Methods
SCA3, ataxia
SPINOCEREBELLAR ATAXIA TYPE 3, MAY
In May 2021, 20 individuals with spinocerebellar ataxia type 3 (SCA3) who participated in a randomized, double‐blind, sham‐controlled trial of cerebellar transcranial direct current stimulation (tDCS) received a custom‐designed questionnaire about short‐term and long‐term treatment expectations (ie, anticipated changes in ataxia severity after 2 weeks and 1 year of follow‐up, respectively), allocation preferences, and interpretation of treatment arm assignment based on the presence or absence of clinical improvement.Subjects were eligible for participation in the tDCS trial when they (1) had genetically confirmed SCA3, (2) were aged 16 years or older, and (3) were mildly to moderately affected, as defined by a SARA score between 3 and 20 at a prestudy visit. None of them had previously undergone tDCS. At the time of survey completion, disclosure of treatment assignment had not yet taken place, excluding bias due to knowledge of randomization status. Patients were informed as follows about the possible benefits of participation: “Despite the fact that a recent cerebellar tDCS trial showed a decrease in ataxia severity at the group level in 20 individuals with different types of ataxia that lasted 3 months, it is not known beforehand whether this also applies to SCA3 patients. It is therefore best to assume that there are no specific benefits of participation for yourself. However, if we are able to demonstrate in this study that tDCS reduces ataxia severity, this could have potential consequences for the future treatment of SCA3 patients.”Outcomes are generally reported using descriptive statistics. An unpaired The trial was approved by the local ethics committee (CMO region Arnhem‐Nijmegen). Written informed consent was obtained from all participants.