Lumbar Spinal Stenosis Symptoms & Treatment

What parts does the lumbar spine consist of?

The lumbar spine consists mainly of the vertebrae or bone of the spine with a disc in between each bone. There are five lumbar vertebrae (referred to as L1-5). The main part of the vertebra is called the body and is located towards the front. The disc is located between the vertebral bodies. Each disc is referred to by the bones between which it sits. For example, the L4/5 disc is located between the L4 and L5 vertebral bodies.

Behind the vertebral bodies there is a ring of bone that contains the bottom of the spinal cord which ends at L1/2 and the nerve roots. The back of this ring is made of the lamina and spinous processes to which several muscles are attached. For most of the lumbar spine, there is a group of nerve roots which trail down from the bottom of the spinal cord. The nerve roots, which are surrounded by spinal fluid and which are enclosed in a sac called the dura, are referred to as the cauda equina which translates to ‘horse’s tail’.

What is stenosis of the lumbar spine?

Stenosis of the lumbar spine refers to narrowing of the canal in the lumbar spine through which the nerves travel. Rather than the nerves having space and being surrounded by CSF (or spinal fluid) the nerves are essentially squashed together. The degree of spinal stenosis can vary from being mild to severe.

The cause of the stenosis varies. In the majority of cases, it is an accumulation of degenerative or wear and tear changes that narrows the spinal canal from each side. It typically occurs at the level of each disc and may involve multiple levels as well. In most degenerative cases, it is due to a broad bulge of the intervertebral disc, thickening of the ligaments in the spine (ligamentum flavum) and overgrowth of the facet joints on each side due to arthritic change. This normally progresses slowly over time and may be associated with the gradual onset of symptoms.

Other potential causes include a large central disc protrusion that may compress all of the nerves passing by that disc in the lumbar spine. Synovial cysts, which are pockets of degenerative material that originates from the facet joints on each side and which protrude into the spinal canal, may also cause stenosis.

What are the symptoms of stenosis?

The most common symptom of lumbar spinal stenosis is termed neurogenic claudication. This means pain, pins and needles or numbness that occurs in one or both legs that typically occur with standing in the one spot or walking for a distance. The distance may become shorter and shorter over time until the symptoms occur even at rest which is a concerning sign. The symptoms of neurogenic claudication are usually relieved by sitting for a period before the person can stand or walk for a similar distance again.

In some cases, spinal stenosis affects only one nerve in particular in which case it causes a ‘pinched nerve’ or radiculopathy. This type of pain is commonly referred to as sciatica.

If lumbar stenosis is more severe, it may cause a condition known as cauda equina syndrome which is where multiple nerve roots in the lumbar spine are compressed so as to cause weakness of the lower limbs, numbness in the areas around the perineum, that is the anus and genitals, as well as bladder and bowel dysfunction and incontinence. When this occurs, it requires urgent neurosurgical treatment.

What are the treatment options for lumbar canal stenosis?

Treatment options depend on the nature and severity of symptoms. Urgent surgery is required if there is weakness, bladder or bowel dysfunction, or other features of cauda equina syndrome.

Milder symptoms may be managed conservatively with physiotherapy. Cortisone injections are sometimes used, though their benefit in spinal stenosis is limited because the issue is often mechanical compression rather than inflammation.

If symptoms significantly impact daily life and function, surgery may be appropriate. This typically involves removing the lamina and thickened ligaments, and, if necessary, any protruding disc material to decompress the nerves. The procedure is performed through an incision in the back and is a common neurosurgical operation.

To learn more about treatments for Lumbar Spinal Stenosis, click one of the following links

Lumbar Laminectomy

Posterior Lumbar Interbody Fusion

Extreme Lateral Lumbar Interbody Fusion

What are the treatment options for lumbar canal stenosis