Parkinson's Disease (PD) is the second most common neurodegenerative disorder. The period that apparent cognitive deficits exist without disrupting daily life activities is named as Mild Cognitive Impairment (PD-MCI). Treatments were considered to be more efficacious in PD-MCI than PD dementia as relatively less permanent changes in cortical structures occured. No approved treatments exist in PD-MCI and non-pharmacological treatments are under investigation as drugs have considerable amount of adverse effects.~Event Related Potentials (ERP) measurements have the advantages of providing direct and objective evidence of central nervous system functions, imaging of the activity of the cortical areas and being unaffected by motor deficits. ERP parameters were found to be related to cognitive functions and disrupted in PD and PD-MCI. Thus, ERP parameters were suggested to be useful in treatment efficacy assessment.~Transcranial Direct Current Stimulation (tDCS) is a promising non-invasive brain stimulation method. Ameliorating effects of tDCS on cognition and ERPs were observed. Enhancing effects of tDCS on some cognitive deficits were also reported in PD.~Few studies reported the efficacy of both tDCS and physical therapy/cognitive training and none assessed the efficacy of tDCS solely, compared to a sham control group. All studies assessed the efficacy without using electrophysiological measurements that reflect central nervous system functions directly. In this project, the efficacy of tDCS will be compared to a sham tDCS group and be assessed with electrophysiological measurements for the first time.~The study is a double-blind randomized controlled trial. The sample will be consisted of twenty six participants diagnosed as having PD-MCI due to Movement Disorders Society Level 2 criteria. The participants will be assigned to active or sham groups. Then, neuropsychological test performances and ERP parameters during Oddball paradigm and Continuous Performance Test will be measured. Then, participants will be applied ten active or sham sessions of left anodal/right cathodal tDCS over the dorsolateral prefrontal cortex (DLPFC). All measurements will be repeated both immediately and 1-month after the applications.~Succinctly, the aim of this project is to assess the effect of ten sessions left anodal/right cathodal tDCS over the DLPFC on cognitive functions and electrophysiological parameters in PD-MCI.
The aim of the present study is to investigate the efficacy of prefrontal transcranial Direct Current Stimulation (tDCS) on cognitive functions and electrophysiological measures in Parkinson's Disease Mild Cognitive Impairment (PD-MCI). The participants will be assigned to active and sham groups (1:1) and will receive 10 sessions of tDCS (twice a day) for 5 days. The study will also examine if the effects may last for a month. The participants will be assigned to active and sham groups (1:1) and will receive 10 sessions of tDCS (twice a day) for 5 days. The study will also examine if the effects may last for a month.