REM behavior disorder and excessive daytime somnolence in Machado-Joseph disease (SCA-3).

We reported previously that behavior suggestive of rapid eye movement sleep behavior disorder (RBD) was markedly increased in a small population of SCA-3 patients. We, therefore, asked patients and nonpatient attendees at an SCA-3 annual clinic to complete a questionnaire soliciting RBD-like behavior. Our results support the previous observation that RBD-like behaviors are significantly increased in SCA-3.