Inclusion Criteria:  Clinical diagnosis of Parkinson's disease Subthalamic Nucleus Deep Brain Stimulation with chronic conventional stimulation at 60 usec and 130 Hz for at least 3 months Movement Disorder Society UPDRS part III 3.11 >1 Freezing of Gait Questionnaire item-3 >1 Movement Disorder Society UPDRS part III 3.1 >1 Montreal Cognitive Assessment > 26 No psychiatric disorders All patients will be ≥ 18 years of age Documented informed consent  Exclusion Criteria:  no documented informed consent axial disorders not related to Parkinson's disease