The present invention provides compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein R1 and R2 are as defined in the specification, for use in the prevention or treatment of an ataxic disorder.本發明提供式(I)化合物及其醫藥學上可接受之鹽,其中R1與R2係如說明書中所定義,其係用於預防或治療共濟失調症。