Spinal stenosis occurs when one or more of the bony openings in the spine (foramina) begin to narrow which reduces the space for the nerves. This process can occur in the spinal canal, where the spinal cord runs through or the intervertebral foramina, where the spinal nerves exit the spine.
Depending on the location and severity of the stenosis, a person with spinal stenosis can experience pain, tingling, numbness or weakness. The most common area for spinal stenosis is in the neck or low back.
Spinal stenosis is generally caused by wear-and-tear process of aging. Narrowing of the spinal canal or exit foramina is caused by bony spurs (osteophyes), bulging or narrowing discs and thickening and reduced elasticity of the spinal ligaments (primarily ligamentum flavum).
Less commonly, the symptoms of spinal stenosis may be experienced due to an injury causing a spinal fracture; or damage to the tissues in the spinal canal resulting in swelling that narrows the space in the spinal cord. Abnormal growths such as tumours will also narrow the space in the spinal canal resulting in the symptoms of stenosis.
Spinal stenosis is most common in people who are over 50 years old. Symptoms will vary depending on the location of the stenosis (narrowing) and which nerves are affected.
In the neck (cervical spine):
In the back (lumbar spine):
Spinal stenosis will be diagnosed based upon only upon symptoms in the majority of cases. If you are getting significant weakness, loss of balance and loss of bladder, bowel or sexual function you should have an MRI to assess the extent of stenosis and whether surgery may be required. It is not necessary to use MRI in all cases. Multiple studies have shown that people who are asymptomatic (have no symptoms) have signs of stenosis on MRI, therefore this is not a gold standard assessment but simply a part of the assessment. X-rays are used to show bony changes such as osteophytes (bony spurs) that are narrowing the space in the spinal canal.
In most cases the symptoms of spinal stenosis will be managed well using conservative methods.