The Effects of Tele-Rehabilitation-Based Dual-Task Upper Extremity Training in Patients With Parkinson's Disease

The aim of this study is to compare the effects of tele-rehabilitation-based synchronous and asynchronous dual-task upper extremity training with clinical based dual-task upper extremity training and conventional single-task upper extremity training in patients with Parkinson's disease. The main questions it aims to answer are: * Whether there are differences in motor symptoms, hand dexterity, upper extremity functions, grip strength, executive functions, daily living activities, and treatment satisfaction between tele-rehabilitation-based synchronous and asynchronous dual-task upper extremity training, clinical-based dual-task upper extremity training, and conventional single-task upper extremity training in patients with Parkinson's disease. * Whether there is a difference in telemedicine satisfaction between tele-rehabilitation-based synchronous and asynchronous dual-task upper extremity training in patients with Parkinson's disease. Researchers will compare conventional single-task upper extremity training, clinical-based dual-task upper extremity training, tele-rehabilitation-based synchronous upper extremity training and tele-rehabilitation-based asynchronous upper extremity training. Participants will: * Receive upper extremity exercise training at the study clinic or home, twice a week for approximately 60 minutes each time, for 6 weeks. * Participate in assessments at the study clinic before and after exercise training.