Spinal Stenosis is a term used to describe abnormal narrowing of spaces in the spine. This narrowing can occur in the spinal canal that holds the spinal cord and can also occur at the space where the spinal nerves emerge from the spinal cord.
Spinal Stenosis can occur anywhere in the spine but most commonly occurs in the lumbar spine (lower back) and cervical spine (neck).
What Causes Spinal Stenosis?
There are many factors that either cause or contribute to the development of spinal stenosis:
- Aging – Many changes occur in our bodies that can affect our health as we age. In the spine there are ligaments (connective tissue that hold together bones, cartilage and joints) that can thicken. As these ligaments thicken they can cause narrowing of the spinal canal. Also as we age we sometimes develop bone spurs (abnormal growth of bones) that can sometimes extend into the spaces of the spine that hold the spinal cord and nerves. There are small joints in the spine (called facet joints) that can also start to break down and form bone spurs, and this process is known as osteoarthritis. All of these factors can cause narrowing of the spaces in the spine.
- Disc Herniations – the inner “gel-like” substance of the disc can herniate (see section on Disc Herniation) and depending on the size and location of the herniation can cause narrowing of the spaces of the spine that contain the spinal cord or spinal nerves.
- Genetics – Sometimes the spinal canal that holds the spinal cord can be smaller than the normal size when we are born. This is usually hereditary and passed on from one generation to the next. In some cases symptoms of spinal stenosis can be seen in a relatively young individual.
- Instability of the spine – Injury to the bones of the spine or significant degeneration of the facet joints in our spine can displace or move one vertebra forwards or backwards, out of alignment with the rest of the vertebra. This is called “Spondylolisthesis” and can narrow the spinal canal.
- Spinal Tumors – Tumors are abnormal growths of body tissue and can be benign (not cancer) or cancerous. Abnormal tissue can grow into the spinal canal and cause narrowing. Tissue growths can also lead to loss of bone which can result in changes to the overall framework of the spine and narrowing of the spaces.
- Trauma – Accidents or traumatic injuries can result in fracture or dislocation of the spine. Some fractures can produce fragments of bone that can enter and narrow the spaces of the spine.
What Are the Symptoms of Spinal Stenosis?
Narrowing of the spinal spaces can result in constriction or “pinching” of the spinal cord and nerves. The most common symptoms of spinal stenosis are low back and leg pain that worsens with standing or walking. As the nerves of the spine control muscle power and sensation additional symptoms can include weakness resulting in frequent falling or clumsiness and numbness or tingling sensation in the legs and/or feet.