From Nerve to Brain: Toward a Mechanistic Understanding of Spinal Cord Stimulation in Human Subjects

Eligibility Criteria

• * Aged 18 to 80
• * Capable of providing informed consent and following trial procedures, including capacity to complete self-reported measures of pain, function, and other outcomes
• * Stably implanted spinal cord or dorsal root ganglion stimulator
• * Device is to treat back/radicular lower extremity pain or neck/arm pain
• * Device with a paresthesia-free setting
• * Patients who are not on a stable dose of opioids or are on a stable dose greater than 100 MME/day per day within the two months prior to enrollment, or those who are unwilling to maintain a stable dose of opioids throughout the duration of the study
• * The investigator concludes that the participant is unable to differentiate back or neck/arm pain from other pains
• * Systemic or psychiatric illness that in the opinion of the site investigator would interfere with the individual's ability to participate in the trial
• * Other factor that in the opinion of the site investigator would interfere with the individual's ability to participate in the trial or tolerate the study procedures
• * Stimulation device is not 3 Tesla magnetic resonance imaging compliant
• * Contraindications to magnetic resonance imaging and/or positron emission tomography scanning (including presence of a cardiac pacemaker or pacemaker wires, vascular clips in the head or previous neurosurgery, prosthetic heart valves, claustrophobia)
• * Pregnant or breastfeeding
• * Participants with a low affinity binder phenotype based off testing for the Ala147Thr polymorphism.
• * Current or recent use of benzodiazepines (except for alprazolam, clonazepam, and lorazepam). Recent use will be defined based off the benzodiazepines half-life, such that patients who stopped taking the medication at least five half-lives ago will be considered eligible for scanning.
• * Subjects who have exceeded (or would exceed if they were to participate) the yearly amount of allowable radiation, as defined by the Radiation Safety Committee
• * In the opinion of the investigators, unable to safely participate in this study and/or provide reliable data (e.g., unlikely to remain still during the imaging procedures).