Transcranial Direct Current Stimulation and Balance

Postural control is an adaptive sensorimotor process involving continuous integration of sensory information from three channels. These; visual, somatosensory (proprioceptive) and vestibular senses. The study will be carried out at Istanbul Medipol University. 30 healthy individuals between the ages of 18-25 will be included. To each individual Anodal-supplementary motor area tDCS, Anodal-cerebellar tDCS, Sham tDCS applications will be cross-applied. tDCS application will take 20 minutes and each individual will receive 3 sessions in total. There will be a 72-hour rest period between sessions. Individuals assessed with Demographic Information Form for demographic information, Wii-Fit and Balance Error Scoring System for Static Balance Evaluation, Star Balance Test and Timed Get Up and Go Test for Dynamic Balance Assessment. The aim of this study is to investigate the effect of transcranial direct current stimulation applied on the supplementary motor area and cerebellum on static and dynamic balance in healthy individuals.

Postural control is an adaptive sensorimotor process involving continuous integration of sensory information from three channels. These; visual, somatosensory (proprioceptive) and vestibular senses. The cerebellum plays an important role in the planning, initiation and stability of movements, as well as in postural control and balance. The Supplementary Motor Area (SMA) is a section of the cortex that plays a major role in planning both simple and complex motor movements; It has many functions such as sequence of movements (turning one's hand before picking up an object), learning (learning a new balance task), acquiring grammar. The SMA is somatotopic organized and has direct reciprocal connections with the primary motor cortex (M1). Independent of the primary motor cortex (M1), the SMA is thought to play a crucial role in planning motor actions before movement begins. It also contributes to the planning of all body movements together with the basal ganglia and cerebellum during challenging balance tasks.

Modulation of neural regions underlying balance control may be a potential alternative for therapy. Transcranial direct current stimulation (tDCS) is a non-invasive and safe tool that can modulate cerebellar activity. tDCS is an easy, inexpensive and portable device to implement. There are 3 different types of stimulation. While anodal stimulation promotes neural excitability by causing subthreshold depolarization, cathodal stimulation inhibits neural activity, and in addition, anode-cathode application, in which two types of stimulation are used together, provides both facilitation and inhibition according to electrode placement. In a study conducted by Foerster et al. in healthy individuals in 2017, it was found that cerebellar tDCS increased balance stability, and in a study by Ehsani et al. in healthy individuals over 60 years of age in 2017, cerebellar tDCS increased the Berg Balance balance score. In a study conducted by Steiner et al. in 2016 in which cerebellar tDCS was applied to young individuals, it was observed that the trunk deviation angle during balance was decreased in men, while a similar study by Inukai et al. showed a decrease in oscillation after cathodal cerebellar tDCS.

There are studies showing that tDCS applied to the supplementary motor area has positive contributions to balance. It has been shown by Nomura et al. that tDCS applied to the supplementary motor area in healthy individuals causes a significant increase in balance.

There is no study comparing supplementary motor area and cerebellar area application in healthy individuals where tDCS is applied.

In line with these studies, the aim of this study is:

To investigate the effect of transcranial direct current stimulation applied on the supplementary motor area and cerebellum on static and dynamic balance in healthy individuals.

The study will be carried out at Istanbul Medipol University. 30 healthy individuals between the ages of 18-25 will be included.

To each individual:

1. Anodal-supplementary motor area tDCS
2. Anodal-cerebellar tDCS
3. Sham tDCS applications will be cross-applied. tDCS application will take 20 minutes and each individual will receive 3 sessions in total. There will be a 72-hour rest period between sessions. Evaluations will be made at the beginning and will be repeated immediately after tDCS applications.

Inclusion Criteria:

* No neurological, sensory, motor, visual or cognitive impairment,
* Volunteering to participate in the study,
* Being between the ages of 18-25,
* To have formal education at the university.

Exclusion Criteria:

• Being diagnosed with a psychological disorder.

Evaluations will be made in the presence of a physiotherapist. Individuals; For demographic information

• Demographic Information Form

For Static Balance Evaluation:

* Wii-Fit
* Balance Error Scoring System

For Dynamic Balance Assessment:

* Star Balance Test
* Timed Get Up and Go Test

It will be evaluated with IBM SPSS "Statistical Package for Social Sciences".

Eligibility Criteria:
Inclusion Criteria:

* No neurological, sensory, motor, visual or cognitive impairment,
* Volunteering to participate in the study,
* Being between the ages of 18-25,
* To have formal education at the university.

Exclusion Criteria:

* Being diagnosed with a psychological disorder.