Please select the eligibility criteria that correspond to the clinical trial below.
Title: Comparison of Effectiveness of Tonic, High Frequency and Burst Spinal Cord Stimulation in Chronic Pain Syndromes: a Double-blind, Randomised, Cross-over, Placebo Controlled Trial
Brief Summary: Spinal cord stimulation (SCS) is one of the most commonly undertaken neuromodulatory surgery techniques in the treatment of neuropathic pain. The indication for SCS is an ineffective conservative treatment of chronic pain syndromes. The effectiveness of SCS in the case of neuropathic pain is high. The positive result of SCS treatment is the reduction of previous painful symptoms by min. 50% and / or a reduction in the amount of taken analgesics and an improvement in the quality of life including sleep quality. Long-term studies estimate that in a properly selected group of patients more than 50% of patients achieve pain reduction by the required 50% and about 60% - 70% have an improvement in the quality of life and a reduction of pain.

The efficacy of SCS in different modes of stimulation is evaluated. Patients receive four different types of stimulation for 2-week period - not knowing what kind of stimulation it is. It is said that in one type of stimulation they would feel parestesias and in other three they would not. Patients are not informed that beside tonic, burst and high frequency stimulation, the fourth is an off stimulation to check for placebo effect. The test is double-blinded


Options:
A: Inclusion Criteria:

* Age ≥ 18 years or ≤ 80 years.
* Subject has FBSS and does not require further surgery. For the purposes of this study, FBSS is defined as persistent or recurrent low back and leg pain of at least 6 months duration following at least one decompression and/or fusion procedure.
* Subject has persistent low back and leg pain despite other treatment modalities (pharmacological, surgical, physical, or psychological therapies) that have been tried and did not prove satisfactory or are unsuitable or contraindicated for the subject.
* Average global pain is ≥ 50 mm as assessed by the baseline VAS.
* With significant back, with mean intensity on a back pain VAS ≥ 50 mm (mean daily VAS score calculated on 5 consecutive days).
* Meeting the criteria for spinal cord stimulation test according to HAS guidelines (multidisciplinary consultation, psychological assessment, etc.).
* Subject is a candidate for SCS.
* Absence of active psychosis or history of serious psychotic illness requiring hospitalisation.
* Understands and accepts the constraints of the study.
* Free subject, not under temporary or permanent guardianship and not subject to subordination.
* Patients covered by French national health insurance.
* Patients who have given their written consent to the study after having received clear information.

Exclusion Criteria:

* Age \< 18 years or \> 80 years
* Subject is or has been treated with SCS, subcutaneous or peripheral nerve stimulation, an intrathecal drug delivery system, requires back surgery at the location related to his/her original back pain complaint or experimental therapies.
* Cause of low back pain accessible to etiological "mechanical" surgical treatment (discogenic low back pain, vertebral instability, spinal deformity, etc.).
* Subject had most recent back surgery less than 6 months ago.
* Presenting a surgical, anaesthetic or psychiatric contraindication to implantation of a spinal cord stimulation system.
* Based on the opinion of the principal or sub-investigator, the subject is unable to operate the SCS equipment.
* Subject has a life expectancy of less than 24 months beyond study enrolment.
* Absence of signature of the informed consent form.
* Patients not covered by French national health insurance.
* Subjects requiring closer protection, i.e. minors, pregnant women, nursing mothers, subjects deprived of their freedom by a court or administrative decision, subjects admitted to a health or social welfare establishment, major subjects under legal protection, and finally patients in an emergency setting.
* Pregnant women, nursing mothers, women of childbearing potential not using effective contraception (hormonal/barrier: oral, parenteral, percutaneous, implantable, intrauterine device, or surgical: tubal ligation, hysterectomy, total ovariectomy).
B: Inclusion Criteria:

* Has chronic refractory pain associated with one of the conditions currently approved for spinal cord stimulation as follows: Failed Back Syndrome, Degenerative Disk Disease (DDD), Herniated Disk pain refractory to conservative and surgical interventions, Peripheral Causalgia, Complex Regional Pain Syndrome (CRPS) or Reflex Sympathetic Dystrophy (RSD).
* Primary pain in the lower half of the body.

Exclusion Criteria:

* Requires, or will in the future, diathermy treatments.
* Had implanted spinal cord stimulation system within the last six months.
C: Inclusion Criteria:

* At least 18 years old at the time of informed consent
* Willing and able to provide a signed and dated informed consent
* Capable of comprehending and consenting in English
* Willing and able to comply with all study procedures, study visits, and be available for the duration of the study
* On a stable dose (no new, discontinued or changes in) of all prescribed pain medications and willing/able to maintain or only decrease the dose of all prescribed pain medications
* Tried appropriate conventional medical management for their pain
* Not indicated for additional surgical treatment in the opinion of the referring physician or spinal surgeon
* Undergone previous spinal surgery
* Diagnosed with FBSS with appropriate pain score
* Primary pain at appropriate spinal level

Exclusion Criteria:

* Has an active implanted device, whether turned on or off
* Displays current signs of a systemic infection
* Pregnant or lactating, inadequate birth control, or the possibility of pregnancy during the study
* Has untreated major psychiatric comorbidity
* Has serious drug-related behavioral issues
* Has neurological abnormalities unrelated to Failed Back Surgery Syndrome
* Diagnosed with Raynaud disease
* Diagnosed with Fibromyalgia
* Has any active malignancy or has been diagnosed with cancer and has not been in remission for at least 1 year prior to screening
* Has secondary gains which, in the opinion of the investigator, are likely to interfere with the study
* Participating or planning to participate in another clinical trial
* Has characteristics/limits of household or close contacts involved in study (eg, family member already a study participant where blind could be broken)
D: Inclusion Criteria:

1. FBSS, CRPS patients with neuropathic and mixed pain in low-back and/or legs refractory to conservative therapy
2. Chronic pain as a result of FBSS that exists for at least 6 months
3. ≥ 18 years of age
4. Written consent of the patient to participate in study procedures.

Exclusion Criteria:

1. Active malignancy
2. Addiction to any of the following: drugs, alcohol and/or medication
3. Evidence of an active disruptive psychiatric disorder or other known condition significant enough to impact perception of pain, compliance to intervention and/or ability to evaluate treatment outcome as determined by investigator
4. Local infection or other skin disorder at site of surgical incision
5. Pregnancy

Answer: D