Characterizing Gait, Locomotor Status, and Disease Severity in Children and Adolescents with Friedreich Ataxia

Background and Purpose: The purpose of this study was to describe gait parameters in children and adolescents with a diagnosis of Friedreich ataxia (FA) and examine the relationship between disease severity, measured by the Friedreich Ataxia Rating Scale (FARS) and gait parameters. The study examined whether FARS scores can discriminate between those who walk independently and those who require assistance. Methods: Thirty-eight children (aged 5-11 years) and adolescents (aged 12-17 years) with genetically confirmed FA were divided into two groups based on locomotor status: group 1, subjects who were able to walk independently, and group 2, subjects who required assistance for walking. Temporal and spatial gait parameters were collected using the Stride Analyzer computerized foot switch system and compared with age-matched normative data. The FARS was used to measure disease severity. Correlation coefficients and the Mann-Whitney U test of differences were used to evaluate associations and discern differences between groups. Results: In subjects with FA, gait parameters of velocity and cadence were slower and stride length was shorter compared with age-matched children without disabilities. These parameters were significantly correlated with FARS score (r = 0.696, 0.667, 0.537; respectively, all P values < 0.001). Total FARS scores were correlated with locomotor status (c value r = 0.623; P < 0.01) and could categorize subjects into groups based on independent walking or need for assistance, 73% and 87% of the time, respectively. Discussion and Conclusion: Subjects with FA exhibited specific abnormal gait characteristics relative to age-matched individuals. Disease severity, as measured by the FARS, was associated with gait velocity, stride length, and cadence. FARS scores can be used to categorize subjects by locomotor status and may be a useful screening tool to identify those requiring assistance.