Functional MRI and DTI in the Preoperative Assessment of Dystonia

Inclusion Criteria: * Age limits ≥ 18 et \< 85 years * Right-handed patients/healthy controls, according to Edinburgh Handedness Inventory * The participating subjects must be affiliated to the French public health system * Written consent to participate in this study For the patients * Patients affected by isolated or complex dystonia admitted to hospital in the Unit of Functional Neurosurgery in order to assess eligibility for deep cerebral stimulation therapy * Ability to understand the instructions to perform the experimental paradigm (the motor task) used in the design of the functional MRI For the healthy control subjects : * Absence of current neurologic pathology * Absence of personal history of neurologic pathology, including perinatal anoxic injury, meningitis, vascular, metabolic, inflammatory pathology, epilepsy, cranial trauma with loss of consciousness or with associated neurological symptoms. * Absence of orthopaedic injury in the upper limbs Exclusion Criteria: * Non Specific criteria * Contraindication for the realization of a MRI (pacemaker, valve prothesis non compatible with MRI, cochlear implant, aneuvrysmal clip, presence of an Intra-ocular metallic foreign object or coronary endoprosthesis) * Pregnancy, breastfeeding * Adults protected by the law * Non Specific criteria • Severe dyskinesia preventing the realization of motor task during functional MRI without general anesthesia