Longitudinal gait and balance decline in Friedreich's Ataxia: A pilot study.

INTRODUCTION: Friedreich's Ataxia (FA) is a devastating, progressive, neurodegenerative disease. Objective measures that detect changes in neurological function in FA patients are needed to facilitate therapeutic clinical trials. The purpose of this pilot study was to analyze longitudinal changes in gait and balance in subjects with FA using the GAITRite Walkway System® and Biodex Balance System™, respectively, and to test the ability of these measures to detect change over time compared to the Friedreich's Ataxia Rating Scale (FARS). METHODS: This was a 24-month longitudinal study comparing ambulatory FA subjects with age- and gender-matched, healthy controls. Eight FA subjects and 8 controls were tested at regular intervals using the GAITRite and Biodex Balance systems and the FARS. RESULTS: In the FA group, comfortable and fast gait velocity declined 8.0% and 13.9% after 12 months and 24.1% and 30.3% after 24 months, respectively. Postural stability indices increased in FA subjects an average of 41% from baseline to 24 months, representing a decline in balance. Subjects with FA also demonstrated a 17.7% increase in FARS neurological exam scores over 24 months. There were no changes in gait or balance variables in controls. In the FA group, multiple gait and balance measures correlated significantly with FARS neurological exam scores. CONCLUSIONS: The GAITRite and Biodex Balance systems provided objective and clinically relevant measures of functional decline in subjects with FA that correlated significantly with performance measures in the FARS. Gait velocity may be an important objective measure to identify disease progression in adults with FA.

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.