Profile of lower limb muscle strength, postural control and gait speed in individuals with spinocerebellar ataxia

Abstract

Introduction: Spinocerebellar ataxia (SCA) is a family of dominant hereditary cerebellar ataxias that progressively degenerate the cerebellum and its pathways, causing postural instability and incoordination. Objective: The objective is to analyze the performance of these individuals in tests related to gait and postural control and compare them to health. Methods: 39 individuals with SCA were invited to participate. Of these, 4 did not agree to participate (N=35). 30 healthy participants, matched in gender and age, were recruited. A sample of patients was detailed through the application Scale of the Assessment and Rating of Ataxia (SARA) and the Inventory of Non-Ataxia Signs (INAS). All participants were evaluated using the following instruments: Five times sit to stand (5TSTS), 10m walk test (10MWT) and Functional reach test (FRT) with accelerometry. During FRT, a linear artifact was acquired using signals from 3D accelerometers integrated into an Apple smartphone (Iphone 13, designed by Apple in California USA, assembled in Brazil) positioned in the lumbar region. The patients were subdivided into three groups, according to the scores obtained on the SARA scale relating to the level of dependence when performing ADL (minimum-moderate, maximum and severe-total dependence). To compare the control group and patient subgroups, a one-way ANOVA was performed, followed by posttests in case of a significant main effect. Analysis of accelerometer recording during FRT was performed by comparing data from sensitive patients with patients using a ttest for independent samples. Results: For the analyzes of the 5TSTS, FRT and 10MWT, data from 35 patients with SCA were used as well as 30 height controls. For the analysis of the movement pattern during FRT with accelerometry, data were included from 28 patients with SCA and 22 controls were included with high-quality signals found to be sufficient to be analyzed. There was a main effect when comparing groups for all variables: 5TSTS (P<0.001); TAF (P<0.001); Time in the 10MWT (P<0.001); number of steps in the 10MWT (P<0.001). The distances achieved in the FRT by the control group were significantly higher than those of the maximum and severe-total dependence groups, while for the minimal-moderate dependence group, there were no significant differences compared to the control group. Regarding the TAF movement phases, there were no significant differences for any variable (P<0.132). Conclusion: The results indicate that SCA impacts patients' gait and postural control. In general, individuals with SCA with greater dependence for ADL and worse disease severity had the worst performance in the tests. Although the distances
reached in the FRT were smaller for patients with SCA, the movement phases did not show significant differences between them, showing that the movement pattern is not significantly altered. These results help to improve the treatment of patients, highlighting the changes that can cause disease progression, identifying the areas in which patients have more difficulties, and pointing to the use of specific instructions based on the results of specific assessments.