Lumbar Spinal Stenosis

Another result of degeneration of the spine is lumbar spinal stenosis (LSS). This process involves a narrowing of the canal that houses the spinal cord and nerve roots. Because the spinal canal is narrowing, the entire spinal cord is often being compressed, not just a single nerve. The compression can cause irritation and reduced blood flow within the nerve.

The image on the left shows a normal round spinal canal; the image on the right shows two locations where stenosis occurs, in the central canal and in the outer aspect (lateral recess).

Patients who suffer from LSS often experience weakness and pain in the legs, a dull pain in the lower back when they walk or stand, numbness or pins and needles in their legs or buttocks when they walk or stand, and often get relief when sitting or bending forward when they walk or leaning on a shopping cart. Symptoms of LSS usually occur in patients over the age of 50.


Once a diagnosis has been confirmed and the severity of the stenosis has been assessed, the physician will explore the most appropriate avenue of treatment, including medications, epidural steroid injections, physical therapy and surgery. Many patients respond well to conservative treatment for quite a few years. Surgery may be necessary at some point in time and can provide as much as an 80% success rate in improvement in quality of life.

This MRI demonstrates tightness (stenosis) within the lumbar spine (low back) at three different levels, from both disk protrusions and from ligament thickening.