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.

Effects of therapeutic exercise on disease severity, balance, and functional Independence among individuals with cerebellar ataxia: A systematic review with meta-analysis

BACKGROUND

Balance impairments are common in cerebellar ataxia. Exercises are beneficial in this population.

OBJECTIVE

Explore the benefits of therapeutic exercises on disease severity, balance and functional independence in cerebellar ataxia.

METHODS

Databases were searched from inception until July 2021. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale and the Newcastle-Ottawa Scale (NOS); and quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool.

RESULTS

Twenty-six studies were included and eight studies of low to high PEDro methodological quality were meta-analyzed. 'Low' to 'moderate' GRADE quality evidence supports the use of therapeutic exercises to reduce disease severity, assessed using the Scale for the Assessment and Rating of Ataxia [weighted mean difference (WMD): -3.3; 95% confidence interval (95%CI): -3.7, -2.8; p < .01]; and improve balance, assessed using the Berg Balance Scale (WMD: 2.6; 95%CI: 1.1, 4.2; p < .01). The effect of therapeutic exercises on functional independence was insignificant (WMD: 1.6; 95%CI: -1.5, 4.6; p = .31).

CONCLUSION

Low to moderate evidence from studies of low to high methodological quality provides some support for therapeutic exercises for reducing disease severity among non-hereditary degenerative cerebellar ataxia and improving balance among acquired cerebellar ataxia. Exercises did not benefit functional independence. Additional studies of large sample size and high methodological quality are necessary to substantiate these findings.

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.

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.

Ankle positions potentially facilitating greater maximal contraction of pelvic floor muscles: a systematic review and meta-analysis

Objectives: To evaluate the effect of ankle positions on pelvic floor muscles in women. Methods: Multiple databases were searched from inception-July 2017. Study quality was rated using the grading of recommendations, assessment, development, and evaluation system and the "threats to validity tool". Results: Four studies were eligible for inclusion. Meta-analysis revealed significantly greater resting activity of pelvic floor muscles in neutral ankle position (-1.36 (95% CI -2.30, -0.42) p =  0.004) and induced 15° dorsiflexion (-1.65 (95% CI -2.49, -0.81) p =  0.0001) compared to induced 15° plantar flexion. Significantly greater maximal voluntary contraction of pelvic floor was found in dorsiflexion compared to plantar flexion (-2.28 (95% CI -3.96, -0.60) p =  0.008). Meta-analyses revealed no significant differences between the neutral ankle position and 15° dorsiflexion for either resting activity (0.30 (95% CI -0.75, 1.35) p =  0.57) or maximal voluntary contraction (0.97 (95% CI -0.77, 2.72) p =  0.27). Conclusion: Pelvic floor muscle-training for women with urinary incontinence could be performed in standing with ankles in a neutral position or dorsiflexion to facilitate greater maximal pelvic floor muscle contraction. As urethral support requires resting contraction of pelvic floor muscles, decreased resting activity in plantar flexion identified in the meta-analysis indicates that high-heel wearers with urinary incontinence might potentially experience more leakage during exertion in a standing position. Implications for rehabilitation Pooled analyses revealed that maximal voluntary contraction of pelvic floor muscle is greater in induced ankle dorsiflexion than induced plantar flexion. As pelvic floor muscle strengthening involves achieving a greater maximal voluntary contraction, pelvic floor muscle training for women with stress urinary incontinence could be performed in standing either with ankles in a neutral position or dorsiflexion. Decreased resting activity in plantar flexion identified in the meta-analysis indicates that high-heel wearers with stress urinary incontinence might potentially experience more leakage during exertion in a standing position. Women with stress urinary incontinence should be advised to wear flat shoes instead of high-heels and should be cautioned about body posture and ankle positions assumed during exercise and daily activities.