This study evaluates the hypothesis that the gas mixture with xenon will have a positive effect on the symptoms in patients with Parkinson's Disease. The study will test the hypothesis that the gas mixture with xenon has a symptomatic treatment potential for patients with Parkinson's Disease, as measured by change from baseline in the Unified Parkinson Disease Rating Scale (UPDRS).

Inclusion Criteria:

• The patient must be male or female over the age of 18.
• The subject must have idiopathic Parkinson's disease.
• The subject has Stage III by Hoehn and Yahr in the "on" state on a screening visit
• Subjects suffering from anxiety, depression, cognitive dysfunction
• Dopaminergic drugs should be taken in a stable dosage for 28 days prior to registration, and throughout the study
• Patients who have signed an approved consent form and are consistent with both the clinical trial plan and follow-up.

Exclusion Criteria:

• Patients have atypical parkinsonism (eg, neuroleptics, metoclopramide, flunarizin), metabolic neurodegenerative disorders (eg, Wilson's disease), encephalitis, cerebrovascular disease or degenerative disease (e.g. progressive supranuclear palsy)
• Patients who received deep brain stimulation
• Patients with cancer, HIV, kidney or liver disease.
• Patients taking new antipsychotic, antidepressant, anxiolytic or narcotic drugs for less than 3 months