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

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.