Effect of ctDCS During Balance Training on Cerebellar Ataxia

Effects of Cerebellar Transcranial Direct Current Stimulation During Balance Training on Cerebellar Ataxia

Cerebellar ataxia is a neurologic symptom caused by damage or dysfunction in the cerebellum and its pathways that results in loss of coordination, balance and postural control. There is a high rate (93%) of fallings for this population that could limit daily life activities. Pharmacological interventions are not able to modify the balance, therefore, new approaches to rehabilitate must be studied. ctDCS is a non-invasive brain stimulation that seems to be a new and innovator technique to restore ataxia symptoms. The purpose of this study is to evaluate the effects of ctDCS associated with balance training on cerebellar ataxia patients. A counterbalanced crossover, sham-controlled, triple blind trial will be performed. All subjects will receive the real and sham ctDCS associated to balance training. The anodal ctDCS (2 mA, 20 minutes) or sham (2mA, 30 seconds) will be applied during balance training at Biodex Balance System (BBS). The balance will be the primary outcome and will be evaluated through Posture Control at Biodex Balance System. Ataxia' severity and functional mobility will be the secondary outcomes and will be evaluated by the scale for the assessment and rating of ataxia (SARA) and 10 meters walking test, respectively.

Non-invasive brain stimulation technique is able to modulate the brain activity through a low-intensity current. The anodal will be positioned 1 cm below inion and cathodal in the right deltoid muscle. 20 minutes with a 2mA current.

Non-invasive brain stimulation technique is able to modulate the brain activity through a low-intensity current. The anodal will be positioned 1 cm below inion and cathodal in the right deltoid muscle. 30 seconds with a 2mA current.

The change in balance will be assessed through postural control index of Biodex Balance System. This postural control index is a continuous variable where lower index means less instability and better balance.

The ataxia' severity will be assessed by the Scale for the Assessment and Rating of Ataxia (SARA). It consists of eight items (gait, stance, sitting, speech disturbance, finger chase, nose-finger test, fast alternating, hand movements, and heel-shin slide), where higher score (40) mean more severe ataxia, whereas lower score (0) means less ataxia symptoms. The score happens about the sum of the eight items.

The patient will walk 10 meters and the time will be measured to determine the functional mobility. Where lower time to walk 10 meters, better functional mobility.

Inclusion Criteria: Cerebellar ataxia Score > 1 ≤ 4 on posture of Scale for assessment and rating of ataxia Exclusion Criteria: Individuals with other neurological disorders, postural hypotension, vestibular, visual, cardiovascular or musculoskeletal disorders that affect the performance of the proposed tests; Pacemaker; History of seizures; Metallic implants in the head or neck; Medication change (3 months) during the period of study