Systematic review of the psychometric properties of balance measures for cerebellar ataxia

Effectiveness and cost of integrated cognitive and balance training for balance and falls in cerebellar ataxia: a blinded two-arm parallel group RCT

Background

In patients with cerebellar ataxia (CA), dual-tasking deteriorates the performance of one or both tasks.

Objective

Evaluate the effects of 4 weeks of cognitive-coupled intensive balance training (CIBT) on dual-task cost, dynamic balance, disease severity, number of falls, quality of life, cognition and cost among patients with CA.

Methods

This RCT compared CIBT (Group 1) to single-task training (Group 2) among 32 patients with CA. The intervention included either dual-task (CIBT) or single-task training for 4 weeks followed by 6 months of unsupervised home exercises. Dual-task timed up-and-go test (D-TUG) assessed dual-task cost of the physical and cognitive tasks. Assessment time points included baseline 1 (Week 0:T1), baseline 2 (Week 6:T2), post-intervention (Week 10:T3), and follow-up (Week 34:T4).

Results

Compared to single-task training CIBT improved the dual-task cost of physical task [MD -8.36 95% CI (-14.47 to -2.36, p < 0.01), dual-tasking ability [-6.93 (-13.16 to -0.70); p = 0.03] assessed using D-TUG, balance assessed using the scale for the assessment and rating of ataxia (SARAbal) [-2.03 (-4.04 to -0.19); p = 0.04], visual scores of the SOT (SOT-VIS) [-18.53 (-25.81 to -11.24, p ≤ 0.01] and maximal excursion [13.84 (4.65 to 23.03; p ≤ 0.01] of the Limits of Stability (LOS) in the forward direction and reaction time in both forward [-1.11 (-1.42 to -0.78); p < 0.01] and right [-0.18 (0.05 to 0.31); p < 0.01] directions following 4 weeks of training. CIBT did not have any additional benefits in reducing the number of falls, or improving disease severity, quality of life and cognition. The mean cost of intervention and healthcare costs for 7 months was HKD 33,380 for CIBT group and HKD 38,571 for single-task training group.

Conclusion

We found some evidence to support the use of CIBT for improving the dual-tasking ability, dual-task cost of physical task and dynamic balance in CA. Future large fully-powered studies are needed to confirm this claim.

Clinical trial registration

https://clinicaltrials.gov/study/NCT04648501, identifier [Ref: NCT04648501].

Efficacy of dual-task training on stability and function in children with ataxia after medulloblastoma resection: A randomized controlled trial

BACKGROUND/OBJECTIVE

In children, medulloblastoma (MB) is the most prevalent posterior fossa tumor. The first line of treatment is maximal safe resection. Therefore, symptoms of ataxia are commonly seen. Training the brain on balance and cognitive tasks makes balance more automatic than without cognitive tasks. The goal was to assess the effectiveness of dual-task practice on balance after MB excision in children with ataxia.

METHODS

Thirty children with ataxia after MB resection at Children Cancer Hospital Egypt were randomized into two equal groups. Exercises for mobility, balance, and gait training were given to both groups. The research group underwent a specific dual-task program (balance and cognitive). The program ran 3 days per week for 8 weeks. Children were evaluated before and after the treatment regimen using the Scale of Assessment and Rating of Ataxia (SARA), the HUMAC Balance System, Pediatric Balance Scale, and Functional Independent Measurement. All children's legal guardians signed an ethical agreement.

RESULTS

A notable improvement in balance was found in the dual group in Pediatric Balance Scale (PBS) (p = .028) and stability test (p = .0001) in favor of the study group. No discernible difference was observed in the Functional Independent Measurement score among the two groups (p = .158), although there was a statistically significant increase in both groups after treatment.

CONCLUSION

Dual-task program is more effective than traditional physical therapy alone in improving balance in children with ataxia after MB resection.

Identification of Gait Unbalance and Fallers Among Subjects with Cerebellar Ataxia by a Set of Trunk Acceleration-Derived Indices of Gait

This study aimed to assess the ability of 25 gait indices to characterize gait instability and recurrent fallers among persons with primary degenerative cerebellar ataxia (pwCA), regardless of gait speed, and investigate their correlation with clinical and kinematic variables. Trunk acceleration patterns were acquired during the gait of 34 pwCA, and 34 age- and speed-matched healthy subjects (HS_matched) using an inertial measurement unit. We calculated harmonic ratios (HR), percent recurrence, percent determinism, step length coefficient of variation, short-time largest Lyapunov exponent (sLLE), normalized jerk score, log-dimensionless jerk (LDLJ-A), root mean square (RMS), and root mean square ratio of accelerations (RMSR) in each spatial direction for each participant. Unpaired t-tests or Mann-Whitney tests were performed to identify significant differences between the pwCA and HS_matched groups. Receiver operating characteristics were plotted to assess the ability to characterize gait alterations in pwCA and fallers. Optimal cutoff points were identified, and post-test probabilities were calculated. The HRs showed to characterize gait instability and pwCA fallers with high probabilities. They were correlated with disease severity and stance, swing, and double support duration, regardless of gait speed. sLLEs, RMSs, RMSRs, and LDLJ-A were slightly able to characterize the gait of pwCA but failed to characterize fallers.

Validity of balance measures in cerebellar ataxia: A prospective study with 12-month follow-up

INTRODUCTION

Balance deficits are common in cerebellar ataxia. Determining which balance outcome measures are psychometrically strong for this population remains an unmet need.

OBJECTIVE

Evaluate the validity and responsiveness of two clinic-based balance measures [Berg Balance Scale (BBS) and balance sub-component of the Scale for the Assessment and Rating of Ataxia (SARA-bal)] and two laboratory-based balance measures [Sensory Organization Test (SOT) and Limits of Stability (LOS)] in cerebellar ataxia.

DESIGN

Prospective cohort study.

SETTING

Institutional study assessing 40 participants with cerebellar ataxia at baseline, 6, and 12 months.

MAIN OUTCOME MEASURES

Balance was assessed using the BBS, SARA-bal, SOT, and LOS; disease severity was assessed using the SARA; and Patients' Global Impression of Change (PGIC) was used to estimate responsiveness to disease progress at 6 and 12 months.

RESULTS

BBS and SARA-bal (Spearman's correlation coefficient, ρS = -0.89, p < 0.01) demonstrated strong criterion validity. Convergent validity was moderate to high (ρS range:-0.75 to 0.92) and external validity was low (ρS range:-0.75 to 0.11). Composite SOT scores (SOT-COM; ρS=0.29, p<0.01) and maximal excursion (MXE-LOS) in the forward (F) and right (R) directions of the LOS (ρS = 0.18, p < 0.01) demonstrated moderate to low criterion and convergent validity. The area under the receiver operating characteristic curve (AUC_ROC ) and its effect size (standard response mean [SRM]) for categorizing 'stable' and 'worsened' patients at 6 and 12 months were satisfactory for the BBS (AUC_ROC :0.75; SRM-Stable:1.06; SRM-Worsened:1.16), SARA-bal (AUC_ROC :0.76; SRM-Stable:0.86; SRM-Worsened:0.85), and MXE-LOS(R) (AUC_ROC :0.29; SRM-Stable:0.41; SRM-Worsened:1.39).

CONCLUSION

BBS and SARA-bal have moderate to strong criterion and convergent validity and adequate responsiveness to balance changes. Both laboratory-based measures (SOT and LOS) demonstrated a high floor effect. The SOT-COM and MXE-LOS(R) demonstrated moderate to low criterion validity, with only the MXE-LOS(R) displaying adequate responsiveness to balance changes after 6 and 12 months. This article is protected by copyright. All rights reserved.

Tai Chi for Dynamic Balance Training Among Individuals with Cerebellar Ataxia: An Assessor-Blinded Randomized-Controlled Trial

Objective: To evaluate the immediate and long-term effects of 12 weeks of Tai Chi training on dynamic balance and disease severity among individuals with cerebellar ataxia (CA).

Design: An assessor-blinded, two-arm, parallel-group randomized-controlled trial was conducted among 24 participants with CA. Participants were randomized to receive either Tai Chi intervention (n = 12) or usual care (n = 12). Dynamic balance was assessed using the Berg Balance Scale (BBS), Scale for the Assessment and Rating of Ataxia (SARA) balance sub-component of the SARA (SARAbal), Sensory Organization Test, and Limits of Stability test. Disease severity was assessed using the SARA and health-related quality of life using the EuroQol visual analog scale. Assessments were completed at baseline (week 0: T1), postintervention (week 12: T2), and at the end of the 24-week (week 36: T3) follow-up period.

Interventions: The 8-form Tai Chi exercise was delivered in 60-min sessions, three times a week for 12 weeks. Participants were asked to complete an unsupervised home Tai Chi exercise program over the next 24 weeks. Participants in the usual care control group completed all study measures but did not receive any intervention.

Results: Compared with the usual care control group, after 12 weeks of Tai Chi training, the experimental group demonstrated beneficial effects for dynamic balance assessed using the BBS (mean difference [MD]: 4, 95% confidence interval [CI]: −1.06 to 8.71) and the SARAbal (MD: −1.33, 95% CI: −2.66 to 2.33). The effect size ranged from small to large. The benefits gained were not sustained after 24 weeks during the follow-up assessment. Tai Chi did not benefit disease severity and health-related quality of life in this population.

Conclusion: Some evidence supports the immediate beneficial effects of 12 weeks of Tai Chi training on the dynamic balance among individuals with CA.

Australia New Zealand Clinical Trials Registry (ACTRN12617000327381).

Association of posturography with clinical measures in balance rehabilitation of ataxic patients

The assessment of balance includes posturography measures and clinical balance tests in individuals with ataxia. Although both advantages and disadvantages of these assessments have been stated, no relationship between them in individuals with ataxia has been shown in the literature. The aim of this cross-sectional study was to investigate the relationships between commonly used clinical balance tests and posturography measures in ataxic individuals. The study included a total of 42 patients (mean age: 33.90 ± 8.75 years) with different diagnoses causing ataxia. The sensory organization test (SOT), limits of stability (LOS), unilateral stance and rhythmic weight shift (RWS) tests in computerized dynamic posturography and the clinical balance tests of Berg Balance Scale (BBS), International Cooperative Ataxia Rating Scale (ICARS) and timed up and go (TUG) test were used to assess balance. The Spearman correlation test was used to evaluate the relationships between the clinical balance tests and posturography variables. Moderate and strong correlations were found between the ICARS, BBS and TUG scores and Unilateral Stance sway velocity, directional control parameter of RWS and LOS (P < 0.01-0.05). The ICARS and BBS scores were correlated with the SOT-Composite Equilibrium Score (P < 0.01-0.05). The results of this study suggest the use of both posturography and clinical balance tests in the rehabilitation of ataxic individuals with mild-moderate balance impairment, because posturography variables determine the underlying cause of imbalance and clinical tests evaluate balance in functional activities.

Developing a smartphone application, triaxial accelerometer-based, to quantify static and dynamic balance deficits in patients with cerebellar ataxias

BACKGROUND

Cerebellar ataxia is characterized by difficulty in the planning of movement and lack of anticipatory postural adjustments, which can result in deficits of balance. Being able to have quantitative measurements in clinical practice, to detect any improvements on balance resulting from new rehabilitation treatments or experimental drugs is very important.

AIM

The purpose of this study was to develop an application (APP) able to assess static and dynamic balance in patients with cerebellar ataxias (CA). The APP that works by a wearable device (smartphone) placed at the breastbone level and immobilized by an elastic band, measures the body sway by means of a triaxial accelerometer.

METHODS

We investigated 40 CA patients and 80 healthy subjects. All patients were clinically evaluated using the "Berg Balance Scale" (BBS) and the "Scale for the Assessment and Rating of Ataxia" (SARA). Balance impairment was quantitatively assessed using a validated static balance evaluating systems, i.e., Techno-body Pro-Kin footboard. All participants underwent static and dynamic balance assessments using the new APP.

RESULTS

We observed a strong correlation between the APP measurements and the score obtained with the BBS, SARA, and Pro-Kin footboard. The intra-rater reliability and the test-retest reliability of the APP measurements, estimated by intraclass correlation coefficient, were excellent. The standard error of measurement and the minimal detectable change were small. No learning effect was observed.

CONCLUSIONS

We can state that the APP is an easy, reliable, and valid evaluating system to quantify the trunk sway in a static position and during the gait.

Does integrated cognitive and balance (dual-task) training improve balance and reduce falls risk in individuals with cerebellar ataxia?

Frequent falls in people with cerebellar ataxia (CA) is a significant problem Therefore, an intervention that could improve balance and reduce the number of falls is of paramount importance from the patients' perspective. Combining cognitive training with physical training to improve balance is a new approach for reducing the risk of falls in patient populations who are at risk for falls. To determine if adding structured cognitive demands to conventional balance and coordination training we designed the Cognitive-coupled Intensive Balance Training (CIBT) program. We found that the more intensive and focused CIBT intervention reduced dual-task cost, improved balance, and reduced the number of falls in a sample of individuals with CA. We hypothesize that (1) CIBT will improve balance and reduce falls; and (2) CIBT will be a cost-effective treatment option for improving balance and reduce falls. To test these hypotheses, we propose conducting a randomized controlled trial (RCT) with economic evaluation . This paper reports the findings of our study testing the feasibility of the CIBT program, rationale for testing our hypothesis and an overview of our future study design to test the effectiveness and cost-effectiveness of the CIBT program.

Clinical assessment of balance using BBS and SARAbal in cerebellar ataxia: Synthesis of findings of a psychometric property analysis

Background

In the previous psychometric analysis paper in our series for identifying the core set of balance measures for the assessment of balance, we recommended the Berg Balance Scale (BBS) and balance sub-components of the Scale for the assessment and rating of ataxia (SARAbal) as psychometrically sound measures of balance for people with cerebellar ataxia (CA) secondary to multiple sclerosis.

Objective

The present study further examined the suitability of BBS and SARAbal for the assessment of balance in CA with regard to psychometric property strength, appropriateness, interpretability, precision, acceptability and feasibility.

Methods

Criteria to fulfill each factor was defined according to the framework of Fitzpatrick et al. (1998). Based on the findings of our previous psychometric analysis, each criterion was further analyzed.

Results

The psychometric analysis reported good reliability and validity estimates for the BBS and SARAbal recommending them as psychometrically sound measures; they fulfilled both criteria for appropriateness and interpretability, the measures showed evidence for precision and acceptability, and they were found to be feasible in terms of the time and cost involved for the balance assessment.

Conclusion

We have provided evidence for the use of the BBS and SARAbal for the assessment of balance among people with CA.

Relationship between subjective visual vertical and balance in individuals with multiple sclerosis

BACKGROUND

Subjective visual vertical (SVV) deviations have been correlated to abnormal cerebellar function in individuals diagnosed with multiple sclerosis (MS). It has been shown that individuals with MS have increased incidence of SVV abnormalities, yet this is not routinely tested in this population during physical therapy evaluation.

OBJECTIVE

This study aims to determine if there is a relationship between SVV and balance performance in people with MS who have cerebellar involvement. We hypothesize that individuals with greater SVV deviations will have worse balance performance.

METHODS

Fifteen females and five males (mean age 54.5 years [±7.03 SD]) with the diagnosis of MS and cerebellar involvement participated. Computerized SVV testing included rod and rod-and-frame conditions. None of the balance outcomes were correlated with the rod-only condition. Because there was a difference in magnitude of results within the rod-and-frame condition, based on whether the frame was rotated clockwise (CW) or counterclockwise (CCW), they were analysed independently.

RESULTS

For all six of the balance outcomes, there was a statistically significant moderate correlation with SVV deviations when the frame was tilted CCW: Barthel Index (r = -0.47, p = 0.018), Berg Balance Score (r = -0.59, p = 0.003), gait velocity (r = -0.52, p = 0.010), International Cooperative Ataxia Rating Scale (r = 0.56, p = 0.006), Scale for the Assessment and Rating of Ataxia (r = 0.62, p = 0.002), and Timed Up and Go (r = 0.58, p = 0.003). Interestingly, the Barthel Index was the only outcome that had statistical significance with a moderate correlation (r = -0.66, p = 0.001) when the frame was rotated CW. In this cohort, greater deviations during the rod-and-frame condition of SVV testing correlated with worse functional outcomes, especially when the frame was tilted CCW.

CONCLUSION

Individuals with MS who demonstrate decreased balance performance may rely more heavily on visual backgrounds. Implementation of SVV assessment for individuals with MS may provide clinicians with valuable information to identify clinical interventions.

Can pre-screening vestibulocerebellar involvement followed by targeted training improve the outcomes of balance in cerebellar ataxia?

Balance problems and frequent falls are common among clients with Cerebellar Ataxia (CA). CA is not a disease by itself but a collection of symptoms due to the involvement of cerebellum or its pathways. Presently the treatment for balance problems for CA is not standardized. Interventions available to improve balance are not specific to symptoms presentation. Functionally the cerebellum is divided into the spinocerebellum, vestibulocerebellum and corticocerebellum. Each functional zone has a distinct role in maintaining balance. Therefore, the presentation of symptoms will vary according to the functional zone involved. Pre-screening clients with CA for identifying the part of cerebellum involved will facilitate clinicians to provide tailor-made interventions for targeting specific symptoms for better outcomes. Pre-screening clients with CA according to the part of cerebellum involved is not in practice and our study will introduce this concept. We hypothesize pre-screening participants with spinocerebellar ataxia (SCA) for the involvement vestibulocerebellum followed by prescribing vestibulocerebellum targeted exercises will have better outcomes when compared to conventional balance training. We plan to conduct two related studies. In study 1 we will screen participants with CA for the involvement of vestibulocerebellum. In study 2, the effects of vestibulocerebellum targeted balance exercises on balance will be studied. We will assess the Subjective Visual Vertical (SVV) deviation and postural sway pattern to screen participants into people with and without vestibulocerebellar involvement. SVV deviation will be estimated using a computerized Subjective Visual Vertical (cSVV) device and postural sway pattern will be assessed using the limits of stability program of the Bertec© Balance system. The obtained SVV deviation scores will be used to derive at cut-off scores to discriminate clients with and without vestibulocerebellar involvement. The second study will test the treatment effects of conventional exercises plus vestibulocerebellum targeted exercises to improve balance by correcting SVV deviation in SCA with vestibulocerebellar involvement. The intervention is planned as 12 one-to-one sessions over three months period. Participants will be reassessed after the intervention and 3 months post-intervention. The findings of this cutting-edge research are extremely important to the clinicians, researchers and clients with SCA.

MRI-based cerebellar volume measurements correlate with the International Cooperative Ataxia Rating Scale score in patients with spinocerebellar degeneration or multiple system atrophy

BACKGROUND

Progression of clinical symptoms and cerebellar atrophy may vary among subtypes of spinocerebellar degeneration and multiple system atrophy. The aim of this cross-sectional study was to demonstrate the relationship between the International Cooperative Ataxia Rating Scale (ICARS) score and cerebellar volume derived from magnetic resonance imaging (MRI) in a broad spectrum of Japanese patients with cerebellar ataxia.

METHODS

A total of 86 patients with cerebellar ataxia (18 with cortical cerebellar atrophy, 34 with spinocerebellar ataxia, and 34 with multiple system atrophy) and 30 healthy subjects were studied. MRI-based cerebellar volume measurements were performed in all subjects using T1-weighted images acquired with a 1.5-T MRI scanner. The cerebellar volume/cranial anteroposterior (AP) diameter was used for statistical analysis.

RESULTS

Stepwise multiple regression analyses demonstrated that cerebellar volume/cranial AP diameter and midbrain AP/cranial AP diameter were significantly associated with the total score and domain I sub-score of ICARS. We found no interactions between these two anatomical factors in the ICARS total and domain I sub-scores. The main effects of these two predictors were statistically significant both in total and domain I sub-scores (p = 0.001 and 0.022, respectively).

CONCLUSIONS

Cerebellar volume and midbrain AP diameter normalized to the cranial AP diameter were significantly correlated with the ICARS total and domain I sub-scores. Further longitudinal studies are warranted to explore the role of these MRI biomarkers for predicting disease progression.

The quality of systematic reviews of health-related outcome measurement instruments

BACKGROUND

Systematic reviews of outcome measurement instruments are important tools for the selection of instruments for research and clinical practice. Our aim was to assess the quality of systematic reviews of health-related outcome measurement instruments and to determine whether the quality has improved since our previous study in 2007.

METHODS

A systematic literature search was performed in MEDLINE and EMBASE between July 1, 2013, and June 19, 2014. The quality of the reviews was rated using a study-specific checklist.

RESULTS

A total of 102 reviews were included. In many reviews the search strategy was considered not comprehensive; in only 59 % of the reviews a search was performed in EMBASE and in about half of the reviews there was doubt about the comprehensiveness of the search terms used for type of measurement instruments and measurement properties. In 41 % of the reviews, compared to 30 % in our previous study, the methodological quality of the included studies was assessed. In 58 %, compared to 55 %, the quality of the included instruments was assessed. In 42 %, compared to 7 %, a data synthesis was performed in which the results from multiple studies on the same instrument were somehow combined.

CONCLUSION

Despite a clear improvement in the quality of systematic reviews of outcome measurement instruments in comparison with our previous study in 2007, there is still room for improvement with regard to the search strategy, and especially the quality assessment of the included studies and the included instruments, and the data synthesis.

Gait and balance in adults with Friedreich's ataxia

Friedreich's ataxia (FA) is an autosomal recessive, neurodegenerative disease characterized by progressive muscle weakness and sensory loss, balance deficits, and gait ataxia. Gait and balance impairments become worse as the disease progresses, but limited research has quantitatively assessed these deficits in adults with FA. The purpose of this study was to analyze gait and balance in this population and investigate the relationship between these variables. Eight subjects with genetically confirmed FA (29.4±9.0 years) and eight healthy, matched control subjects (29.6±9.1 years) participated in this study. Spatiotemporal gait parameters were examined using the GAITRite Walkway System while balance was examined utilizing the Biodex Balance System SD and the Berg Balance Scale (BBS). The FA group exhibited approximately 50% slower gait velocity and 32% shorter step and stride lengths compared to the control group for both comfortable and fast walking (p<0.001). Further, stride length variability in the FA group was 3.4 and 2.7 times that of controls for comfortable and fast walking, respectively (p<0.01). Subjects with FA took 72% longer to complete the limits of stability (LOS) test and attained an overall directional control score that was 50% that of controls (p<0.05). Lastly, age at FA symptom onset correlated with stride length variability during fast walking (p<0.05), and BBS and LOS test scores correlated with stride length variability during both comfortable and fast walking (p<0.05). Results demonstrate that adults with FA have significantly impaired gait and balance and several measures of these impairments are correlated.