual-task difficulties in pwMS.