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:

* Male or female participants aged 18 years or older (no upper age limit) and willing to provide informed consent
* Participant is able and willing to comply with the follow-up schedule and protocol
* Participants diagnosed with persistent refractory visceral pain secondary to chronic pancreatitis for at least 6 months with or without dermal hyperalgesia or allodynia
* Minimum baseline pain score of 6 on eleven point NRS scale (0-10) for their visceral pain
* Previously tried and failed at least one conservative treatment for chronic pain including but not limited to pharmacological therapy, physical therapy and interventional pain procedures for persistent pain
* Been deemed suitable for the study by the pancreatic or pain MDT
* Total daily dose of opioids equivalent to ≤120mg of Morphine or 50% reduction in opioid dose. If the patients are taking more than this dose, they will be offered a referral to our opioid reduction clinic to achieve the target opioid dose and the baseline opioid will be taken as the dose on referral
* In the investigators opinion, the patient is a suitable candidate for Spinal Cord Stimulation

Exclusion Criteria:

* Female participants of childbearing potential who are pregnant/nursing or plan to become pregnant during the course of the trial
* Escalating or changing pain condition within the past month as evidenced by investigator examination
* Sphlanchnectomy or radiofrequency treatment within the past 6 months
* Currently has an active implantable device including pacemakers, spinal cord stimulator or intrathecal drug delivery system
* In the investigators opinion has an active infection
* Participated in another clinical investigation within 30 days
* Medical co-morbidities that preclude surgical intervention
* Patient is incapable of understanding or operating the patient programmer handset
* Patient is morbidly obese (BMI ≥ 40)
* Participant has a current or previous condition, which will probably require MRI investigation sometime in the following 2 years
* Participant has had a spinal surgical procedure or has spinal pathology that would significantly impede lead implantation at the level planned for implantation
* Participant has another persistent painful condition other than persistent refractory visceral pain secondary to chronic pancreatitis.
* History of alcohol abuse in the last year or IV drug abuse in the last three years.
* No increases of more than 40% from baseline amylase and lipases
C: Inclusion Criteria:

1. Have been clinically diagnosed with painful diabetic neuropathy (PDN) of the lower limbs.
2. Average pain intensity of ≥ 5 out of 10 cm on the VAS in the lower extremities at enrollment.
3. Have stable neurological status.
4. Be on a stable analgesic regimen.
5. Be 22 years of age or older at the time of enrollment.
6. Be an appropriate candidate for the surgical procedures required in this study.
7. Be capable of subjective evaluation, able to read and understand English-written questionnaires, and able to read, understand and sign the written informed consent in English.
8. Be willing and capable of giving informed consent.
9. Be willing and able to comply with study-related requirements, procedures, and scheduled visits.

Exclusion Criteria:

1. Have a diagnosis of a lower limb mononeuropathy, have had a lower limb amputation, or have large (≥3 cm) and/or gangrenous ulcers of the lower limbs.
2. Have a BMI ≥ 40.
3. Currently prescribed a daily opioid dosage \> 120 mg morphine equivalents.
4. Have a medical condition or pain in other area(s), not intended to be treated in this study.
5. Have a current diagnosis of a progressive neurological disease such a multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, rapidly progressive arachnoiditis, brain or spinal cord tumor, central deafferentation syndrome, Complex Regional Pain Syndrome, acute herniating disc, severe spinal stenosis and brachial plexus injury.
6. Have a current diagnosis or condition such as a coagulation disorder, bleeding diathesis, platelet dysfunction, low platelet count, severely diminished functional capacity due to underlying cardiac/pulmonary disease, symptomatic uncontrolled hypertension, progressive peripheral vascular disease or uncontrolled diabetes mellitus that presents excess risk for performing the procedure.
7. Have failed prior SCS, dorsal root ganglion (DRG) stimulation, or peripheral nerve stimulation (PNS) trials for chronic intractable pain.
8. Have significant spinal stenosis, objective evidence of epidural scarring and/or any signs or symptoms of myelopathy.
9. Any previous history of surgery on the posterior elements (laminectomy, posterior fusion) resulting in a compromised epidural space.
10. Be benefitting from an interventional procedure and/or surgery to treat lower limb pain.
11. Have an existing drug pump and/or another active implantable device such as a pacemaker.
12. Have a condition currently requiring or likely to require the use of diathermy or MRI that is inconsistent with Senza system guidelines in the Physician's Manual.
13. Have either a metastatic malignant neoplasm or untreated local malignant neoplasm.
14. Have a life expectancy of less than one year.
15. Have a local infection at the anticipated surgical entry site or an active systemic infection.
16. Be pregnant or plan to become pregnant during the study. Women of childbearing potential who are sexually active must use a reliable form of birth control, be surgically sterile, or be at least 2 years post-menopausal.
17. Have within 6 months of enrollment a significant untreated addiction to dependency producing medications, alcohol or illicit drugs.
18. Be concomitantly participating in another clinical study.
19. Be involved in an injury claim under current litigation.
20. Be a recipient of Social Security Disability Insurance (SSDI).
21. Have a pending or approved worker's compensation claim.
22. Have evidence of an active disruptive psychological or psychiatric disorder or other known condition significant enough to impact perception of pain, compliance with intervention and/or ability to evaluate treatment outcome.
D: Key Inclusion Criteria:

* Chronic low back pain, with or without leg pain, for at least 6 months
* Received at least 90 days of documented pain management care to address the primary pain complaint, prior to Screening (e.g. medication, physical therapy)
* If female of childbearing potential: not pregnant, as evidenced by a negative pregnancy test at Screening
* Subject signed a valid, IRB-approved informed consent form (ICF) provided in English

Key Exclusion Criteria:

* Primary pain complaint of vascular origin (e.g. peripheral vascular disease)
* Require implantation of lead(s) in the cervical epidural space
* Significant cognitive impairment at Screening that, in the opinion of the Investigator, would reasonably be expected to impair the study candidate's ability to assess pain intensity
* Previous failed spinal cord stimulation trial or is already implanted with an active implantable device(s) (e.g. pacemaker, drug pump, implantable pulse generator)

Answer: A