Inclusion Criteria:  Men and women (non-pregnant) aged between 21 and 80 years; Presence of deep brain stimulation in the subthalamic nucleus or globus pallidus Participants with idiopathic Parkinson's disease at Hoehn Yahr stages between 2 and 4 during off-medication, whose primary symptom includes altered gait and/or balance (score equal to or greater than 1 on sub-item 2.12 of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) ["gait and balance"]). Patients should present the above symptoms even though they are optimized from a drug point of view and with optimized programming. The criteria to be optimized will be defined by a neurologist specialized in movement disorders who will evaluate the case. Mini mental state exam greater than or equal to 24 points; Able to give informed consent in accordance with institutional policies; Able to meet all testing and follow-up requirements as defined by the study protocol  Exclusion Criteria:  Patients with unstabilized psychiatric comorbidities; Impossibility to consent to their participation in the study; Patients with uncontrolled infection or other uncontrolled pre-existing medical conditions (eg, decompensated diabetes, high blood pressure, symptomatic pneumo or heart disease); Concurrent treatment with other experimental drugs; Pregnant or breastfeeding women; Patients who cannot walk, not even with unilateral aid of a walking aid device or another person, when they are without their medication for Parkinson's Disease (off-medication); Presence of cardiac pacemaker.