Neurostimulation for Treatment of Chronic Upper Limb Pain After Brachial Plexus Injury

Inclusion Criteria: * Age \> 18 years old * Neuropathic pain of the upper limb ≥ 3 months following brachial plexus avulsion injury. * Patients must be planned to undergo implantation of high-frequency spinal cord stimulation for the treatment of chronic neuropathic pain due to brachial plexus avulsion injury. Exclusion Criteria: * Pain that is non-neuropathic as defined by DN4 score \<4. * Pregnant at the time of consideration for implant or planning to become pregnant during the study duration. * Active substance use disorder of any kind. * Active tobacco use. * Use of moderate or high dose opioid medication (oral morphine equivalents \>100 mg daily). * Active, untreated major psychiatric disorder that might interfere with subject's ability to participate. * Involvement in active litigation related to injury. * Patient has not undergone conservative medical management for at least 3 months (including physical and/or occupational therapy and at least one trial of neuropathic pain medication).