Comparing Three Dual-Task Methods and the Relationship to Physical and Cognitive Impairment in People with Multiple Sclerosis and Controls

Abstract

Dual-tasking (DT) is a measure to detect impairments in people with multiple sclerosis (MS). We compared three DT methods to determine whether cognitive (Montreal Cognitive Assessment (MoCA)) or physical disability (Expanded Disease Severity Scale; EDSS) was related to DT performance. We recruited MS participants with low disability (<3 EDSS, n = 13) and high disability (≥3 EDSS, n = 9) and matched controls (n = 13). Participants walked at self-selected (SS) speed on an instrumented walkway (Protokinetics, Havertown, USA), followed by DT walks in randomized order: DT ABC (reciting every second letter of the alphabet), DT 7 (serially subtracting 7's from 100), and DT 3 (counting upwards, leaving out multiples and numbers that include 3). DT 7 resulted in the most consistent changes in performance. Both MS and control groups reduced velocity and cadence and shortened step length during DT with no significant differences between groups. Control subjects widened stride width by about 1 cm while MS subjects (collapsed as one group) did not. MS subjects with higher disability significantly increased percentage time in double support during DT compared to SS (F = 12.95, p < 0.001). The change in DS was related to cognitive and not physical disability (r = 0.54, p < 0.05).

Effect of a Combined Program of Strength and Dual Cognitive-Motor Tasks in Multiple Sclerosis Subjects

“…The DTC for each group and variable was calculated from the percentage of variance between normal gait values (NG) and dual-task gait (DTG) [ 14 ]. …”

“…Although the effectiveness of rehabilitation and pharmacological interventions for MS has improved substantially in the recent decades, these interventions are only aimed at delaying the progress of the disease [ 4 ]. Physical exercise has been consistently demonstrated to have therapeutic effects in MS subjects, as it improves MS-associated motor and cognitive symptoms, including muscle weakness [ 5 , 6 ], balance and coordination [ 7 , 8 ], muscle fatigue [ 9 , 10 ], vascular and metabolic comorbidities [ 11 , 12 ], cognitive/motor dysfunction [ 13 , 14 ], and more recently the pathophysiology of the disease [ 15 , 16 ].…”

“…DT helps assess changes in motor activity patterns while a cognitive task is performed concurrently. Simultaneous activities compete for resources, which is defined as “dual-task cost” (DTC) [ 14 , 21 ].…”

Vigorous cool room treadmill training to improve walking ability in people with multiple sclerosis who use ambulatory assistive devices: a feasibility study

“…If the participants required additional assistance while walking, they were assisted using a gait belt by a member of the research team, who was a physiotherapist. Gait parameters (stance phase (%), swing phase (%), double support phase (%), and walking speed (cm/s)) were extracted from the walkway as previously described [38].…”

Bipedal hopping timed to a metronome to detect impairments in anticipatory motor control in people with mild multiple sclerosis

“…Many PwMS perform in the normal range (a floor effect) and changes up to 20% on this measure are needed to be considered clinically significant (Hobart, Blight, Goodman, Lynn, & Putzki, 2013). Several groups are developing more complex motor tasks in order to detect subtle deficits, such as dual-tasking Kirkland, Wallack, Rancourt, & Ploughman, 2015) and standing balance (Spain et al, 2012). Kirkland et al (2016) demonstrated that a bipedal hopping task can reveal motor deficits in a measurable way, even in participants who do not surpass the six-second clinical cut-off of the T25FWT (Kirkland et al, 2016).…”