- Pain consistent with a diagnosis of chronic lumbo-sacral radiculopathy due to spinal
stenosis or disk herniation.
- Radicular pain must be present for at least 3 months and pain stable for at least 4
- Surgery for lumbo-sacral radiculopathy within previous 6 months and/or more than one
previous spinal surgery for pain-radiculopathy.
- Epidural injection for lumbo-sacral radiculopathy within previous 6 weeks and/or
anticipated need for treatment with opioid analgesics, anti-epileptic medications or
tricyclic antidepressants to alleviate pain due to lumbo-sacral radiculopathy during
the course of the study.