Spinal Stenosis: Causes and Effects

Spinal stenosis causes are a little more difficult to figure out than are its effects. Spinal stenosis is a term that describes the narrowing of passageways in the spinal column, and is usually present when the spine is affected by a degenerative condition like bone spurs, herniated discs, or spondylolisthesis.

That being said, spinal stenosis itself does not always cause of back pain or neck pain. This condition only becomes symptomatic when passageways constrict to the point that the spinal cord or one of the nerve roots housed within the spinal column becomes irritated as a result of the narrowing. And while it may be easy to feel stiffness in the neck or pain in the lower back and hypothesize that spinal stenosis is present, it is significantly more difficult to determine why exactly the narrowing occurred. Visiting your doctor for a diagnosis is the only way to really determine the cause.

The Underlying Causes of Spinal Stenosis

The spinal canal is where the spinal cord passes through, and in a healthy spine, the spinal cord will not touch the surrounding vertebrae or intervertebral discs. Furthermore, the spinal cord has many pairs of nerve roots that branch off and exit the spine through channels located between vertebrae. Like the spinal cord, nerve roots are supposed to have ample room to pass and will not touch surrounding bone or other tissue in a healthy spine. However, spinal abnormalities tend to move one or more pieces of the spinal anatomy into the path of nerves, thereby constricting the spinal cord or its nerve roots.

For instance, intervertebral discs can bulge into or herniate and extrude disc fluid into the spinal canal, irritating the spinal cord or nearby nerves. Vertebrae can also shift forward or backward (spondylolisthesis) into the canal. These are not the only spinal stenosis causes, though. Inflammation, bone spurs, and flattened discs can all invade space in the already crowded spinal column and contribute to the presence of spinal stenosis.

The Varying Effects and Symptoms

Spinal stenosis causes two forms of symptoms: localized and radiating. Localized symptoms are felt at the site of impingement of the spinal cord or a spinal nerve, and these symptoms tend to be pain and stiffness in the neck or lower back. Radiating symptoms are more perplexing. These symptoms can be felt away from the source of impingement, but still caused by the narrowing of nerve pathways in the spinal column. This is the case because, oftentimes, spinal stenosis can result in constriction or impingement of a nearby nerve root that extends throughout the body. When these nerve roots are impinged, they can send signals of pain along the course of that nerve and into various parts of the body. Similarly, if the nerve root's signals are blocked or interrupted, it will feel like numbness, tingling, muscle weakness, and muscle spasms in the extremities.