Dual Task Training in Parkinson's Disease

Postural Stability will be evaluated with Biodex Biosway Portable Balance System (Biodex Medical Systems Inc., Shirley, New York).. Postural Stability test will performed on both feet and on the left and right foot separately. Total stability index score will obtained as the test result.

Limits of Stability will be evaluated with Biodex Biosway Portable Balance System (Biodex Medical Systems Inc., Shirley, New York). Limits of Stability test assesses how much the center of gravity is displaced on the support surface without losing balance during the standing position. Total direction control score will obtained as the test result.

Modified Sensory Organization Tests will be evaluated Biodex Biosway Portable Balance System (Biodex Medical Systems Inc., Shirley, New York). MSOT assesses the effects of somatosensory, visual and vestibular senses on postural control during the standing position. It evaluates the sensory component of balance in two different visual conditions and on two different support surfaces; condition 1: eyes open-firm surface, condition 2: eyes closed-firm surface, condition 3: eyes open-foam surface and condition 4: eyes closed-foam surface. Stability index scores will obtained as the test result.

Gait speed will be evaluated by using the BTS-G Walk system and recorded as m/min. It is a wireless system positioned on L5 vertebrae of the spine. It allows a functional objective gait analysis to be performed.

Cadence will be evaluated by using the BTS-G Walk system and recorded as strides/min. It is a wireless system positioned on L5 vertebrae of the spine. It allows a functional objective gait analysis to be performed.

Stride width will be evaluated by using the BTS-G Walk system and recorded as meters. It is a wireless system positioned on L5 vertebrae of the spine. It allows a functional objective gait analysis to be performed.

Stride length will be evaluated by using the BTS-G Walk system and recorded as meters. It is a wireless system positioned on L5 vertebrae of the spine. It allows a functional objective gait analysis to be performed.

Montreal Cognitive Assessment (MoCA) will be used in order to evaluate cognition. It assesses different cognitive domains: attention and concentration, executive functions, memory, language, visuoconstructional skills, conceptual thinking, calculations, and orientation.It' score ranged from 0 to 30 and higher points indicates better cognitive outcomes.

Brain derived neurotrophic factor (BDNF) levels of serum will be measured by using sandwich enzyme-linked immunosorbent assay (ELISA) kit.

Vascular endothelial growth factor (VEGF) levels of serum will be measured by using sandwich enzyme-linked immunosorbent assay (ELISA) kit.

Insulin like growth factor 1 (IGF-1) levels of serum will be measured by using sandwich enzyme-linked immunosorbent assay (ELISA) kit.

Hoehn and Yahr Scale is measures level of physical disability in Parkinson's disease and stages patients between level 1 level 5. Higher level indicates worse physical condition.

The Unified Parkinson's Disease Rating Scale (UPDRS) is a widely used measure of impairment and disability associated with Parkinson's Disease (PD) consisting of four sections: (1) Mentation, behavior, and mood; (2) Activities of daily living (ADLs); (3) Motor; and (4) Complications.Sections I through III are scored using a 5-point Likert-type scale (0 = no impairment; 4 = marked impairment). Although individual sections are scored and reported independently, scores from sections I through III are also summed to provide a UPDRS Total score. The UPDRS total score ranges between 0 and 199 points. Higher points indicates worse outcome.

Berg Balance Scale (BBS) is a scale that using for assess postural stability. It ranges 0-56 with higher score indicates better stability.

The duration participant is able to maintain their balance on one leg up to will be recorded.

Time in seconds a person needs to stand up from a chair, walk a distance of 3 meters, turn around a flag, come back and sit down again.

Activities-specific Balance Confidence scale (ABC), to quantify the level of confidence in performing a specific task without losing balance or becoming unsteady.

Stroop test will be used to test cognitive function.

The Trail Making Test is a measure of attention, speed and mental flexibility.

The short-form 8-item Parkinson's disease Questionnaire (PDQ-8) is the most commonly used scale measuring health related quality of life (HRQoL) in PD patients. It includes 8 items, and each item has five options (never, occasionally, sometimes, often, always or cannot do at all). The total score ranges from 0 to 32. Higher scores indicates poorer quality of life.