Participants underwent anodal stimulation delivered by a battery-driven stimulator (Neuroelectrics, Barcellona, Spain) through a pair of saline-soaked surface sponge electrodes (7 x 5 cm2) producing a constant current of 2 mA for 20 min.

Anodal stimulation was delivered by a battery-driven stimulator (Neuroelectrics, Barcellona, Spain) through a pair of saline-soaked surface sponge electrodes (7 x 5 cm2) producing a constant current of 2 mA for 20 min. The anode was placed 2 cm under the inion and the cathode was placed over the right deltoid muscle (CD-tDCS) or the spinal lumbar enlargement (2 cm under T11) as described by Benussi et al. (CS-tDCS). An electroconductive gel was applied to the electrodes to reduce contact impedance and the electrodes were held in place using elastic gauzes.

Modified International Cooperative Ataxia Rating Scale (MICARS) was used to rate ataxic symptoms. Scores range from 0 (no impairment) to 100 (maximum impairment) Higher scores indicate worse impairments

A clinical-perceptual method exploring all components potentially involved in speech difficulties. Minimum score is 0 (higher impairment) maximum score is 284 (no impairments) Higher scores indicate better speech abilties

Instrumental assessment of gait speed (m/s) using motion capture system. Higher speed indicate improvements

Instrumental assessment of step width (m) using motion capture system. Smaller values of step width indicate gait improvements