Closed-Loop Deep Brain Stimulation for Refractory Chronic Pain

Prior treatment

• Pregnancy or breast feeding: all women of child bearing potential will have a negative urine pregnancy test prior to undergoing their surgical procedure.
• MR abnormalities that suggest an alternative diagnosis or contraindicate surgery
• Previous cranial ablative surgery.
• Previous deep brain stimulation surgery using an RC+S incompatible system
• Requires diathermy, electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS)

Other illness

• 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
• 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.
• History of substance abuse in past 3 years
• 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.
• Allergies or known hypersensitivity to materials in the Summit RC+S system
• 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.

Lab values

• Inability to stop anticoagulation or platelet anti-aggregation therapy for surgery and recovery.

Age

• 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

Other

• Implantable hardware not compatible with MRI or with the study.

• Age 22-80 years old
• Clinical diagnosis of a refractory chronic pain syndrome including
  • post-traumatic pain syndromes (e.g. root avulsions, nerve crush injuries, spinal cord injury)
  • postsurgical pain syndromes (e.g., postmastectomy syndrome, post-thoracotomy syndrome, phantom limb pain, post-surgical spinal pain)
  • postherpetic neuralgia
  • complex regional pain syndrome
  • atypical facial pain
  • central pain syndromes (e.g. post-stroke pain, multiple sclerosis pain, post-radiation pain)
  • post-radiation plexopathy
• Two or more years or more of medically refractory severe pain
• Average daily pain for the past 30 days reported as \>6 on a 0-10 numeric rating scale (NRS)
• Pain that fluctuates over a range of at least 3 points on the NRS
• 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.
• Lack of a surgically correctible etiology for the pain as determined by 2 independent surgeons
• Ability to speak / read English
• Capable of understanding and providing informed consent
• Absence of significant cognitive impairment - score of 25 or greater on the Montreal Cognitive Assessment (MoCA)
• Successful detection of pain biomarkers or positive symptomatic response to inpatient stimulation trial period if performed.