Inclusion Criteria:

• Patients with chronic, refractory*, primary axial back pain who based on consultation with a spine surgeon or neurosurgeon:
  • Are not candidates for or are not eligible for major lumbar spine surgery (such as fusion, microdiscectomy, laminectomy, arthroplasty, etc.); or
  • Present with spinal conditions for which surgery is typically indicated**, but must not be considered eligible for surgery due to lack of severity, lack of clearly identifiable structural cause, lack of desire to undergo major lumbar surgery, or other factors.
• Pain should have a predominant neuropathic component as per the investigator’s clinical assessment.
• Have not had any surgery for back or leg pain, or any surgery resulting in back or leg pain.
• Considering daily activity and rest, have average back pain intensity of ≥ 5 out of 10 cm on the Visual Analog Scale (VAS) at enrollment.
• Be on stable pain medications, as determined by the Investigator, for at least 28 days prior to assessing pain intensity as described in inclusion criterion #4 above.
• Be 18 years of age or older at the time of enrollment.
• Be willing and capable of giving informed consent.
• Be willing and able to comply with study-related requirements, procedures, and visits.
• Be capable of subjective evaluation, able to read and understand written questionnaires in the local language and are able to read, understand and sign the written inform consent.
• Have adequate cognitive ability to use a patient programmer and recharger as determined by the Investigator.
  • *Pain is defined as refractory, regardless of etiology, when conventional medical management has failed to reach treatment goals that may include adequate pain reduction and/or improvement in daily functioning or have resulted in intolerable adverse effects. 
  • **Degenerative disc disease, neurogenic claudication, radiculopathy, progressive motor or neurological loss, severe degenerative scoliosis, spondylosis disc herniation, spinal or foraminal stenosis, spinal instability, spondylolisthesis, pseudo-arthrosis, or other conditions.

Exclusion Criteria:

• Have a diagnosed back condition with inflammatory causes of back pain (e.g., ankylosing spondylitis or diseases of the viscera).
• Have a medical condition or pain in other area(s), not intended to be treated with SCS, that could interfere with study procedures, accurate pain reporting, and/or confound evaluation of study endpoints, as determined by the Investigator.
• Have evidence of an active disruptive psychological or psychiatric disorder identified as the primary condition or other known condition significant enough to impact perception of pain, compliance of intervention and/or ability to evaluate treatment outcome, as determined by the investigator in consultation with a psychologist.
• Have a current diagnosis of a progressive neurological disease, spinal cord tumor, or severe/critical spinal stenosis.
• Have a current diagnosis of a coagulation disorder, bleeding diathesis, progressive peripheral vascular disease or uncontrolled diabetes mellitus that would add unacceptable risk to the procedure.
• Be benefitting within 30 days prior to enrollment from an interventional procedure to treat back and/or leg pain.
• Have an opioid addiction or drug seeking behavior as determined by the Investigator.
• Have an existing drug pump and/or SCS system or another active implantable device such as a pacemaker.
• Have prior experience with neuromodulation devices (SCS, PNS, DRG, multifidus muscle stimulation).
• Have a condition currently requiring or likely to require the use of diathermy or MRI that is inconsistent with Senza system guideline in the Physician’s Manual.
• Have metastatic malignant disease or active local malignant disease.
• Have a life expectancy of less than 1 years.
• Have an active systemic or local infection.
• Be pregnant (participants of child-bearing potential that are sexually active must use a reliable form of birth control).
• Have within 6 months of enrollment a significant untreated addiction to dependency producing medications or have been a substance abuser (including alcohol and illicit drugs).
• Be concomitantly participating in another clinical study.
• Be involved in an injury claim under current litigation.
• Have a pending or approved worker’s compensation claim.