Cerebellar Transcranial Direct Current Stimulation in Spinocerebellar Ataxia 38

Comparison of Two Therapeutic Approaches of Cerebellar Transcranial Direct Current Stimulation in a Sardinian Family Affected by Spinocerebellar Ataxia 38: a Clinical and Computerized 3D Gait Analysis Study.

Spinocerebellar ataxia 38 (SCA 38) is a very rare autosomal dominant inherited disorder caused by a mutation in ELOV5 gene, specifically expressed in cerebellar Purkinje cells, encoding an enzyme involved in the synthesis of fatty acids. The present study aimed to assess the effect of cerebellar anodal transcranial direct current stimulation (tDCS) administered employing deltoid (CD-tDCS) and spinal (CS-tDCS) cathodal montage. Clinical evaluation was performed at baseline (T0), after 15 sessions of tDCS (T1) and after one month of follow-up (T2).

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

Instrumental assessment of double support phase duration (s) using motion capture system. Smaller values of double support phase duration indicate a more stable gait

Inclusion Criteria: age ≤ 80 and > 18 years diagnosis of SCA 38 with the presence of clinical symptoms. Exclusion Criteria: Inability to understand and sign the informed consent Presence of other severe neurological disorders presence of significant medical or psychiatric illnesses Pregnancy.