Utilization of ADL states as milestones indicating disease progression. Data from the 7-year IDR registry study was used to obtain information regarding the time that elapsed before patients became wheelchair dependent (A: Disease duration, B: Patient’s age). Among 37 patients with SCA6, 12 became wheelchair dependent during the 7 years of the study. The Kaplan-Meier curves are shown. The medians (95% confidence interval) of disease duration and age for those patients who became wheelchair dependent were 24.0 years (12.8 – 35.2 y) and 77.0 years (71.6 – 82.4 y), respectively. Abbreviations: ADL = activities of daily living; SARA = Scale for the Assessment and Rating of Ataxia; SCA6 = spinocerebellar ataxia type 6.