SENSE (Subcutaneous and Epidural Neuromodulation System Evaluation) Study

Key Inclusion Criteria:

- Subject is 22 years of age or older

- Subject has chronic low back and leg pain secondary to Failed Back Surgery Syndrome
(FBSS)

- Subject has an average score of 6 or higher for average daily overall pain on the
Numerical Rating Scale (NRS) based on the 7 day pain diary

- Subject has attempted "best" medical therapy and has tried and failed at least three
documented medically supervised treatments (including, but not limited to physical
therapy, acupuncture, etc.) and has failed medication treatment from at least two
different classes

- Subject's pain-related medication regimen is stable 4 weeks prior to the baseline
evaluation

- Subject agrees not to add or increase pain-related medication throughout the 12 week
randomized evaluation phase of the study (starting at activation)

Key Exclusion Criteria:

- Subject currently participating in a clinical investigation that includes an active
treatment arm

- Subject has been implanted with a previous neuromodulation system (PNfS, SCS-PNfS or
SCS) or participated in a trial for a neuromodulation system

- Subject's overall Beck Depression Inventory II Score is > 24 or has a score of 3 on
question 9 relating to suicidal thoughts or wishes at the baseline visit

- Subject with an infusion pump or any implantable neurostimulator device

- Subject has an existing medical condition that is likely to require repetitive MRI
evaluation in the future (i.e. epilepsy, stroke, multiple sclerosis, acoustic neuroma,
tumor)

- Subject has an existing medical condition that is likely to require the use of
diathermy in the future

- Subject has peripheral vascular disease

- Subject is immunocompromised

- Subject has documented history of allergic response to titanium or silicone

- Subject has a documented history of substance abuse (narcotics, alcohol, etc.) or
substance dependency in the 6 months prior to baseline data collection

- Female candidates of child bearing potential that are pregnant (confirmed by positive
pregnancy test)