Inclusion Criteria:  Patients with a diagnosis of idiopathic Parkinson's disease at the stage of motor fluctuations despite optimal medical treatment L-DOPA sensitivity defined by motor improvement above 50% on the UPDRS-3 scale after a dose of 150% of the usual early morning treatment Indication for STN-DBS approved by the local multidisciplinary movement disorders committee. Patients between 18 and 70 years of age Patients covered by a health insurance scheme Signed informed consent.  Exclusion Criteria:  Significant cognitive decline defined as a score < 22 on the MoCA scale Mood disorders defined by a score > 20 on the Beck Depression Inventory Significant cortical atrophy or leukoencephalopathy visualised by brain MRI Contraindication to anaesthesia and MRI Lack of contraceptive treatment for women with ability to procreate Pregnant or breast-feeding woman Unstoppable anticoagulant or antiaggregant treatment Persons under legal protection (Persons deprived of liberty or incapable of giving consent or under curatorship or tutorship…) Patient with severe psychiatric disorders (on Diagnostic and Statistical Manual of Mental Disorders IV) Inability to follow the patient until the end of study