Inclusion Criteria:  Japanese patients Patients who are diagnosed with Parkinson's disease according to UK Parkinson's Disease society brain bank clinical diagnostic criteria Patients with Parkinson's disease in Stages 1 to 3 on the Modified Hoehn and Yahr Scale  Exclusion Criteria:  Patients who are suspected any parkinsonism except for idiopathic Parkinson's disease. Patients who underwent neurosurgical treatment (stereotaxic destruction, deep brain stimulation etc.) for PD, or patients for whom surgical treatment is scheduled during the study Patients with a complication of obvious dementia, or patients with Mini-Mental State Examination (MMSE) score < 24 points