Clinical Trial of MED HF10™ Spinal Cord Stimulation for the Treatment of Chronic Pain

Inclusion Criteria:

1. Have been diagnosed with chronic, intractable pain of the back pain with or withoutleg pain

2. Have been implanted with the Nevro Senza™ or Omnia SCS system with dual leads,approximately over vertebral T8-T11, for at least 3 months, and are using the systemwith single area, continuous 10 kHz stimulation programs at least 18 hours daily, asdetermined by subject reporting and confirmation via device diagnostics, for atleast 21 days prior to enrolling in this study

3. If taking them, be on stable chronic pain medications, as determined by theInvestigator, for at least 28 days prior to enrolling in the study and be willing tostay on those medications with no dose adjustments until study completion or studywithdrawal, whichever comes first.

4. Be 18 years of age or older at the time of enrollment

5. Be willing and able to comply with study-related requirements, procedures, andvisits

6. Be capable of subjective evaluation, able to read and understand IRB approvedwritten questionnaires, and are able to read, understand and sign the IRB approvedwritten informed consent, all of which will be in American English

7. Be compliant in using the patient programmer and recharger as determined by theInvestigator.

8. As determined by the Investigator, be compliant in adjusting programs using thedevice remote control.

9. Have >= 30% pain relief in primary pain area intended to be treated by SCS.

Exclusion Criteria:

1. Have a medical condition or pain in other area(s), not intended to be treated withSCS, that could interfere with study procedures, accurate pain reporting, and/orconfound evaluation of study endpoints, as

2. Have evidence of an active disruptive psychological or psychiatric disorder or otherknown condition significant enough to impact perception of pain, compliance ofintervention and/or ability to evaluate treatment outcome.

3. Have a current diagnosis of a progressive neurological disease such as multiplesclerosis, chronic inflammatory demyelinating polyneuropathy, rapidly progressivearachnoiditis, rapidly progressive diabetic peripheral neuropathy, brain or spinalcord tumor, central deafferentation syndrome, Complex Regional Pain Syndrome, oracute herniating disc, as determined by the investigator.

4. Having any clinical evidence mechanical instability or progressive neurologicpathology that warrants surgical intervention.

5. Having undergone an interventional procedure and/or surgery to treat back or legpain other than Senza HF10 therapy in the last 30 days

6. Have a condition currently requiring or likely to require diathermy

7. Have a condition currently requiring or likely to require surgery during the studyperiod.

8. Have metastatic malignant disease or active local malignant disease

9. Have a life expectancy of less than 1 year

10. Have an active systemic or local infection

11. Be pregnant or planning to become pregnant during the course of the study (if femaleand sexually active, subject must be using a reliable form of birth control, besurgically sterile or be at least 2 years post-menopausal)

12. Have within 6 months of enrollment a significant untreated addiction to dependencyproducing medications or have been a substance abuser (including alcohol and illicitdrugs)

13. Be concomitantly participating or planned to be participating in another clinicalstudy overlapping in time with the present clinical study

14. Have an existing drug pump and/or another active implantable device (switched On orOff) such as a pacemaker or other non-Senza™ SCS devices

15. Have an unresolved condition of device-related pain (e.g. IPG pocket

16. Have a condition currently requiring or likely to require surgery during the studyperiod.