Objective: To quantify longitudinal changes in gait in Friedreich’s Ataxia (FA) patients compared to controls during a 24-month period using the GAITRite Walkway System.
Background: FA is a devastating neurodegenerative disease. Measures to accurately quantify small changes in neurological function in FA patients are needed to facilitate therapeutic clinical trials.
Design/Methods: This was a prospective, longitudinal study that assessed ambulatory FA patients compared to age- and gender-matched controls. FA patients were examined at baseline and at 6, 12, and 24 months, using the GAITRite Walkway system, a portable instrument used to assess gait parameters, and the Friedreich’s Ataxia Rating Scale (FARS). Controls were evaluated at baseline and 12 months. Changes in various gait parameters over time were estimated and compared using descriptive statistics and multilevel modeling.
Results: Eight FA patients (aged 29.4 ± 9.0) and 8 controls (aged 29.6 ± 9.1) were included in this analysis. In FA patients, the mean FARS score increased 21.0[percnt] over two years (baseline: 40.6; 12 months: 45.4; 24 months: 49.1). Using longitudinal multilevel modeling, the FARS score was estimated to increase 0.13 points per month in FA patients, reflecting an increase in neurological dysfunction. Comfortable gait velocity declined 15[percnt] after 12 months and 30.5[percnt] after 24 months in the FA group, and showed high validity for measuring neurological dysfunction. Comfortable gait velocity correlated strongly with the FARS total score (r=-0.536;p <0.002), FARS lower extremity coordination (r=-0.424;p = 0.015) and FARS upright stability score (r=-0.191;p =0.002), and had high reproducibility (r=0.90).
Conclusions: Comfortable gait velocity as measured by the GAITRite system showed better sensitivity to changing gait that did the FARS, and had excellent reproducibility in controls whose gait was not expected to change. Comfortable gait velocity is easily performed, and may be an important and clinically relevant endpoint for future clinical trials.
Available at: http://works.bepress.com/kelly_sullivan/179/