Please select the eligibility criteria that correspond to the clinical trial below.
Title: Spinal Cord Stimulation for Refractory Pain in Erythromelalgia
Brief Summary: Erythromelalgia is a rare disorder characterized by red, warm, and painful extremities, which is often precipitated by warm conditions. The pathophysiology is incompletely understood. The management of pain in erythromelalgia is challenging as no single therapy has been found to be effective. Response to pharmacotherapy varies, meaning that the physician has to take a stepwise trial and error approach with each patient. Consequently, this disorder is often associated with poorer health-related quality of life. There is currently no consensus or guideline on management of pain in erythromelalgia. Spinal cord stimulation is a widely applied therapy to treat severe chronic pain of various origin. Case reports and anecdotal evidence suggest that this therapy might alleviate refractory pain in patients with erythromelalgia.

The aim of this trial is to evaluate the efficacy of spinal cord stimulation for refractory pain in erythromelalgia.


Options:
A: Inclusion Criteria:

1. A diagnosis of primary or idiopathic erythromelalgia
2. Patients ≥18 years who have developed chronic pain that has remained refractory to medical treatment for ≥6 months.
3. Minimum pain intensity of 5/10 on a numeric rating scale NRS at baseline.
4. Successful two-week SCS testing period with tonic stimulation (≥2 points reduction in pain NRS from baseline). This means patients will experience paresthesia during the trial period of spinal cord stimulation.

Exclusion Criteria:

1. Coexisting conditions that would increase procedural risk (e.g., sepsis, coagulopathy).
2. History of laminectomy or posterior fusion at the thoracolumbar junction, where percutaneous electrode end tips are routinely placed.
3. Abnormal pain behavior and/or unresolved psychiatric illness.
4. Unresolved issues of secondary gain or inappropriate medication use.
5. Unfit for participation for any other reason as judged by the study physician.
B: Inclusion Criteria:

1. Patient must be willing and able to provide written informed consent prior to any clinical investigation-related procedure.
2. Age ≥ 18 years
3. Patient has chronic (at least 6 months), refractory axial low back pain with a neuropathic component and is not a candidate for spine surgery
4. Patient has back pain for ≥ 6 months inadequately responsive to supervised conservative care
5. Patient has not had spine surgery for back or leg pain
6. Patient is a candidate for spinal cord stimulation
7. Low back pain ≥ 6 on Numerical Rating Scale
8. Oswestry Disability Index score of ≥ 30%
9. Willing and able to comply with the instructions for use, operate the study device, and comply with this Clinical Investigation Plan

Exclusion Criteria:

1. Pathology seen on imaging tests obtained within the past 12 months that is clearly identified and is likely the cause of the CLBP, that can be addressed with surgery.
2. Primary complaint of leg pain, or leg pain is greater than back pain
3. Back pain is due to any of the following:

   * spinal instability defined as \> 2 mm translation on radiographic imaging
   * visceral causes (e.g., endometriosis or fibroids)
   * vascular causes (e.g., aortic aneurysm)
   * spinal infection (e.g., osteomyelitis)
   * inflammation or damage to the spinal cord (e.g. arachnoiditis or syringomyelia)
   * tumor or spinal metastases
4. Has widespread pain (e.g. fibromyalgia) or pain in other area(s), not intended to be treated in this study (e.g. neck pain, shoulder pain)
5. Patient has seronegative spondyloarthropathy (e.g. rheumatoid, lupus, psoriatic)
6. Neurological deficit (e.g. foot drop)
7. Prior lumbar spine surgery or sacroiliac joint fusion
8. Patient has used a morphine equivalent daily dose of more than 50 MME in the last 30 days
9. Patient is bed bound
10. Patients with regular intake of systemic steroids (except inhaled steroids used to treat asthma)
11. Imaging (MRI, CT, X-ray) findings within the last 12 months that contraindicates lead placement
12. Known allergic reaction to implanted materials
13. Severe scoliotic deformity (\>11 degrees in thoracic or lumbar spine)
14. Patient has a history of, or existing intrathecal drug pump
15. Patient has previous experience with neuromodulation devices, including a failed trial
16. BMI \> 40
17. Patient is enrolled, or intends to participate, in another clinical drug and/or device study or registry that may interfere with the results of this study, as determined by Abbott personnel
18. Presence of other anatomic or comorbid conditions, or other medical, social, or psychological conditions that, in the investigator's opinion, could limit the subject's ability to participate in the clinical investigation or to comply with follow-up requirements of the clinical investigation results.
19. Failed psychological evaluation
20. Suspicion or evidence of untreated mental illness, or substance abuse
21. Patient demonstrated 2 or more Waddell's signs of nonorganic behavior
22. Patient is in current litigation for back pain/injury, or is currently receiving worker's compensation
23. Pregnant or nursing subjects and those who plan pregnancy during the clinical investigation follow-up period.

    * Female subjects of child-bearing potential must have a negative pregnancy test done within 7 days prior to enrollment/baseline visit per site standard test.
C: Inclusion Criteria:

* History, symptoms and clinical findings consistent with painful radiculopathy in lower extremity(ies) ("probable" or "definite") for at least 3 months, with or without lower back pain. The pain in the extremity(ies) must dominate.
* Understand Norwegian or Swedish language (written and spoken).
* Usual pain intensity ≥ 3.5 / 10 (NRS 0-10)

Exclusion Criteria:

Absolute

* Opioid dose \> 100 mg morphine equivalents / day
* Ongoing litigation
* Mental / psychiatric disorder that may affect treatment
* Chronic generalized pain
* Pregnancy
* Hypersensitivity to local anesthetics
* Serious or unclear medical condition such as angina pectoris, severe vascular disorder, infection, malignancy disease, bleeding disorders
* Laminectomy in or above level for planned epidural access
* Spine surgery the last 3 months

Relative

* Ongoing medication that affects coagulation or platelet function
D: Inclusion Criteria:

* Adults with Type 1 or 2 diabetes
* Patients must have pain in their lower legs or feet due to painful diabetic neuropathy that has lasted for at least 3 months

Exclusion Criteria:

* Patients must not be in poor or unstable health.

Answer: A