'Timed up and go' and brain atrophy: a preliminary MRI study to assess functional mobility performance in multiple sclerosis

Links between Neuroanatomy and Neurophysiology with Turning Performance in People with Multiple Sclerosis

Multiple sclerosis is accompanied by decreased mobility and various adaptations affecting neural structure and function. Therefore, the purpose of this project was to understand how motor cortex thickness and corticospinal excitation and inhibition contribute to turning performance in healthy controls and people with multiple sclerosis. In total, 49 participants (23 controls, 26 multiple sclerosis) were included in the final analysis of this study. All participants were instructed to complete a series of turns while wearing wireless inertial sensors. Motor cortex gray matter thickness was measured via magnetic resonance imaging. Corticospinal excitation and inhibition were assessed via transcranial magnetic stimulation and electromyography place on the tibialis anterior muscles bilaterally. People with multiple sclerosis demonstrated reduced turning performance for a variety of turning variables. Further, we observed significant cortical thinning of the motor cortex in the multiple sclerosis group. People with multiple sclerosis demonstrated no significant reductions in excitatory neurotransmission, whereas a reduction in inhibitory activity was observed. Significant correlations were primarily observed in the multiple sclerosis group, demonstrating lateralization to the left hemisphere. The results showed that both cortical thickness and inhibitory activity were associated with turning performance in people with multiple sclerosis and may indicate that people with multiple sclerosis rely on different neural resources to perform dynamic movements typically associated with fall risk.

Wearable Sensor Technologies to Assess Motor Functions in People With Multiple Sclerosis: Systematic Scoping Review and Perspective

BACKGROUND

Wearable sensor technologies have the potential to improve monitoring in people with multiple sclerosis (MS) and inform timely disease management decisions. Evidence of the utility of wearable sensor technologies in people with MS is accumulating but is generally limited to specific subgroups of patients, clinical or laboratory settings, and functional domains.

OBJECTIVE

This review aims to provide a comprehensive overview of all studies that have used wearable sensors to assess, monitor, and quantify motor function in people with MS during daily activities or in a controlled laboratory setting and to shed light on the technological advances over the past decades.

METHODS

We systematically reviewed studies on wearable sensors to assess the motor performance of people with MS. We scanned PubMed, Scopus, Embase, and Web of Science databases until December 31, 2022, considering search terms "multiple sclerosis" and those associated with wearable technologies and included all studies assessing motor functions. The types of results from relevant studies were systematically mapped into 9 predefined categories (association with clinical scores or other measures; test-retest reliability; group differences, 3 types; responsiveness to change or intervention; and acceptability to study participants), and the reporting quality was determined through 9 questions. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) reporting guidelines.

RESULTS

Of the 1251 identified publications, 308 were included: 176 (57.1%) in a real-world context, 107 (34.7%) in a laboratory context, and 25 (8.1%) in a mixed context. Most publications studied physical activity (196/308, 63.6%), followed by gait (81/308, 26.3%), dexterity or tremor (38/308, 12.3%), and balance (34/308, 11%). In the laboratory setting, outcome measures included (in addition to clinical severity scores) 2- and 6-minute walking tests, timed 25-foot walking test, timed up and go, stair climbing, balance tests, and finger-to-nose test, among others. The most popular anatomical landmarks for wearable placement were the waist, wrist, and lower back. Triaxial accelerometers were most commonly used (229/308, 74.4%). A surge in the number of sensors embedded in smartphones and smartwatches has been observed. Overall, the reporting quality was good.

CONCLUSIONS

Continuous monitoring with wearable sensors could optimize the management of people with MS, but some hurdles still exist to full clinical adoption of digital monitoring. Despite a possible publication bias and vast heterogeneity in the outcomes reported, our review provides an overview of the current literature on wearable sensor technologies used for people with MS and highlights shortcomings, such as the lack of harmonization, transparency in reporting methods and results, and limited data availability for the research community. These limitations need to be addressed for the growing implementation of wearable sensor technologies in clinical routine and clinical trials, which is of utmost importance for further progress in clinical research and daily management of people with MS.

TRIAL REGISTRATION

PROSPERO CRD42021243249; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=243249.

Efficacy of Tai Chi on lower limb function of Parkinson's disease patients: A systematic review and meta-analysis

Background

At present, the effect of Tai Chi (TC) on lower limb function in patients with Parkinson's disease (PD) is controversial. Therefore, we conducted a meta-analysis on the influence of TC on lower limb function in PD patients.

Methods

According to the PRISMA guidelines, seven databases were searched. Randomized controlled trials (RCTS) were selected and screened according to inclusion and exclusion criteria. We assessed the quality of the studies using the Cochrane Risk of Bias tool and then extracted the characteristics of the included studies. The random effect model was adopted, and heterogeneity was measured by I ² statistic.

Results

A total of 441 articles were screened, and 10 high-quality RCTs were with a total of 532 patients with PD met Our inclusion criteria. Meta-analysis showed that compared To control groups TC improved several outcomes. TC significantly improved motor function (SMD = -0.70; 95% CI = -0.95, -0.45; p < 0.001; I ² = 35%), although The results were not statistically significant for The subgroup analysis of TC duration (SMD = -0.70; 95% CI = -0.95, -0.45; p = 0.88; I ² = 0%;). TC significantly improved balance function (SMD = 0.89; 95% CI = 0.51, 1.27; p < 0.001; I ² = 54%), functional walking capacity (SMD = -1.24; 95% CI = -2.40, -0.09; p = 0.04; I ² = 95%), and gait velocity (SMD = 0.48; 95% CI = -0.02, 0.94; p = 0.04; I ² = 78%), But Did Not improve endurance (SMD = 0.31; 95% CI = -0.12, 0.75; p = 0.16; I ² = 0%), step length (SMD = 0.01; 95% CI = -0.34, 0.37; p = 0.94; I ² = 29%), and cadence (SMD = 0.06; 95% CI = -0.25, 0.36; p = 0.70; I ² = 0%).

Conclusion

TC has beneficial effects on motor function, balance function, functional walking ability, and gait velocity, but does not improve walking endurance, stride length, and cadence.

Individual differences in visual evoked potential latency are associated with variance in brain tissue volume in people with multiple sclerosis: An analysis of brain function-structure correlates

Visual evoked potentials (VEP) index visual pathway functioning, and are often used for clinical assessment and as outcome measures in people with multiple sclerosis (PwMS). VEPs may also reflect broader neural disturbances that extend beyond the visual system, but this possibility requires further investigation. In the present study, we examined the hypothesis that delayed latency of the P100 component of the VEP would be associated with broader structural changes in the brain in PwMS. We obtained VEP latency for a standard pattern-reversal checkerboard stimulus paradigm, in addition to Magnetic Resonance Imaging (MRI) measures of whole brain volume (WBV), gray matter volume (GMV), white matter volume (WMV), and T2-weighted fluid attenuated inversion recovery (FLAIR) white matter lesion volume (FLV). Correlation analyses indicated that prolonged VEP latency was significantly associated with lower WBV, GMV, and WMV, and greater FLV. VEP latency remained significantly associated with WBV, GMV, and WMV even after controlling for the variance associated with inter-ocular latency, age, time between VEP and MRI assessments, and other MRI variables. VEP latency delays were most pronounced in PwMS that exhibited low volume in both white and gray matter simultaneously. Furthermore, PwMS that had delayed VEP latency based on a clinically relevant cutoff (VEP latency ≥ 113 ms) in both eyes had lower WBV, GMV, and WMV and greater FLV in comparison to PwMS that had normal VEP latency in one or both eyes. The findings suggest that PwMS that have delayed latency in both eyes may be particularly at risk for exhibiting greater brain atrophy and lesion volume. These analyses also indicate that VEP latency may index combined gray matter and white matter disturbances, and therefore broader network connectivity and efficiency. VEP latency may therefore provide a surrogate marker of broader structural disturbances in the brain in MS.

Turning and multitask gait unmask gait disturbance in mild-to-moderate multiple sclerosis: Underlying specific cortical thinning and connecting fibers damage

Multiple sclerosis (MS) causes gait and cognitive impairments that are partially normalized by compensatory mechanisms. We aimed to identify the gait tasks that unmask gait disturbance and the underlying neural correlates in MS. We included 25 patients with MS (Expanded Disability Status Scale score: median 2.0, interquartile range 1.0-2.5) and 19 healthy controls. Fast-paced gait examinations with inertial measurement units were conducted, including straight or circular walking with or without cognitive/motor tasks, and the timed up and go test (TUG). Receiver operating characteristic curve analysis was performed to distinguish both groups by the gait parameters. The correlation between gait parameters and cortical thickness or fractional anisotropy values was examined by using three-dimensional T1-weighted imaging and diffusion tensor imaging, respectively (corrected p < .05). Total TUG duration (>6.0 s, sensitivity 88.0%, specificity 84.2%) and stride velocity during cognitive dual-task circular walking (<1.12 m/s, 84.0%, 84.2%) had the highest discriminative power of the two groups. Deterioration of these gait parameters was correlated with thinner cortical thickness in regional areas, including the left precuneus and left temporoparietal junction, overlapped with parts of the default mode network, ventral attention network, and frontoparietal network. Total TUG duration was negatively correlated with fractional anisotropy values in the deep cerebral white matter areas. Turning and multitask gait may be optimal to unveil partially compensated gait disturbance in patients with mild-to-moderate MS through dynamic balance control and multitask processing, based on the structural damage in functional networks.

Physical function, an adjunct to brain health score for phenotyping cognitive function trajectories in older age: Findings from the Irish Longitudinal Study on Ageing (TILDA)

BACKGROUND

Evidence is limited regarding the cumulative effect of risk factors on cognitive decline and the added value of physical function for cognitive function trajectory stratification. We operationalise thirteen modifiable dementia risk factors in a scoring system and investigate the relationship between this brain health score, combined with simple measures of physical function, and risk of cognitive decline.

METHODS

Population-based cohort study of persons aged 50+ from the Irish Longitudinal Study on Ageing without a history of dementia at baseline who underwent repeated neuropsychological tests (8.08±0.3 year follow-up) were included in the analyses. Exposures were the number of brain health metrics (defined by the Lancet Commission on Dementia Prevention, Intervention and Care report) at recommended optimal levels. Physical function exposures included Timed Up and Go, dual-task walking speed and grip strength. Each health metric and physical function measure at the recommended level was assigned a value of 1 and combined to generate brain health scores. Relationship with group-based trajectories of global cognitive function (multi-domains composite score), estimated using K-means for Longitudinal data, were assessed via ordinal logistic regressions.

RESULTS

Among 2,327 participants (mean age, 61 years; 54% women), each additional optimal metric on the brain health score (Odds 0.67 [0.62;0.73]) was associated with reduced odds of cognitive decline. Adding Timed-Up and Go (Odds 0.71 [0.59;0.84]) and Dual-task walking speed (Odds 0.74 [0.63;0.89]) further improved model fit (ΔAIC=14.8).

CONCLUSIONS

These findings support the promotion and maintenance of physical function in addition to brain health strategies to reduce risk of cognitive decline.

Cognitive Function and Whole-Brain MRI Metrics Are Not Associated with Mobility in Older Adults with Multiple Sclerosis

Due to advances in disease-modifying medications and earlier management of comorbidities, adults with multiple sclerosis (MS) are living longer, and this coincides with the aging of the general population. One major problem among older adults with and without MS is limited mobility, a consequence of aging that often negatively affects quality of life. Identifying factors that contribute to mobility disability is needed to develop targeted rehabilitation approaches. This study examined cognitive processing speed and global brain atrophy as factors that may contribute to mobility disability in older adults with and without MS. Older adults (≥55 years) with MS (n = 31) and age- and sex-matched controls (n = 22) completed measures of mobility (Short Physical Performance Battery) and cognitive processing speed (Symbol Digit Modalities Test) and underwent an MRI to obtain whole-brain metrics (gray matter volume, white matter volume, ventricular volume) as markers of atrophy. Mobility was significantly worse in the MS group than in the control group (p = 0.004). Spearman correlations indicated that neither cognitive processing speed (MS: r_s = 0.26; Control: r_s = 0.08) nor markers of global brain atrophy (MS: r_s range = −0.30 to −0.06; Control: r_s range = −0.40 to 0.16) were significantly associated with mobility in either group. Other factors such as subcortical gray matter structures, functional connectivity, exercise/physical activity, and cardiovascular fitness should be examined as factors that may influence mobility in aging adults with and without MS.

Serum neurofilament light chains in MS: Association with the Timed Up and Go

OBJECTIVE

This cross-sectional study aims to assess the association between neuroaxonal damage assessed by serum neurofilament light chain (sNfL) and the Timed Up and Go (TUG)-a reliable and rapid measure of global neurologic disability-in patients with MS.

METHODS

A total of 41 consecutive patients with MS (38.0 ± 10.4 years; 57% women) with low level of disability (Expanded Disability Status Scale [EDSS] score 0-3) (EDSS score 1.0, interquartile range [IQR] 0.0-2.0) were included in this study. The TUG and sNfL were measured in a 6-month interval, together with a comprehensive neuropsychological and quantitative gait evaluation. The association of sNfL (dependant variable) with TUG, and other gait, cognitive, and behavioral measures (independent variables) were evaluated with multiple linear regressions adjusted for age, sex, and EDSS score.

RESULTS

The sNfL concentration was 23.51 pg/mL (IQR 16.51-32.21 pg/mL), and the mean TUG was 9.27 ± 1.70 seconds. Only the TUG was associated with sNfL (β = 0.021; 95% CI 0.003-0.037; p = 0.022) (after adjusting for age, sex, and EDSS score), whereas this was not the case for gait and neuropsychological measures.

CONCLUSIONS

The TUG-an easy and unexpansive measure of disability-is associated with the degree of neuroaxonal damage, as measured by sNfL, in patients with MS with low level of disability. These findings confirm the validity of the TUG as a reliable bedside measure of global neurologic disability as a result of neuroaxonal damage.

Association between brain atrophy and cognitive motor interference in multiple sclerosis

INTRODUCTION

Cognitive motor interference (CMI) is performance impairment due to simultaneuous task execution and is measured using the dual task cost (DTC). No pathological feature of MS has to date been associated with CMI.

AIM

To assess the relationship between brain volumes and CMI, as measured using the DTC, in a cross-sectional study.

METHODS

A group of persons with MS (pwMS) and an age- and sex-matched healthy control (HC) group underwent 3D gait analysis during using the dual task paradigm. Brain volumes were measured on T1-weighted gradient echo scans using SIENAX software. The relationships between brain volumes and the DTCs of spatial temporal parameters were evaluated using Pearson correlation. A multiple regression model was used to evaluate the ability to predict the DTC of cadence based on brain volume and grey matter (GM) volume.

RESULTS

Forty-four patients and 16 HCs underwent MRI and gait analysis. The mean expanded disability status scale (EDSS) was 2.4 ± 1.5. Significant relationships between brain volumes and DTC were found only in the pwMS group, with higher rho scores for the DTC of mean velocity, DTC of cadence, and DTC of stride time. A statistically significant regression equation with an R² value of 0.684 was found using GM and Z-score on the Stroop test as predictors of the DTC of cadence (p < 0.001).

CONCLUSION

Brain atrophy, especially than in the GM, is a major determinant of DTC, although other pathological markers also contribute to CMI in patients with MS.

The physical capabilities underlying timed "Up and Go" test are time-dependent in community-dwelling older women

Timed 'Up and Go' (TUG) has been widely used in research and clinical practice to evaluate physical function and mobility in older adults. However, the physical capabilities underlying TUG performance are not well elucidated. Therefore, the present study aimed at investigating a selection of physical capacities underlying TUG performance in community-dwelling older women. Four hundred and sixty-eight apparently healthy older women independent to perform the activities of daily living (mean age: 65.8 ± 6.0 years) were recruited from two specialized healthcare centers for older adults to participate in the study. Volunteers had their medical books reviewed and underwent evaluations of anthropometric data as well as physical and functional capacities. Pearson's correlation results indicate that TUG performance was significantly associated with upper (i.e., handgrip strength) and lower (i.e., sit-to-stand) limb muscle strength, balance (i.e., one-leg stand), lower limb muscle power (i.e., countermovement jump), aerobic capacity (i.e., 6-minute walk test), and mobility (i.e., usual and maximal walking speeds). When the analyses were performed based on TUG quartiles, a larger number of physical capabilities were associated with TUG >75% in comparison with TUG <25%. Multiple linear regression results indicate that the variability in TUG (~20%) was explained by lower limb muscle strength (13%) and power (1%), balance (4%), mobility (2%), and aerobic capacity (<1%), even after adjusted by age and age plus body mass index (BMI). However, when TUG results were added as quartiles, a decrease in the impact of physical capacities on TUG performance was determined. As a whole, our findings indicate that the contribution of physical capabilities to TUG performance is altered according to the time taken to perform the test, so that older women in the lower quartiles - indicating a higher performance - have an important contribution of lower limb muscle strength, while volunteers in the highest quartile demonstrate a decreased dependence on lower limb muscle strength and an increased contribution of other physical capabilities, such as lower limb muscle power and balance.