Validation of a next-generation sensory organization test in adults with and without vestibular dysfunction

Psychometric properties of the Mini-Balance Evaluation Systems Test and physical function measures in patients with Ehlers-Danlos syndrome/hypermobility spectrum disorders

PURPOSE

Ehlers-Danlos syndrome (EDS) and hypermobility spectrum disorders (HSD) are associated with impairments in balance and physical function. However, the psychometric properties of relevant outcome measures remain largely unexplored. The objectives of this study were to evaluate the construct validity of the Mini-Balance Evaluation Systems Test (Mini-BESTest) alongside the test-retest reliability of the Mini-BESTest, Six Minute Walk Test (6MWT), and Lower Extremity Functional Scale (LEFS) in patients with the hypermobility subtype of EDS (hEDS) and HSD.

MATERIALS AND METHODS

Participants with hEDS/HSD (n = 20) attended two visits scheduled one to two weeks apart. The construct validity of the Mini-BESTest was determined through Pearson correlations between force plate balance measures, 6MWT, and LEFS. Test-retest reliability of the measures was evaluated through intraclass correlation coefficients (ICC). Minimal detectable change values with 95% confidence (MDC95) were also calculated.

RESULTS

Mini-BESTest demonstrated significant correlations with force plate measures, 6MWT, and LEFS (r = -0.41 to 0.66). Test-retest reliability was excellent for the Mini-BESTest, 6MWT, and LEFS (ICC = 0.91 to 0.96). MDC95 was 4 for the Mini-BESTest, 77 m for the 6MWT, and 11 for the LEFS.

CONCLUSION

The Mini-BESTest is valid and reliable for assessing balance and mobility in patients with hEDS/HSD.IMPLICATIONS FOR REHABILITATIONThe Mini Balance Evaluation Systems Test (Mini-BESTest) is valid in capturing aspects of balance and physical function in patients with hypermobile Ehlers-Danlos syndrome or hypermobility spectrum disorders.However, the Mini-BESTest may show a potential ceiling effect for high functioning patients in this population.The Mini-BESTest, 6 Minute Walk Test, and the Lower Extremity Functional Scale also show excellent test-retest reliability in this population.The Minimal Detectable Change with 95% confidence intervals is 4 for the Mini-BESTest, 77 m for the 6 Minute Walk Test, and 11 for the Lower Extremity Functional Scale in this population.

Testing Dynamic Balance in People with Multiple Sclerosis: A Correlational Study between Standard Posturography and Robotic-Assistive Device

BACKGROUND

Robotic devices are known to provide pivotal parameters to assess motor functions in Multiple Sclerosis (MS) as dynamic balance. However, there is still a lack of validation studies comparing innovative technologies with standard solutions. Thus, this study's aim was to compare the postural assessment of fifty people with MS (PwMS) during dynamic tasks performed with the gold standard EquiTest® and the robotic platform hunova®, using Center of Pressure (COP)-related parameters and global balance indexes.

METHODS

Pearson's ρ correlations were run for each COP-related measure and the global balance index was computed from EquiTest® and hunova® in both open (EO) and closed-eyes (EC) conditions.

RESULTS

Considering COP-related parameters, all correlations were significant in both EO (0.337 ≤ ρ ≤ 0.653) and EC (0.344 ≤ ρ ≤ 0.668). Furthermore, Pearson's analysis of global balance indexes revealed relatively strong for visual and vestibular, and strong for somatosensory system associations (ρ = 0.573; ρ = 0.494; ρ = 0.710, respectively).

CONCLUSIONS

Findings confirm the use of hunova® as a valid device for dynamic balance assessment in MS, suggesting that such a robotic platform could allow for a more sensitive assessment of balance over time, and thus a better evaluation of the effectiveness of personalized treatment, thereby improving evidence-based clinical practice.

Postural control and trunk stability on sway parameters in adults with and without chronic low back pain

BACKGROUND

Postural sway changes often reflect functional impairments in adults with chronic low back pain (LBP). However, there is a gap in understanding how these individuals adapt their postural strategies to maintain stability.

PURPOSE

This study investigated postural sway distance and velocity, utilizing the center of pressure (COP) and center of gravity (COG), between adults with and without LBP during repeated unilateral standing trials.

METHODS

Twenty-six subjects with LBP and 39 control subjects participated in the study. Postural sway ranges, COP/COG sways, and sway velocities (computed by dividing path length by time in anteroposterior (AP) and mediolateral (ML) directions over 10 s) were analyzed across three unilateral standing trials.

RESULTS

A significant group interaction in sway range difference was observed following repeated trials (F = 5.90, p = 0.02). For COG sway range, significant group interactions were demonstrated in both directions (F = 4.28, p = 0.04) and repeated trials (F = 5.79, p = 0.02). The LBP group demonstrated reduced ML sway velocities in the first (5.21 ± 2.43 for the control group, 4.16 ± 2.33 for the LBP group; t = 1.72, p = 0.04) and second (4.87 ± 2.62 for the control group, 3.79 ± 2.22 for the LBP group; t = 1.73, p = 0.04) trials.

CONCLUSION

The LBP group demonstrated decreased ML sway velocities to enhance trunk stability in the initial two trials. The COG results emphasized the potential use of trunk strategies in augmenting postural stability and optimizing neuromuscular control during unilateral standing.

The psychometric properties of the modified fear of falling avoidance behavior questionnaire in Parkinson's disease and older adults

Introduction

The Fear of Falling Avoidance Behavior Questionnaire (FFABQ) has good psychometric properties. However, we have recently modified the FFABQ (mFFABQ) to improve the clarity of the questions and Likert responses. This study aimed to examine the reliability and validity of this modified version in older adults and people with Parkinson's disease (PD).

Methods

A total of 88 participants, 39 with PD (age = 72.2 ± 9.5; 29 males, 10 females) and 49 older adults (age = 72.8 ± 5.0; 13 males, 36 females), answered the mFFABQ twice, separated by 1 week, for test-retest reliability. Construct validity was evaluated through correlational analyses with fall history, Activities-Specific Balance Confidence Scale (ABC), Berg Balance Scale (BBS), Timed Up and Go, 30-Second Sit to Stand, Sensory Organization Test, Zung Anxiety Scale, Beck Depression Inventory, Consequences of Falling Questionnaire (CoFQ), and average daily activity levels using an activity monitor.

Results

The mFFABQ had good overall test-retest reliability (intraclass correlational coefficient [ICC] = 0.822; older adult ICC = 0.781, PD ICC = 0.806). The mFFABQ correlated with fall history (r = -0.430) and exhibited high correlation with the ABC (rho = -0.804) and moderate correlations with CoFQ (rho = 0.582) and BBS (rho = -0.595). The mFFABQ also correlated with time stepping (rho = -0.298) and number of steps (rho = -0.358).

Conclusion

These results provide supportive evidence for the reliability and validity of the mFFABQ in older adults and people with PD, which supports its suitability as a clinical and research tool for the assessment of fear of falling avoidance behavior.

NZ-RugbyHealth Study: Current Postural Control Ability of Former Rugby Union and Non-contact Sport Players

BACKGROUND

Players in contact sports frequently experience mild traumatic brain (concussion) injuries (TBI). While there are known disruptions to balance following acute head trauma, it is uncertain if sport-related concussion injuries have a lasting impact on postural control.

AIM

To assess postural control in retired rugby players in comparison to retired non-contact sport players, and to evaluate any association with self-reported sport-related concussion history.

METHODS

Using a cross-sectional design, 75 players in the NZ-RugbyHealth study from three sports groups (44 ± 8 years; 24 elite rugby, 30 community rugby, 21 non-contact sport) took part in this study. The SMART EquiTest® Balance Master was used to assess participant's ability to make effective use of visual, vestibular and proprioceptive information using standardised tests. Postural sway was also quantified using centre of pressure (COP) path length. The relationship among sports group, sport-related concussion history and postural control was evaluated using mixed regression models while controlling for age and body mass index.

RESULTS

Limited significant differences in balance metrics were found between the sports groups. A statistically significant (p < 0.001) interaction indicated a relationship between COP path length and sport-related concussion history in the most challenging balance condition, such that path length increased as the number of previous sport-related concussions increased.

CONCLUSION

There was some evidence for a relationship between sport-related concussion recurrence in sports players and postural stability in challenging balance conditions. There was no evidence of impaired balance ability in retired rugby players compared with non-contact sport athletes.

Standard versus innovative robotic balance assessment for people with multiple sclerosis: a correlational study

INTRODUCTION

Balance disorders are common in people with Multiple Sclerosis (PwMS) and, together with other impairments and disabilities, often prevent PwMS from performing their daily living activities. Besides clinical scales and performance tests, robotic platforms can provide more sensitive, specific, and objective monitoring. Validated technologies have been adopted as gold standard, but innovative robotic solutions would represent an opportunity to detect balance impairment in PwMS.

AIM

Study's aim was to compare postural assessment of 46 PwMS with a relapsing-remitting form during static tasks performed with the novel robotic platform hunova® and the gold standard EquiTest®, METHODS: Pearson's r was run on Center of Pressure (COP)-related parameters and global static balance measures computed from hunova® and EquiTest® in eyes-open (EO) and eyes-closed (EC) conditions. In addition, agreeableness level toward the use of both devices was tested through numeric rating scale.

RESULTS

Considering COP-related parameters, correlations were significant for all measures (p < .001). Interestingly, in EO, a strong correlation was shown for sway area (r = .770), while Medio-Lateral (ML) and Anterior-Posterior (AP) oscillation range, path length, ML and AP speed, ML and AP root mean square distance had a relatively strong association (.454 ≤ r ≤ .576). In EC, except for ML oscillation range showing a relatively strong correlation (r = .532), other parameters were strongly associated (.603 ≤ r ≤ .782). Correlations between global balance indexes of hunova® and EquiTest® revealed a relatively strong association between the Somatosensory Score in EquiTest® and the Somatosensory Index in hunova® (r = - .488). While in EO Static Balance Index from hunova® was highly correlated with Equilibrium score of EquiTest® (r = .416), Static Balance Index had a relatively strong association with both the Equilibrium (r = .482) and Strategy Score (r = .583) of EquiTest® in EC. Results from agreeableness rating scale revealed that hunova® was highly appreciated compared to EquiTest® (p = .044).

CONCLUSIONS

hunova® represents an innovative adjunct to standard robotic balance evaluation for PwMS. This confirms that combining traditional and robotic assessments can more accurately detect balance impairments in MS.

Estimation of the visual contribution to standing balance using virtual reality

Sensory perturbations are a valuable tool to assess sensory integration mechanisms underlying balance. Implemented as systems-identification approaches, they can be used to quantitatively assess balance deficits and separate underlying causes. However, the experiments require controlled perturbations and sophisticated modeling and optimization techniques. Here we propose and validate a virtual reality implementation of moving visual scene experiments together with model-based interpretations of the results. The approach simplifies the experimental implementation and offers a platform to implement standardized analysis routines. Sway of 14 healthy young subjects wearing a virtual reality head-mounted display was measured. Subjects viewed a virtual room or a screen inside the room, which were both moved during a series of sinusoidal or pseudo-random room or screen tilt sequences recorded on two days. In a between-subject comparison of 10 [Formula: see text] 6 min long pseudo-random sequences, each applied at 5 amplitudes, our results showed no difference to a real-world moving screen experiment from the literature. We used the independent-channel model to interpret our data, which provides a direct estimate of the visual contribution to balance, together with parameters characterizing the dynamics of the feedback system. Reliability estimates of single subject parameters from six repetitions of a 6 [Formula: see text] 20-s pseudo-random sequence showed poor test-retest agreement. Estimated parameters show excellent reliability when averaging across three repetitions within each day and comparing across days (Intra-class correlation; ICC 0.7-0.9 for visual weight, time delay and feedback gain). Sway responses strongly depended on the visual scene, where the high-contrast, abstract screen evoked larger sway as compared to the photo-realistic room. In conclusion, our proposed virtual reality approach allows researchers to reliably assess balance control dynamics including the visual contribution to balance with minimal implementation effort.

The "vestibular neuromatrix": A proposed, expanded vestibular network from graph theory in post-concussive vestibular dysfunction

Convergent clinical and neuroimaging evidence suggests that higher vestibular function is subserved by a distributed network including visuospatial, cognitive-affective, proprioceptive, and integrative brain regions. Clinical vestibular syndromes may perturb this network, resulting in deficits across a variety of functional domains. Here, we leverage structural and functional neuroimaging to characterize this extended network in healthy control participants and patients with post-concussive vestibular dysfunction (PCVD). Then, 27 healthy control subjects (15 females) and 18 patients with subacute PCVD (12 female) were selected for participation. Eighty-two regions of interest (network nodes) were identified based on previous publications, group-wise differences in BOLD signal amplitude and connectivity, and multivariate pattern analysis on affective tests. Group-specific "core" networks, as well as a "consensus" network comprised of connections common to all participants, were then generated based on probabilistic tractography and functional connectivity between the 82 nodes and subjected to analyses of node centrality and community structure. Whereas the consensus network was comprised of affective, integrative, and vestibular nodes, PCVD participants exhibited diminished integration and centrality among vestibular and affective nodes and increased centrality of visual, supplementary motor, and frontal and cingulate eye field nodes. Clinical outcomes, derived from dynamic posturography, were associated with approximately 62% of all connections but best predicted by amygdalar, prefrontal, and cingulate connectivity. No group-wise differences in diffusion metrics or tractography were noted. These findings indicate that cognitive, affective, and proprioceptive substrates contribute to vestibular processing and performance and highlight the need to consider these domains during clinical diagnosis and treatment planning.

Vestibular contributions to the Romberg test: Testing semicircular canal and otolith function

Normal stance relies on three sensory inputs: vision, proprioception and vestibular function. The Romberg test, trying to stand with feet together and eyes closed, is familiar to every medical student as a test of distal proprioceptive impairment. It remains the best known of Romberg's many remarkable contributions to clinical neurology. In Romberg's time almost nothing was known about the function of the vestibular system. We now know that standing with the eyes closed on a compliant rather than a firm surface is more a test of vestibular than proprioceptive function. Peripheral vestibular function tests in clinical use today all rely on measurements of oligosynaptic brainstem reflexes. Short-latency eye rotations in response to rapid, brief head rotations (head impulses) give an accurate, robust and reproducible measure of the function of any and each of the six semicircular canals. Short-latency evoked potentials from sternomastoid and inferior oblique muscles in response to loud clicks or skull taps (vestibular evoked myogenic potentials) give an accurate and reproducible measure of the function of each and any of the four otolith organs. In the present paper, we briefly review what is now known about the anatomy and physiology of the peripheral receptors and brainstem pathways mediating these reflexes and examine how this knowledge can help interpret the Romberg test.