Table 2.
Outcome measures and tests
| Outcome domain | Test | Time point |
|---|---|---|
| Primary outcome measure | ||
| Cerebellar ataxia severity | SARA (absolute change from baseline) | T1 |
| Secondary outcome measures | ||
| Cerebellar ataxia severity | SARA (% of patients with a decrease of ≥ 1.5 points) | T1 |
| Cerebellar ataxia severity | SARA score and subscores | T0 after tDCS, T2-T4 |
| Gait speed | 8 m walk test | T0 after tDCS, T1-T4 |
| Articulation speed | PATA repetition rate | T0 after tDCS, T1-T4 |
| Upper limb dexterity | 9-hole peg test | T0 after tDCS, T1-T4 |
| Extracerebellar signs | INAS count | T1-T4 |
| Postural sway | Static posturography | T0 after tDCS and T1 |
| Quality of life | EQ-5D-5L | T1-T4 |
| Depression | PHQ-9 | T1-T4 |
| Mood states | POMS 32-item version | T1-T4 |
| Cognition and affect | CCAS scale (total score and number of ‘fails’) | T1-T4 |
| Activities of daily living | FARS part II | T1-T4 |
| Medical consumption | iMCQ | T4 |
| Motor learning | Delay EBC (acquisition of CRs) | T1 |
| CBI | Transcranial magnetic stimulation | T1 |
| tDCS-related side effects | Open question | T1 |
| Correct randomization | Patients’ thoughts about treatment allocation | T1 |
SARA Scale for the Assessment and Rating of Ataxia, INAS Inventory of Non-Ataxia Signs, EQ-5D-5L EuroQol 5-Dimension 5-Level, PHQ-9 Patient Health Questionnaire-9, POMS Profile of Mood States, CCAS Cerebellar Cognitive Affective Syndrome, FARS Friedreich Ataxia Rating Scale, iMCQ Institute for Medical Technology Assessment (iMTA) Medical Consumption Questionnaire, EBC Eyeblink conditioning; CR Conditioned response, CBI Cerebellar brain inhibition