Lumbar spinal stenosis (LSS) is a common cause of low back pain and the leading indication for lumbar surgery in the United States for persons over 65 years of age [1-5]. Patients with this condition typically experience pain and paresthesias in the lumbar region, buttocks and legs [2]. The primary symptom pattern of lumbar stenosis is known as neurogenic intermittent claudication. The clinical hallmark of neurogenic intermittent claudication is pain elicited with erect postures, such as when standing and walking.

Spinal stenosis is one of the most frequent surgical diagnoses of the lumbar spine. Surgery has been reported to improve both leg and back pain in up to 60% of the patients after the first postoperative year. Outcome studies of lumbar laminectomy reveal that up to one third of patients undergoing these procedures, most often to relieve symptoms of NIC, do not experience significant pain relief or improvement in function [8]. It is quite likely that outcomes could be further optimized with better defined diagnostic criteria and indications for surgery [6]. There is significant uncertainty as to which patients will benefit from surgery as suggested by the wide geographic variation in the rates and types of surgery for this condition [7]. For older patients at risk for perioperative complications, for those with moderate symptom severity, and for the growing elderly population of patients with late recurrence of NIC after decompressive laminectomy, there is a surging unmet need for mechanism-based diagnostic strategies and novel analgesic therapies [8].