Motor Cognitive Dual-Task Testing to Predict Future Falls in Multiple Sclerosis: A Systematic Review

Cognitive-Motor Coupling in Multiple Sclerosis: Do Chronological Age and Physical Activity Matter?

Background: People with multiple sclerosis (MS) often demonstrate both cognitive and physical dysfunctions, particularly with greater age and lower physical activity levels, and there is evidence of a relationship between these outcomes (i.e., cognitive-motor coupling) in MS. To date, little is known about cognitive-motor coupling when controlling for chronological age and levels of physical activity. Objectives: We examined cognitive-motor coupling in people with MS while accounting for chronological age and physical activity. Methods: The sample included 290 people with MS between the ages of 22 and 77 years. Participants underwent the Symbol Digit Modalities Test (SDMT) for cognitive processing speed and the California Verbal Learning and Memory Test-Second Edition (CVLT-II) for verbal learning and memory. Participants completed the 6-Minute Walk and the Timed 25-Foot Walk tests for walking endurance and speed, respectively. Participants wore an accelerometer for a 7-day period to measure moderate-to-vigorous physical activity (MVPA). Results: The bivariate correlation analyses indicated that cognitive function had moderate-to-strong associations with motor function (range of rs between 0.433 and 0.459). The linear regression analyses indicated cognitive-motor coupling between SDMT and motor function (with a range of β between 0.139 and 0.145) when controlling for demographic and clinical characteristics. The regression analyses further indicated that the CVLT-II was associated with motor function (with a range of β between 0.125 and 0.135) when controlling for demographic and clinical characteristics. When age and MVPA were entered into the regression analyses, SDMT was still associated with the motor function of individuals (β = 0.119), and CVLT-II was still associated with the motor function of individuals (with a range of β between 0.115 and 0.124). Conclusions: Cognitive-motor coupling is present in people with MS independent of chronological age and levels of physical activity. This warrants further investigation of the underlying mechanism and potential approaches for the management of co-occurring MS-related dysfunction.

Curcumin ameliorates astrocyte inflammation through AXL in cuprizone-induced mice

Curcumin has gained global attention owning to its anti-inflammatory, antioxidant, anticancer, and antimicrobial activities. Curcumin has recently been shown to have well-documented effects on neuroinflammation in multiple sclerosis (MS). Astrocytes, the most widely distributed glial cells in the brain, have a significant influence on the regulation of neuroinflammation in MS. However, it is unknown how curcumin exerts neuroprotective effects in astrocytes. To elucidate the mechanism underlying the effects of curcumin on astrocytes, we explored the effect of curcumin on cuprizone (CPZ)-induced mice in vivo and on primary astrocytes in vitro. In this study, we observed that curcumin significantly ameliorated myelin loss and reduced astrocyte activation in the corpus callosum (CC) region in mice induced with CPZ, and in primary astrocytes stimulated with lipopolysaccharide (LPS). Meanwhile, our research indicated that curcumin may exert neuroprotective effects in CPZ-induced mice by downregulating astrocyte-mediated inflammation by AXL. This study provides new insights into possible targeted therapies for MS.

Hemodynamics of the Frontopolar and Dorsolateral Pre-Frontal Cortex in People with Multiple Sclerosis During Walking, Cognitive Subtraction, and Cognitive-Motor Dual-Task

INTRODUCTION

Higher cortical activity has been observed in people with multiple sclerosis (pwMS) during walking and dual-tasking. However, further studies in overground walking and considering pre-frontal cortex (PFC) sub-areas are necessary.

OBJECTIVES

To investigate PFC activity during a cognitive-motor dual-task (DT) and its single component tasks, in combination with behavioral outcomes in pwMS.

METHODS

Fifteen pwMS (EDSS 3.5 [2-5.5], 42 ± 11 years) and 16 healthy controls (HC, 45.2 ± 13.2 years) performed 3 conditions: single motor-walking (SWT), single cognitive - subtracting sevens (SCT), and a DT. Meters walked and the number of correct answers were obtained from which, respectively, the motor (mDTC) and cognitive (cDTC) DT costs were calculated. A functional Near-Infrared Spectroscopy covering the frontopolar and dorsolateral PFC (DLPFC) areas was used to concentration of relative oxyhemoglobin (ΔHbO2) and deoxyhemoglobin (ΔHHb) in the PFC. A repeated 2-way ANOVA (group × conditions) was used to compare ΔHbO2/ΔHHb and behavioral outcomes.

RESULTS

PwMS walked shorter distances (P < .002) and answered fewer correct numbers (P < .03) than HC in all conditions, while cDTC and mDTC were similar between groups. PwMS presented higher ΔHbO2 in the frontopolar area than HC in the SWT (P < .001). HC increased ΔHbO2 in frontopolar during the SCT (P < .029) and DT (P < .037) compared with the SWT.

CONCLUSION

Higher frontopolar activity in pwMS compared to HC in the SWT suggests reduced gait automaticity. Furthermore, it seems that only HC increased neural activity in the frontopolar in the SCT and DT, which might suggest a limit of cognitive resources to respond to DT in pwMS.

Can Timed Up and Go Test discriminate the risk of falling in patients with Multiple Sclerosis with low to moderate impairment?

PURPOSE

The aim of the study was to discriminate the risk of falling in patients with Multiple Sclerosis with low to moderate impairment who do not use walking aid using the Timed Up and Go (TUG) Test.

METHODS

This study was planned as a prospective descriptive study with 204 patients. Falls were recorded in three-month prospective diaries, and the balance was evaluated using the TUG Test.

RESULTS

By using three-month prospective diaries, the mean age of 109 faller patients and 95 non-faller patients was 35.87 ± 8.35 and 35.35 ± 9.39 years, respectively. The faller group's mean TUG Test score was 9.46 ± 4.14, whereas the non-faller group's was 7.74 ± 2.02 s. The TUG Test has an area under the receiver operating characteristic curve value of 0.666 in discriminating fallers from non-fallers (0.592-0.740, %95 Cl). To identify fallers, the TUG Test score of ≥7.85 s has a sensitivity of 0.65 and a specificity of 0.65.

CONCLUSION

As a result of the present study, the TUG Test was found to have moderate sensitivity and specificity in predicting the risk of falling. It is not a sufficient stand-alone measure for fall risk prediction, so it is recommended that this test be included as part of a comprehensive falls screening programme.

Effect of task difficulty on dual-task cost during dual-task walking in people with multiple sclerosis

BACKGROUND

Cognitive-motor dual-task walking results a decrease in walking performance of patients with multiple sclerosis (PwMS) and it is known as dual-task cost (DTC). However, there is a lack of evidence about the effects of dual-tasks with hierarchical difficulty on DTC in PwMS.

RESEARCH QUESTION

This study aimed to investigate the effect of task difficulty on DTC during cognitive-motor dual-task walking in people with multiple sclerosis (PwMS).

METHODS

32 PwMS and 32 healthy controls were included. The 6-meter walking test (6-Meter WT) with comfortable speed was used as single-task walking condition. For dual-task conditions, walking tasks and cognitive tasks at two difficulty levels (simple and difficult) were combined and DTC for four cognitive-motor dual-task walking conditions as simple motor-simple cognitive (SM-SC), simple motor-difficult cognitive (SM-DC), difficult motor-simple cognitive (DM-SC) and difficult motor-difficult cognitive (DM-DC) were calculated. The 6-Meter WT was used also for simple dual-task walking task. The 6-Meter WT was applied by walking in a narrow base condition for creating a difficult dual-task walking task. For cognitive task difficulty, participants were asked to count backwards by 3 as simple cognitive task and by 7 as difficult cognitive task.

RESULTS

DTC was higher in PwMS than control subjects. DTC in all conditions were different (SM-SC

CONCLUSION

The results suggest that task difficulty affects the magnitude of DTC during cognitive-motor dual-task walking in PwMS. Moreover, difficult walking tasks combined with simple cognitive tasks result greater DCT on walking than simple walking tasks combined with difficult cognitive tasks.

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Key Words

• Dual-task
• Motor-cognitive tasks
• Multiple sclerosis
• Task difficulty
• Walking

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MESH Headings

• Humans
• Male
• Female
• Multiple Sclerosis/physiopathology
• Walking/physiology
• Adult
• Middle Aged
• Cognition/physiology
• Psychomotor Performance/physiology
• Task Performance and Analysis
• Case-Control Studies

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Affiliation(s)

Çağrı Gülşen Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation, Eskişehir Osmangazi University, Eskişehir, Turkey.
Fatih Söke Gulhane Faculty of Physiotherapy and Rehabilitation, University of Health Sciences, Ankara, Turkey
Fatma Aydin Diskapi Yildirim Beyazit Teaching and Research Hospital, Department of Neurology, University of Health Sciences, Ankara, Turkey
Elvan Özcan Gülşen Yunus Emre Vocational School, Department of Health Care Services, Program in Geriatric Care, Anadolu University, Eskişehir, Turkey
Öznur Yilmaz Faculty of Physical Therapy and Rehabilitation, Hacettepe University, Ankara, Turkey
Bilge Koçer Diskapi Yildirim Beyazit Teaching and Research Hospital, Department of Neurology, University of Health Sciences, Ankara, Turkey
Etem Çürük Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation, Korkut Ata University, Osmaniye, Turkey
Şeref Demirkaya Gulhane Faculty of Medicine, Department of Neurology, University of Health Sciences, Ankara, Turkey
Canan Yücesan Faculty of Medicine, Department of Neurology, Ankara University, Ankara, Turkey

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Discriminative ability of the original and short form of the Activities-specific Balance Confidence scale and its individual items for falls in people with multiple sclerosis

BACKGROUND

Balance confidence is an essential component of fall risk assessment in persons with multiple sclerosis (pwMS).

AIMS

The aims of this cross-sectional study were to 1) investigate the ability of the 16-item Activities-specific Balance Confidence scale (ABC-16), 6-item Activities-specific Balance Confidence scale (ABC-6), and each item of the ABC-16 for distinguishing fallers and 2) determine cutoff scores for these scales to discriminate fallers and non-fallers in pwMS.

METHODS

One hundred and fifty-six participants [fallers/non-fallers: 60 (38.5%)/96 (61.5%), median EDSS: 1.5] were enrolled. Balance confidence was assessed using the ABC-16 and ABC-6. The self-reported number of falls in the past three months was recorded. Descriptive assessments, including walking, balance, and cognition were performed. Logistic regression and receiver operating characteristic analyses were conducted to estimate the sensitivities and specificities of the ABC-16 and ABC-6.

RESULTS

Both the ABC-16 (AUC: 0.85) and ABC-6 (AUC: 0.84) had the discriminative ability for falls. Each item of the ABC-16 scale was a significantly related to falls [odds ratio (OR) range: 1.38 to 1.89]. Items 8 and 10 had the highest odds ratio (OR: 1.85; 95%CI: 1.47-2.33, OR: 1.89; 95%CI: 1.49-2.40; respectively). We found cutoff scores of ≤ 70 of 100 (sensitivity: 71.67, specificity: 86.46) and ≤ 65/100 (sensitivity: 76.67, specificity: 79.17) in discrimination between fallers and non-fallers for the ABC-16 and ABC-6, respectively.

CONCLUSION

Both original and short forms of the ABC scale are an efficient tool for discriminating fallers and non-fallers in pwMS. Although all items are related to falls, outdoor walking activities have the strongest associations with falls than other items.

Dual-Task Assessments for Predicting Future Falls in Neurologic Conditions: A Systematic Review

ABSTRACT

This review investigated the ability of dual-task tests to predict falls in people with neurological disorders. Databases were searched to identify prospective cohort studies that analyzed dual-task testing and falls in people with neurological disorders. Reviewers screened studies for eligibility and extracted key information like participant characteristics, intervention details, outcome measures, and significant outcomes. Reviewers assessed methodological quality of eligible studies using the Standard Quality Assessment Criteria. Eighteen studies of strong methodological qualified with 1750 participants were included in the review. Dual-task performances were predictive of future falls in people with Huntington's disease, spinal cord injury, and moderate cognitive impairment, although only one independent study was included for each disability type. In people with stroke, 37% of eligible studies showed dual-task assessments to be predictive of future falls. No dual-task tests predicted prospective falling in people with Alzheimer's or Parkinson's disease. Complex dual tasks seemed to be more predictive of fall risk than simpler dual tasks. Results suggest that disability type, severity of disability, and task complexity play a role in the predictive ability of dual-task assessments and future falling in neurological disorders. Future studies may benefit from using this review to guide the design of effective dual-task assessments and fall interventions.

Brain control of dual-task walking can be improved in aging and neurological disease

The peak prevalence of multiple sclerosis has shifted into older age groups, but co-occurring and possibly synergistic motoric and cognitive declines in this patient population are poorly understood. Dual-task-walking performance, subserved by the prefrontal cortex, and compromised in multiple sclerosis and aging, predicts health outcomes. Whether acute practice can improve dual-task walking performance and prefrontal cortex hemodynamic response efficiency in multiple sclerosis has not been reported. To address this gap in the literature, the current study examined task- and practice-related effects on dual-task-walking and associated brain activation in older adults with multiple sclerosis and controls. Multiple sclerosis (n = 94, mean age = 64.76 ± 4.19 years) and control (n = 104, mean age = 68.18 ± 7.01 years) participants were tested under three experimental conditions (dual-task-walk, single-task-walk, and single-task-alpha) administered over three repeated counterbalanced trials. Functional near-infrared-spectroscopy was used to evaluate task- and practice-related changes in prefrontal cortex oxygenated hemoglobin. Gait and cognitive performances declined, and prefrontal cortex oxygenated hemoglobin was higher in dual compared to both single task conditions in both groups. Gait and cognitive performances improved over trials in both groups. There were greater declines over trials in oxygenated hemoglobin in dual-task-walk compared to single-task-walk in both groups. Among controls, but not multiple sclerosis participants, declines over trials in oxygenated hemoglobin were greater in dual-task-walk compared to single-task-alpha. Dual-task walking and associated prefrontal cortex activation efficiency improved during a single session, but improvement in neural resource utilization, although significant, was attenuated in multiple sclerosis participants. These findings suggest encouraging brain adaptability in aging and neurological disease.

Fear of falling and common symptoms of multiple sclerosis: Physical function, cognition, fatigue, depression, and sleep - A systematic review

BACKGROUND

Fear of falling (FOF) is a common concern among persons with multiple sclerosis (MS) and affects the performance of their daily living activities. Falls may result in FOF, leading to worsening of symptoms of MS, physical deconditioning, and exposure to future falls. This may trigger a vicious cycle between FOF and falls. A better understanding of the relationship between FOF and symptoms of MS may be helpful to develop a conceptual model to guide fall prevention interventions.

OBJECTIVE

To synthesize the correlational and predictive relationships between FOF and common symptoms of MS.

METHODS

Databases including PubMed, Embase, Web of Science, Scopus, CINHAL, PsycINFO, and SPORTDiscuss were searched from inception to October 2023. Studies examining correlations and/or predictions between FOF and common MS symptoms that include measures of gait, postural control, fatigue, cognition, pain, sleep, depression, and anxiety were identified by two independent reviewers. Both reviewers also conducted the methodological quality assessment of the included studies.

RESULTS

Twenty-three studies with a total of 2819 participants were included in the review. Correlational findings indicated that increased FOF was significantly associated with greater walking deficits (lower gait speed, smaller steps), reduced mobility, and poorer balance. Increased FOF was also significantly correlated with higher cognitive impairments, more fatigue, sleep disturbances, and depression. Decreased gait parameters, reduced balance, lower physical functions, cognitive impairments, and sleep deficits were found as significant predictors of increased FOF.

CONCLUSION

Evidence indicates significant correlational and bidirectional predictive relationships exist between FOF and common MS symptoms. A comprehensive conceptual framework accounting for the interaction between FOF and MS symptoms is needed to develop effective falls prevention strategies.

Evaluating Cognitive-Motor Interference in Multiple Sclerosis: A Technology-Based Approach

BACKGROUND

People with multiple sclerosis (PwMS) frequently present both cognitive and motor impairments, so it is reasonable to assume they may have difficulties in executing dual-tasks (DT). The aim of the present study is to identify novel technology-based parameters to assess cognitive-motor interference (CMI) in PwMS. In particular, we focused on the definition of dual-task cost (DTC) measures using wearable and portable tools such as insoles and mobile apps.

METHODS

All participants underwent a verbal fluency task (cognitive single-task, ST), a motor ST of walking, and a combination of these tasks (DT). Number of words uttered in the cognitive ST and steps recorded by insoles were used to calculate the motor and cognitive DTC.

RESULTS

The number of steps strongly correlated with the walked meters for both single- (r = 0.88, p < 0.05) and dual- (r = 0.91, p < 0.05) tasks. Motor but not cognitive performances significantly worsened during DT. Over the cognitive ST and DT, the number of pronounced words progressively decreased, probably due to the activation of different cognitive processes. Cognitive efforts could be the cause of cognitive task prioritization.

CONCLUSIONS

Our findings promote the use of low-cost devices to assess CMI easily in the clinical context and to detect ecologically valid DT impairments.

Self-reported fatigue impact is associated with frequency of falls and injurious falls in people with multiple sclerosis

BACKGROUND

Fatigue is the most common symptom associated with multiple sclerosis (MS). Fatigue as a risk factor for injurious falls and frequency of falls is understudied. Falling recurrently is associated with injurious falls which may lead to reduced functional independence and poor quality of life of people with MS. Identifying contributors of recurrent falls and injurious falls is clinically useful to develop effective interventions.

OBJECTIVE

To investigate the associations between fatigue impact and frequency of falls and injurious falls in people with MS.

METHODS

Fifty-one participants completed the Modified Fatigue Impact Scale (MFIS) and a survey of number of falls and injurious falls during the past year. Logistic regression analyses were conducted to investigate whether scores on the MFIS (Total, Physical, Cognitive, and Psychosocial) predicted odds of being a recurrent faller (> 2 falls) or infrequent faller (1- 2 falls) versus a non-faller, and odds of experiencing an injurious fall (yes/no). The analyses were adjusted for demographic and clinical characteristics and common symptoms of MS (depression, cognition, pain, and sleep disturbance).

RESULTS

Higher MFIS Total score was associated with higher odds of infrequent falls (OR = 1.07, 95% CI, 1.00 - 1.15, p = 0.05) and recurrent falls (OR = 1.10, 95% CI, 1.00 - 1.20, p = 0.04) relative to not falling in the past year. Higher scores on the MFIS Physical subscale were significantly associated with high odds of infrequent falls (OR = 1.15, 95% CI, 1.02 - 1.30, p = 0.03) and recurrent falls (OR = 1.19, 95% CI, 1.02 - 1.39, p = 0.03). MFIS Psychosocial subscale was significantly associated with higher odds of infrequent falls (OR = 2.01, 95% CI, 1.14 - 3.53, p = 0.02). MFIS Total and MFIS Cognitive subscale were significantly associated with higher odds of injurious falls (OR = 1.11, 95% CI, 1.00 - 1.23, p = 0.04) and (OR = 1.28, 95% CI, 1.02 - 1.60, p = 0.04), respectively.

CONCLUSION

The findings indicated self-reported fatigue impact and its specific domains were associated with an increased risk of falling and injurious falls. Further studies using prospective falls assessment and longitudinal evaluation of fatigue are warranted to extend our findings.

Postural Control of Patients with Low Back Pain Under Dual-Task Conditions

Low back pain is a major global public health problem, but the current intervention effect is not ideal. A large body of previous literature suggests that patients with chronic low back pain may have abnormal postural control, which is more evident in the dual task situation. In recent years, research on postural control in patients with low back pain under dual-task conditions has gradually become a hot topic. However, the results obtained from these studies were not entirely consistent. In this review, we summarized relevant studies on the performance of postural control in patients with low back pain under dual-task conditions, analyze it from the perspective of the theoretical model of dual-task interaction, the specific research paradigm of dual task, the performance of postural control, and the related factors affecting postural control performance, etc. It was reasonable to assume that patients with low back pain might have a certain degree of abnormal postural control, and this abnormality was affected by comprehensive factors such as age, cognitive resource capacity, attention needs, complex sensorimotor integration, external environment, etc. Furthermore, postural control performance in low back pain patients under dual-task conditions was further influenced by the nature and complexity of the different tasks. In general, the more attention resources were needed, the external environmental conditions were worse, and the age-related functions were degenerate, etc., the weaker posture control ability was. In short, a deeper understanding of postural control in patients with low back pain under dual-task conditions may shed light on more references for the rehabilitation and management of low back pain, as well as some new ideas for scientific research on cognition and postural control.