EEG Mapping During High Frequency/High Density Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome

Inclusion Criteria: 1. Subject is at least 18 years old. 2. Subject is able and willing to comply with the follow-up schedule and protocol 3. Diagnosis of FBSS with predominant leg pain (VAS) \> 5) and non-dominant back pain. 4. Cognitive and language functioning enabling coherent communication between the examiner and the subject; 5. Failed conservative treatments for pain including but not limited to pharmacological therapy and physical therapy 6. Stable neurologic function in the past 30 days 7. In the opinion of the Investigator, the subject is psychologically appropriate for the implantation for an active implantable medical device 8. Subject is able to provide written informed consent 9. Subject speaks Dutch or French. Exclusion Criteria: 1. Female subject of childbearing potential is pregnant/nursing, or plans to become pregnant during the course of the trial 2. Subject has had radiofrequency treatment of an intended target DRG within the past 3 months 3. Subject currently has an active implantable device including ICD, pacemaker, spinal cord stimulator, deep brain stimulator or intrathecal drug pump 4. Subject is unable to operate the device or has no relative available. 5. Subjects with indwelling devices that may pose an increased risk of infection 6. Subjects currently has an active infection 7. Subject has, in the opinion of the Investigator, a medical comorbidity that contraindicates placement of an active medical device 8. Subject has participated in another clinical investigation within 30 days 9. Subject has a coagulation disorder or uses anticoagulants that, in the opinion of the investigator, precludes participation 10. Subject has been diagnosed with cancer in the past 2 years 11. Life expectancy \< 6 months 12. Imaging (MRI, CT, x-ray) findings within the last 12 months that, in the Investigator's opinion, contraindicates lead placement 13. Existing extreme fear for entering MRI 14. General contraindication for MRI (pacemaker, etc…) 15. Age male/female patient \<18 years