tDCS Associated With Locomotor Training on Functional Mobility of Cerebellar Ataxia

Effects of Cerebellar Transcranial Current Stimulation Associated With Locomotor Training on Functional Mobility of Subjects With Cerebellar Ataxia

Cerebellar ataxia is a neurologic symptom caused by a damage or a dysfunction in cerebellum and results in loss of coordination, balance and postural control. This impairment could result in a reduction of walking speed, short and irregular steps and difficulty in coordinating between lower limbs. Pharmacological interventions are not able to modify ataxia gait pattern, therefore, new approaches to rehabilitate must be studied. Treadmill locomotor training (TLT) and cerebellar transcranial direct current stimulation (ctDCS) are physical therapy techniques able to module cerebellar afferences and modify positively ataxia gait pattern. However, there is no study involving the association of these two techniques. The purpose of this study is to evaluate the effects of ctDCS associated to TLT on functional mobility in subjects with cerebellar ataxia. A randomized, sham controlled, double blind clinical trial will be performed. The subjects will be randomly allocated into two groups: (i) ctDCS associated with TLT; (ii) ctDCS sham associated with TLT. The TLT will be performed with a speed and step length progression protocol for 25 minutes. The anodal ctDCS (2 mA, 25 minutes) or sham (2mA, 30 seconds) will be applied during TLT. The functional mobility will be the primary outcome and will be evaluated through timed up and go test (TUG). Ataxia' severity, balance and fall risky, will be the secondary outcomes and will be evaluated by the scale for the assessment and rating of ataxia (SARA), balance evaluation system test (miniBest) and TUG, respectively.

Cerebellar transcranial direct current stimulation (ctDCS) will be applied during 25 minutes at 2 mA of intensity. Anodal electrode will be positioned 1 cm below inion and cathodal electrode at right deltoid muscle.

The Treadmill Locomotor Training (TLT) will be performed through speed and step length progression protocol for 25 minutes and combined to ctDCS

Sham Cerebellar transcranial direct current stimulation (ctDCS sham) will be applied during 30 seconds at 2 mA of intensity. Anodal electrode will be positioned 1 cm below inion and cathodal electrode at right deltoid muscle. However, subjects will keep the placement of electrodes for 25 minutes to ensure stimulation's masking.

The evaluation of the functional mobility of individuals will be performed by the Timed Up and Go test. It will analyze the time spent by the individual to get up from a chair with arms, walk for three meters and return to the chair. Longer times to performe the Timed Up and Go test mean worse functional mobility.

The evaluation of the functional mobility of individuals will be performed by the Timed Up and Go test. It will analyze the time spent by the individual to get up from a chair with arms, walk for three meters and return to the chair. Longer time values and step numbers represent a greater risk of falls. Time greater than 10 seconds in the test means greater risk of falling.

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 ranges from 0 to 40. Higher score mean more severe ataxia.

The balance of individuals will be assessed through the Balance Evaluation System Test (BESt), which comprises 14 items with a score of 0-2 each from 0 (worst) to 2 (best performance), used to assess dysfunction in balance and independence in life activities daily.

The patient's global impression is a questionnaire which the patient has to answer how the treatment changed his life daily activities. Patient will choose the best option that reflects their improvement in quality of life, from "no change" to "much better with differences that have made all the difference".

Brunoni's questionnaire will be used to ask the patient about some possible adverse effects related to stimulations. The patient will be asked always at the end of each stimulation (real or sham).

Inclusion Criteria: Cerebellar ataxia Ages: 18 to 65 years; Gender: Both; Score ≥ 3 and < 8 in subscore of gait in the Scale for the 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 during the period of study