It is a chronic progressive degenerative disorder of the extrapyramidal system caused by loss of dopaminergic neurons in the substantia nigra and characterized by tremors, rigidity, bradykinesia, and disturbance of gait and posture. The neuropsychiatric symptoms of Parkinson's disease may include depression, psychosis, apathy, and impulse control disorders that are linked with the poor quality of life due to the progression of the disease. Despite this, cognitive impairment in PD is of great significance in terms of therapeutic approaches in order to deal with motor deficits of the disorder....