Walking while talking—Difficulties incurred during the initial stages of multiple sclerosis disease process☆
Introduction
Multiple sclerosis (MS) is an autoimmune disease of the central nervous system causing progressive disability in young adults. Most MS patients (85%) complain of disturbances in gait [1] and more than 66% do not retain the ability to walk 20 years after diagnosis [2], [3]. Recently, several studies demonstrated gait deficits early in the disease process, even in relapsing remitting (RR) MS patients with minimal, no gait or balance deficits on clinical examination [4], [5], [6].
Walking has traditionally been considered automatic or reflex controlled, requiring minimal attentional resources, though a recent review suggested that walking control could be attentionally demanding [7]. In order to clarify this issue, various investigation models have tested the interaction of cognitive-walking dual tasks in healthy and patient populations. Dual tasking refers to the ability to perform two actions simultaneously. Studies have researched the effects of executing concurrent cognitive tasks while walking in people with different neurological pathologies, such as Alzheimer's [8] and Parkinson's disease [9]. These studies suggested that speed and accuracy of walking is affected by simultaneously performing a cognitive task. As well as having implications for everyday life, where one is frequently required to do two things at once, dual-tasking difficulties may help explain the high risk of falls [8].
To date there appears to be a few possible explanations for the occurrence of a dual-tasking deficit. One is postulated on basic damage to the motor system eventually leading to a higher demand of conscious attention during the performance of several tasks [10]. Another possibility is that in specific neurological pathologies, working memory capacity is reduced due to overload by previously normal loads of motor and cognitive content [11]. One more possibility is that rather than basic working memory capacity being the problem, a deficit in the attention control system exists, allocating attention between concurrent demands [11].
A recently published case–control study investigated walking and attention interaction in MS patients. Compared to healthy controls, MS patients (n = 18, EDSS = 2.7) demonstrated slower velocity and elevated swing time variability in gait performance under cognitive dual task conditions [12].
The question that should be asked is at which stage of the MS disease process do dual task conditions affect gait performance, specifically which gait parameters are affected and to what extent.
The first neurological presentation suggestive of MS is defined as a clinically isolated syndrome (CIS), with 21% of the patients presenting with optic neuritis, 46% with long tract motor symptoms and signs, 10% with a brainstem syndrome and 23% with multifocal abnormalities [13]. Even at this early disease stage, patients may experience mobility deficits [14]. Previous studies have proven that cognitive dysfunction is also prevalent at the early stages of the disease [15], [16]. Recent research on 67 probable MS patients revealed that following completion of a battery of neuropsychological tests, cognitive impairment was detected in 53.7% of the patients. Verbal abilities and attention span were most frequently affected [17].
Raising awareness, among both professionals and early onset MS patients of potential walking while talking difficulties, is important in order to plan treatment protocols, everyday activities and clinical assessments.
The objective of the present study was to evaluate gait in patients with CIS, up to 3 months from onset, and to determine the effect of a cognitive task on spatio-temporal gait parameters.
Section snippets
Patients and subjects
Fifty-two early onset CIS patients (36 women and 16 men), mean age of 35.2 ± 1.3 years (range 20–45), volunteered to participate in the study. All patients were distinguished by having experienced a first well-defined neurological event consistent with demyelination, confirmed by neurological examination and Fazekas’ criteria of brain MRI [18]. A diagnosis of possible MS was based on Poser's criteria (clinically probable MS C2 or clinically probable MS C3) [19] or according to the revised
Results
The CIS patient group had a mean duration of 54.0 ± 6.2 days since onset of symptoms. The EDSS score was 1.7 ± 0.2 representing minimal neurological disability. Other participant related clinical scores are outlined in Table 1.
Table 2 refers to the gait parameters during normal walking, derived from the system's software program. Significant differences between patients and healthy subjects were associated with step time and length, double support time and width of base of support. Although both
Discussion
In the current study, gait parameter impairment in CIS patients were identified. When compared to healthy subjects, patients walked slower, with larger step asymmetry, with a wider base of support and a prolonged double support period. In accordance with our hypotheses, CIS patients significantly changed gait patterns when performing the walking-cognitive dual task compared to the healthy controls. Furthermore, in contrast to the control group, the patient's gait demonstrated a wider and fixed
Conflict of interest
The authors confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.
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2020, Multiple Sclerosis and Related DisordersCitation Excerpt :However, there is no consensus on which tasks combination creates higher interference (Leone et al., 2015; Patel et al., 2014). The effects of DT on walking (e.g., reduction of gait velocity, increase of double support duration) (Kalron et al., 2010; Learmonth et al., 2014; Pau et al., 2018) may depend on the type of the concurrent task in MS: for example, many cognitive tasks require a verbal response modality (talking, counting), adding the potential interference of speech articulation on walking. At the same time, different walking and balance requirements under DT condition may produce specific detrimental effects on cognitive performance (Hamilton et al., 2009) or alter the attention allocated to the concomitant tasks (i.e., altered prioritization strategy) in PwMS, depending on the perceived difficulty of the tasks (Allali et al., 2014).
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2020, Contemporary Clinical TrialsCitation Excerpt :During the dual-task condition, we will use the Modified Word List Generation (WLG) task as the dual-task. This is a previously validated task that tests phonemic verbal fluency and has been found to elicit dual-task interference in MS. [17,39,40] Using standardized procedures, the WLG task will be carried out in the sitting position as a single-task and during walking as a dual-task to determine dual-task costs both with respect to gait and the cognitive task. Dual-task costs will be determined as: [100*(single-task value – dual-task value)/single-task value] both for gait speed and the WLG.
Spinal cord involvement in multiple sclerosis and neuromyelitis optica spectrum disorders
2019, The Lancet Neurology
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This work was performed in partial fulfillment of the requirements for a Ph.D. degree of Alon Kalron, Sackler Faculty of Medicine, Tel Aviv University, Israel.