scholarly journals Visual Feedback and Postural Control in Multiple Sclerosis

2020 ◽  
Vol 9 (5) ◽  
pp. 1291 ◽  
Author(s):  
Hernan Inojosa ◽  
Dirk Schriefer ◽  
Katrin Trentzsch ◽  
Antonia Klöditz ◽  
Tjalf Ziemssen
Keyword(s):  
Multiple Sclerosis ◽  
Postural Control ◽  
Visual Feedback ◽  
Repeated Measures ◽  
Preventive Measures ◽  
Clinical Importance ◽  
Disability Score ◽  
Average Speed ◽  
Static Posturography ◽  
The Difference

As people with multiple sclerosis (pwMS) manifest heterogeneous demyelinating lesions that could affect somatosensory or vestibular ways, visual stimulus as feedback could be especially relevant to achieve postural control. This has clinical importance for the development of preventive measures and rehabilitation therapies in order to avoid falls and accidents in this group. In our study, we objectively evaluated the influence of visual feedback on the stabilization of balance in pwMS versus healthy controls (HC) and its potential utility in clinical evaluation. Static posturography tests were performed in 99 pwMS and 30 HC. Subjects stood on a force platform with open and closed eyes. During this procedure, three balance parameters were obtained for both vision conditions: average sway, average speed, and average speed of sway. Neurostatus-Expanded Disease Disability Score (EDSS) and Multiple Sclerosis Functional Composite (MSFC) were performed in parallel as well. A two-way mixed repeated measures ANCOVA, controlling for sex and age, was performed to evaluate the effect of vision, MS diagnosis, and the interaction of both in static posturography parameters. The difference between both closed and open eyes conditions was calculated for each parameter and further analyzed according to MS-relevant clinical variables. The magnitude of the vision effect differed between pwMS and HC as a significant interaction between the vision and the MS diagnosis in the delineated area (p < 0.001) and average speed of sway (p = 0.001) was seen. These parameters had a greater increase in pwMS than in HC after closing eyes. For the average sway, a significant main effect of vision was present (p = 0.047). Additionally, the differences obtained between open and closed eyes conditions assessed with the delineated area and average speed of sway were moderately correlated to the assessed clinical tests EDSS (r = 0.405 and r = 0.329, respectively) and the MSFC (r = −0.385 and r = −0.259, respectively). In our study, pwMS were more dependent of visual feedback than HC to maintain postural control. This easy and short evaluation by static posturography could support the development of targeted preventive measures and interventions in pwMS.

scholarly journals Variability in Postural Control With and Without Balance-Based Torso- Weighting in People With Multiple Sclerosis and Healthy Controls

2014 ◽  
Vol 94 (10) ◽  
pp. 1489-1498 ◽  
Author(s):  
Charlotte M. Hunt ◽  
Gail Widener ◽  
Diane D. Allen
Keyword(s):  
Multiple Sclerosis ◽  
Postural Control ◽  
Repeated Measures ◽  
Center Of Pressure ◽  
Quiet Standing ◽  
Healthy Controls ◽  
Movement Variability ◽  
Lateral Direction ◽  
Eyes Closed ◽  
Eyes Open

Background People with multiple sclerosis (MS) have diminished postural control, and center of pressure (COP) displacement varies more in this population than in healthy controls. Balance-based torso-weighting (BBTW) can improve clinical balance and mobility in people with MS, and exploration using both linear and nonlinear measures of COP may help determine whether BBTW optimizes movement variability. Objective The aim of this study was to investigate the effects of BBTW on people with MS and healthy controls during quiet standing. Design This was a quasi-experimental study comparing COP variability between groups, between eye closure conditions, and between weighting conditions in the anterior-posterior and medial-lateral directions. Methods Twenty participants with MS and 18 healthy controls stood on a forceplate in 4 conditions: eyes open and closed and with and without BBTW. Linear measures of COP displacement included range and root mean square (RMS). Nonlinear measures included approximate entropy (ApEn) and Lyapunov exponent (LyE). Three-way repeated-measures analyses of variance compared measures across groups and conditions. The association between weighting response and baseline nonlinear variables was examined. When significant associations were found, MS subgroups were created and compared. Results The MS and control groups had significantly different range, RMS, and ApEn values. The eyes-open and eyes-closed conditions had significantly different range and RMS values. Change with weighting correlated with LyE (r=−.70) and ApEn (r=−.59). Two MS subgroups, with low and high baseline LyE values, responded to BBTW in opposite directions, with a significant main effect for weighting condition for the LyE variable in the medial-lateral direction. Limitations The small samples and no identification of impairments related to LyE at baseline were limitations of the study. Conclusions The LyE may help differentiate subgroups who respond differently to BBTW. In both subgroups, LyE values moved toward the average of healthy controls, suggesting that BBTW may help optimize movement variability in people with MS.

Stroboscopic Vision to Induce Sensory Reweighting During Postural Control

2017 ◽  
Vol 26 (5) ◽  
Author(s):  
Kyung-Min Kim ◽  
Joo-Sung Kim ◽  
Dustin R. Grooms
Keyword(s):  
Postural Control ◽  
Visual Feedback ◽  
Repeated Measures ◽  
Center Of Pressure ◽  
Somatosensory System ◽  
Lower Extremity Injury ◽  
Somatosensory Processing ◽  
Sensory Reweighting ◽  
Eyes Open ◽  
Almost All

Context: Patients with somatosensory deficits have been found to rely more on visual feedback for postural control. However, current balance tests may be limited in identifying increased visual dependence (sensory reweighting to the visual system), as options are typically limited to eyes open or closed conditions with no progressions between. Objective: To assess the capability of stroboscopic glasses to induce sensory reweighting of visual input during single-leg balance. Design:Descriptive Setting: Laboratory Participants: 18 healthy subjects without vision or balance disorders or lower extremity injury history (9 females; age = 22.1 ± 2.1 y; height = 169.8 ± 8.5 cm; mass = 66.5 ± 10.6 kg) participated. Interventions: Subjects performed 3 trials of unipedal stance for 10 s with eyes open (EO) and closed (EC), and with stroboscopic vision (SV) that was completed with specialized eyewear that intermittently cycled between opaque and transparent for 100 ms at a time. Balance tasks were performed on firm and foam surfaces, with the order randomized. Main Outcome Measures: Ten center-of-pressure parameters were computed. Results: Separate ANOVAs with repeated measures found significant differences between the 3 visual conditions on both firm (P-values =< .001) and foam (P-values =< .001 to .005) surfaces for all measures. For trials on firm surface, almost all measures showed that balance with SV was significantly impaired relative to EO, but less impaired than EC. On the foam surface, almost all postural stability measures demonstrated significant impairments with SV compared with EO, but the impairment with SV was similar to EC. Conclusions:SV impairment of single-leg balance was large on the firm surface, but not to the same degree as EC. However, the foam surface disruption to somatosensory processing and sensory reweighting to vision lead to greater disruptive effects of SV to the same level as EC. This indicates that when the somatosensory system is perturbed even a moderate decrease in visual feedback (SV) may induce an EC level impairment to postural control during single-leg stance.

Balance worsening associated with nabiximols in multiple sclerosis

2018 ◽  
Vol 25 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Letizia Castelli ◽  
Luca Prosperini ◽  
Carlo Pozzilli
Keyword(s):  
Multiple Sclerosis ◽  
Postural Control ◽  
Dual Task ◽  
Detrimental Effect ◽  
Stroop Test ◽  
Dual Task Condition ◽  
Static Posturography ◽  
Treatment Start ◽  
Task Conditions

We performed a dual-task experiment to explore the effect of nabiximols on postural control in 22 patients with multiple sclerosis. They were assessed with static posturography and Stroop test in single- and dual-task conditions at treatment start and after 1, 3 and 12 months. At follow-up, we found more impaired postural control in single-task ( F = 3.07, p = 0.044) and dual-task ( F = 4.90, p = 0.005) conditions in patients who continued treatment (continuers, n = 11) compared with those who discontinued (quitters, n = 11). Continuers were more impaired at Stroop test only in dual-task condition ( F = 3.17, p = 0.038). Our findings suggest that nabiximols had a detrimental effect on postural control, especially in multi-tasking conditions.

Validity of visual perceptive computing for static posturography in patients with multiple sclerosis

2016 ◽  
Vol 22 (12) ◽  
pp. 1596-1606 ◽  
Author(s):  
Janina R Behrens ◽  
Sebastian Mertens ◽  
Theresa Krüger ◽  
Anuschka Grobelny ◽  
Karen Otte ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Postural Control ◽  
Clinical Care ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Functional System ◽  
Microsoft Kinect ◽  
Maximum Speed ◽  
Static Posturography ◽  
Disability Status

Background: Multiple sclerosis (MS) patients frequently have postural control impairment but quantitative posturography is difficult to perform in clinical care. Recent technology facilitates new posturography approaches. Objective: To evaluate construct validity of visual perceptive computing (VPC) for static posturography to study postural control in MS patients. Methods: A total of 90 MS patients and 59 healthy controls (HCs) performed three stance tests: open, closed and tandem stance. Static posturography was performed using a VPC system with Microsoft Kinect. Clinical assessments included Expanded Disability Status Scale (EDSS), Timed-25-Foot-Walk, Short-Maximum-Speed-Walk and 12-item MS Walking Scale (MSWS-12) questionnaire. Reliability was assessed with intra-class correlation coefficients at retest. Results: As a group, MS patients performed worse than HCs in all tests. The closed stance test showed best applicability and reliability. With closed eyes, in 36.7% of patients, the three-dimensional mean angular sway velocity (MSV-3D) was above HCs’ 95th percentile. Higher MSV-3D was associated with decreased walking speed ( p < 0.001); worse clinical scores, mainly attributable to the cerebellar functional system score ( p < 0.001); and reflected in self-reported walking disability (MSWS-12, p < 0.001). Conclusion: Postural control can be reliably assessed by VPC-based static posturography in patients with MS. Abnormal postural control seems to predominantly reflect involvement of cerebellar circuits with impact on gait and walking disability.

Clinical and Serological Biomarkers of Treatment’s Response in Multiple Sclerosis Patients Treated Continuously with Interferonβ-1b for More than a Decade

2018 ◽  
Vol 17 (10) ◽  
pp. 780-792 ◽  
Author(s):  
Laura Iulia Bărcuţean ◽  
Andreea Romaniuc ◽  
Smaranda Maier ◽  
Zoltan Bajko ◽  
Anca Moţăţăianu ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Demographic Data ◽  
Active Form ◽  
Positive Influence ◽  
Serum Samples ◽  
Disability Score ◽  
Positive Correlations ◽  
Multiple Sclerosis Patients ◽  
Factor Α ◽  
Serological Biomarkers

Introduction: We evaluated the peripheral immune panel of Multiple Sclerosis (MS) patients treated for more than 10 years with interferon-beta1b (IFNβ-1b) and aimed to identify possible biomarkers of treatment response. Material and Methods: Serum samples from 70 MS patients treated with IFNβ-1b more than a decade were analysed for 15 cytokines, that were correlated with the disability score, annual relapse ratio (ARR): the total number of relapses-ARR_0, relapse on treatment-ARR_1 and demographic data. Two groups were defined based on the levels of disability, calculated using the Expanded Disability Status Scale (EDSS): G1 – recurrent-remissive and G2 – secondary-progressive. Furthermore, we split the patients based on gender (G1_f, G1_m, G2_f, G2_m). Results: The ARR was reduced after treatment was instituted. We found positive correlations between IL_25 and EDSS in G1_f and G2_f, tumor necrosis factor α (TNFα) and ARR_1 and ARR_0 in G1, and IL_17F with ARR_1. Negative correlations were for IL_25 and ARR_0 and ARR_1. SCD40L intensely positively correlated with IL_31 in G1 and G2. Conclusion: After more than a decade of treatment, IFNβ-1b offers good results by reducing relapses and slowing disability progression. Several biomarkers can be used to assess the patient’s response. High levels of IL_17 and TNFα will indicate a more active form of the disease. IL-25 may exert a positive influence in male MS patients and should be considered for future studies, together with the co-modulation between sCD40L and IL_31. Our method allowed us to screen the peripheral immune panel and can be used for assessing the peripheral levels of the above-mentioned cytokines.

scholarly journals Force Generation on the Hallux Is More Affected by the Ankle Joint Angle than the Lesser Toes: An In Vivo Human Study

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 48
Author(s):  
Junya Saeki ◽  
Soichiro Iwanuma ◽  
Suguru Torii
Keyword(s):  
Repeated Measures ◽  
Joint Angle ◽  
Plantar Flexion ◽  
Human Study ◽  
Force Generation ◽  
Functional Difference ◽  
Multiple Comparison Test ◽  
The Difference ◽  
Metatarsophalangeal Joints

The structure of the first toe is independent of that of the other toes, while the functional difference remains unclear. The purpose of this study was to investigate the difference in the force generation characteristics between the plantar-flexion of the first and second–fifth metatarsophalangeal joints (MTPJs) by comparing the maximal voluntary plantar-flexion torques (MVC torque) at different MTPJs and ankle positions. The MVC torques of the first and second–fifth MTPJs were measured at 0°, 15°, 30°, and 45° dorsiflexed positions of the MTPJs, and at 20° plantar-flexed, neutral, and 20° dorsiflexed positions of the ankle. Two-way repeated measures analyses of variance with Holm’s multiple comparison test (MTPJ position × ankle position) were performed. When the MTPJ was dorsiflexed at 0°, 15°, and 30°, the MVC torque of the first MTPJ when the ankle was dorsiflexed at 20° was higher than that when the ankle was plantar-flexed at 20°. However, the ankle position had no significant effect on the MVC torque of the second–fifth MTPJ. Thus, the MVC torque of the first MTPJ was more affected by the ankle position than the second–fifth MTPJs.

scholarly journals Bi-caudate ratio as a MRI marker of white matter atrophy in multiple sclerosis and ischemic leukocencephalopathy

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Dena Serag ◽  
Eman Ragab
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Surrogate Marker ◽  
Normal Subjects ◽  
Subjective Assessment ◽  
Linear Measurement ◽  
Control Group ◽  
Imaging Science ◽  
The Difference ◽  
Sensitivity Specificity

Abstract Background Brain atrophy measurement is now a cornerstone in basic neuro-imaging science. While assessment of white matter atrophy by visual inspection is subjective, volumetric approaches are time-consuming and not often feasible. Bi-caudate ratio represents a linear surrogate parameter of brain volume that can be derived from standard imaging sequences. This study highlights the value of the bi-caudate ratio (BCR) as a MRI marker of white matter atrophy in patients with multiple sclerosis and ischemic leukoencephalopathy and set a cut-off value to differentiate between patients with white matter atrophy and normal subjects. Results A total of 115 patients (54 males and 61 females) diagnosed with white matter leukoencephalopathy (MS in 51 patients and ischemic leukoencephalopathy in 64 patients) were included. Another group of 60 subjects with a normal white matter signal was recruited as a control group. BCR for the patient group ranged from 0.13 to 0.27 (mean (± SD) = 0.16 ± 0.02), while for the control group, it ranged from 0.05 mm to 0.13 (mean (± SD) = 0.09 ± 0.01). The difference between the two groups was statistically significant (P value < 0.001). A cut-off value of 0.13 was used to differentiate between the BCR in both patients and control groups with sensitivity, specificity, and accuracy of 99.2%, 100%, and 99%, respectively. The difference in BCR for patients diagnosed with MS and ischemic leukoencephalopathy was also statistically significant (P value < 0.001). Conclusion The bi-caudate ratio represents a linear measurement of subcortical atrophy that can be useful as a surrogate marker of global supra-tentorial white matter atrophy instead of the usually performed visual and therefore subjective assessment. It is an easily obtained measure that can be performed without complex time-consuming volumetric studies. Our findings also revealed that the BCR is higher in patients with ischemic leukoencephalopathy than in patients with MS.

scholarly journals Estimating and reporting treatment effects in clinical trials for weight management: using estimands to interpret effects of intercurrent events and missing data

2021 ◽  
Author(s):  
Sean Wharton ◽  
Arne Astrup ◽  
Lars Endahl ◽  
Michael E. J. Lean ◽  
Altynai Satylganova ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Missing Data ◽  
Weight Management ◽  
Treatment Effect ◽  
Repeated Measures ◽  
Treatment Effects ◽  
Randomized Clinical Trials ◽  
Weight Losses ◽  
The Difference ◽  
Treatment Of Obesity

AbstractIn the approval process for new weight management therapies, regulators typically require estimates of effect size. Usually, as with other drug evaluations, the placebo-adjusted treatment effect (i.e., the difference between weight losses with pharmacotherapy and placebo, when given as an adjunct to lifestyle intervention) is provided from data in randomized clinical trials (RCTs). At first glance, this may seem appropriate and straightforward. However, weight loss is not a simple direct drug effect, but is also mediated by other factors such as changes in diet and physical activity. Interpreting observed differences between treatment arms in weight management RCTs can be challenging; intercurrent events that occur after treatment initiation may affect the interpretation of results at the end of treatment. Utilizing estimands helps to address these uncertainties and improve transparency in clinical trial reporting by better matching the treatment-effect estimates to the scientific and/or clinical questions of interest. Estimands aim to provide an indication of trial outcomes that might be expected in the same patients under different conditions. This article reviews how intercurrent events during weight management trials can influence placebo-adjusted treatment effects, depending on how they are accounted for and how missing data are handled. The most appropriate method for statistical analysis is also discussed, including assessment of the last observation carried forward approach, and more recent methods, such as multiple imputation and mixed models for repeated measures. The use of each of these approaches, and that of estimands, is discussed in the context of the SCALE phase 3a and 3b RCTs evaluating the effect of liraglutide 3.0 mg for the treatment of obesity.

“Going Backward”: Effects of age and fatigue on posterior-directed falls in Parkinson disease

2021 ◽  
pp. 1-9
Author(s):  
Evan V. Papa ◽  
Rita M. Patterson ◽  
Nicoleta Bugnariu
Keyword(s):  
Postural Control ◽  
Parkinson Disease ◽  
Repeated Measures ◽  
Center Of Pressure ◽  
Angular Displacement ◽  
Reaction Times ◽  
Older Individuals ◽  
Peak Knee ◽  
Significant Difference ◽  
Fatiguing Exercise

BACKGROUND: Nearly half of persons with Parkinson disease (PD) report fatigue as a factor in their fall history. However, it is unknown whether these self-reported falls are caused by a sensation of fatigue or performance fatigue. OBJECTIVE: We sought to investigate the influences of performance fatigue and age on postural control in persons with PD. METHODS: Individuals with PD (n = 14) underwent postural control assessments before (T0) and immediately after (T1) fatiguing exercise. Biomechanical data were gathered on participants completing a treadmill-induced, posterior-directed fall. Performance fatigue was produced using lower extremity resistance exercise on an isokinetic ergometer. Repeated measures ANCOVAs were used with age as a covariate to determine the effects of performance fatigue on biomechanical variables. RESULTS: After adjustment for age, there was a statistically significant difference in peak center of pressure (COP) latency during the support phase of recovery. Pairwise comparisons demonstrated a decrease in peak ankle displacement from T0 to T1. Age was also found to be significantly related to reaction time and peak knee displacement while participants were fatigued. CONCLUSIONS: The decreased peak COP latency, along with decreased ankle angular displacement, suggest that persons with PD adopt a stiffening strategy in response to backward directed falls. Postural stiffening is not uncommon in persons with PD and could be a risk factor for falls. Older individuals with PD demonstrate slower mobility scores and decreased reaction times in the setting of fatigue, suggesting a combined effect of the aging and fatigue processes.

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