Digital Gait Measures Capture 1-Year Progression in Early-Stage Spinocerebellar Ataxia Type 2.

BACKGROUND: With disease-modifying drugs in reach for cerebellar ataxias, fine-grained digital health measures are highly warranted to complement clinical and patient-reported outcome measures in upcoming treatment trials and treatment monitoring. These measures need to demonstrate sensitivity to capture change, in particular in the early stages of the disease. OBJECTIVE: Our aim is to unravel gait measures sensitive to longitudinal change in the-particularly trial-relevant-early stage of spinocerebellar ataxia type 2 (SCA2). METHODS: We performed a multicenter longitudinal study with combined cross-sectional and 1-year interval longitudinal analysis in early-stage SCA2 participants (n = 23, including nine pre-ataxic expansion carriers; median, ATXN2 CAG repeat expansion 38 ± 2; median, Scale for the Assessment and Rating of Ataxia [SARA] score 4.8 ± 4.3). Gait was assessed using three wearable motion sensors during a 2-minute walk, with analyses focused on gait measures of spatio-temporal variability that have shown sensitivity to ataxia severity (eg, lateral step deviation). RESULTS: We found significant changes for gait measures between baseline and 1-year follow-up with large effect sizes (lateral step deviation P = 0.0001, effect size rprb = 0.78), whereas the SARA score showed no change (P = 0.67). Sample size estimation indicates a required cohort size of n = 43 to detect a 50% reduction in natural progression. Test-retest reliability and minimal detectable change analysis confirm the accuracy of detecting 50% of the identified 1-year change. CONCLUSIONS: Gait measures assessed by wearable sensors can capture natural progression in early-stage SCA2 within just 1 year-in contrast to a clinical ataxia outcome. Lateral step deviation represents a promising outcome measure for upcoming multicenter interventional trials, particularly in the early stages of cerebellar ataxia. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Association between superior longitudinal fasciculus, motor recovery, and motor outcome after stroke: a cohort study.

Introduction: Parieto-frontal interactions are mediated by the superior longitudinal fasciculus (SLF) and are crucial to integrate visuomotor information and mediate fine motor control. In this study, we aimed to characterize the relation of white matter integrity of both parts of the SLF (SLF I and SLF II) to both motor outcome and recovery and its evolution over time in stroke patients with upper limb motor deficits. Materials and methods: Fractional anisotropy (FA) values over the SLF I, SLF II, and corticospinal tract (CST) and upper limb motor performance evaluated by both the upper limb Fugl-Meyer Assessment score and maximum grip strength were measured for 16 patients at 3 weeks, 6 weeks, and 12 weeks poststroke. FA changes were assessed over time using repeated-measures Friedman ANOVA, and correlations between motor recovery, motor outcome at 12 weeks, and FA values in the CST, SLF I, and SLF II at 3 weeks were performed using Spearman's rank-order correlation. Results: FA values in the affected hemisphere's SLF I and SLF II at 3 weeks correlated with motor recovery at 12 weeks when assessed by the Fugl-Meyer Assessment for upper limb extremity (rho: 0.502, p: 0.04 and rho: 0.510, p: 0.04, respectively) but not when assessed by grip strength. FA values in the SLF I and SLF II were not correlated with motor outcomes. FA values in the SLF II in the affected hemisphere changed significantly over time (p: 0.016). Conclusion: Both SLF I and SLF II appeared to participate in poststroke motor recovery of complex movements but not in the motor outcome. These results argue that visually/spatially oriented motor tasks as well as more complex motor tasks using parietal associative areas should be used for poststroke rehabilitation strategies.

Evaluation of a shortened version of the Action Research Arm Test (ARAT) for upper extremity function after stroke: The Mini-ARAT.

OBJECTIVES: (i) to create a shortened version of the Action Research Arm Test scale, (ii) to investigate its psychometric properties compared to the original scale and (iii) to externally validate it within an independent cohort. DESIGN: Prospective longitudinal cohort study. SETTINGS: Two University Hospitals (France, Switzerland). PARTICIPANTS: 47 patients with poststroke motor deficits of the upper limb coming from two different sites were included and divided into two cohorts (n = 22 for the construction cohort; n = 25 for the validation cohort). MAIN MEASURES: We used the first cohort to build the Mini-ARAT by shortening the Action Research Arm Test scale on the basis of ceiling/floor effects and collinearity of the subscales. We studied its reliability, validity, and responsiveness and performed an external validation with the second cohort. RESULTS: The Mini-ARAT consisted of 2 subscales from the original Action Research Arm Test scale (Grip and Pinch). Internal consistency (α = 87) and inter-rater reliability (0.99, 95% CI: 0.98-0.99, p < 0.01) were good and similar to those of the Action Research Arm Test scale. The Minimal Clinically Important Difference of the Mini-ARAT was 9 points. The predictive validity in the construction and validation cohorts showed good correlation between the Mini-ARAT at baseline and the Fugl Meyer at 3 months (rho, 95% CI: 0.77, 0.49-0.90, p < 0.01, and 0.58, 0.19-0.96, p < 0.01). CONCLUSION: The Mini-ARAT is a time-effective tool able to capture the dynamics of motor deficits with high reliability and consistency, providing excellent information about residual motor functions, which is critically important for clinical and research purposes.