Closed-Loop Deep Brain Stimulation for Refractory Chronic Pain

Inclusion Criteria: 1. Age 22-80 years old 2. Clinical diagnosis of a refractory chronic pain syndrome including 1. post-traumatic pain syndromes (e.g. root avulsions, nerve crush injuries, spinal cord injury) 2. postsurgical pain syndromes (e.g., postmastectomy syndrome, post-thoracotomy syndrome, phantom limb pain, post-surgical spinal pain) 3. postherpetic neuralgia 4. complex regional pain syndrome 5. atypical facial pain 6. central pain syndromes (e.g. post-stroke pain, multiple sclerosis pain, post-radiation pain) 7. post-radiation plexopathy 3. Two or more years or more of medically refractory severe pain 4. Average daily pain for the past 30 days reported as \>6 on a 0-10 numeric rating scale (NRS) 5. Pain that fluctuates over a range of at least 3 points on the NRS 6. Patient has failed at least two pain medications from different classes as determined by a neurologist or pain management specialist with stable doses of medications for 30 days prior to baseline visit. 7. Lack of a surgically correctible etiology for the pain as determined by 2 independent surgeons 8. Ability to speak / read English 9. Capable of understanding and providing informed consent 10. Absence of significant cognitive impairment - score of 25 or greater on the Montreal Cognitive Assessment (MoCA) 11. Successful detection of pain biomarkers or positive symptomatic response to inpatient stimulation trial period if performed. Exclusion Criteria: 1. Major medical co-morbidities increasing the risk of surgery including uncontrolled hypertension, coagulopathy, severe diabetes, major organ system failure, active infection or history of implant related infections, immunocompromised state or malignancy with \< 5 years life expectancy 2. Presence of cardiac pacemakers/defibrillators, implanted medication pumps, intra-cardiac lines, any intracranial implants (e.g., aneurysm clip, shunt, cochlear implant, electrodes) or other implanted stimulators not compatible with RC+S system 3. Pregnancy or breast feeding: all women of child bearing potential will have a negative urine pregnancy test prior to undergoing their surgical procedure. 4. Active depression (BDI \> 20), Suicide attempt \</= 12 months or imminent suicide risk, or other untreated or uncontrolled psychiatric illness that evaluating psychiatrist would recommend exclusion of patient after neuropsychiatric evaluation. 5. History of substance abuse in past 3 years 6. Inability to stop anticoagulation or platelet anti-aggregation therapy for surgery and recovery. 7. Implantable hardware not compatible with MRI or with the study. 8. MR abnormalities that suggest an alternative diagnosis or contraindicate surgery 9. Previous cranial ablative surgery. 10. Previous deep brain stimulation surgery using an RC+S incompatible system 11. Major neurological disorder other than the one that led to the chronic pain including epilepsy or a neurodegenerative condition including inability to recharge the device. 12. Requires diathermy, electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS) 13. Allergies or known hypersensitivity to materials in the Summit RC+S system 14. Patients may be excluded from enrollment due to a condition that, in the judgment of the PI, significantly increases risk or reduces significantly the likelihood of benefit from DBS.