Spinal (or spinal) stenosis is the narrowing of the spinal canal that contains the spinal cord and nerve roots.
The stenosis can cause pressure on the spinal cord and nerves that pass through the spine.
This disorder occurs most often in the neck and lumbar spine.
Spinal stenosis consists of the reduction of at least one of the two spinal spaces in which the nerves pass:
1. The canal at the center of the spine in which the spinal cord and nerve roots are contained,
2. The openings between the vertebrae (bones of the spine) through which the nerves of the spine exit and go to the other parts of the body.
There are two types of spinal stenosis: cervical stenosis and lumbar stenosis. Although lumbar stenosis is more frequent cervical stenosis is more dangerous because it causes compression of the spinal cord on top.
Who suffers from spinal stenosis?
This disorder is more common among men and women over the age of 50. However, it can occur in younger people who are born with a narrowing of the spinal canal or who have had a spinal cord injury.
What causes lumbar spinal stenosis?
The most frequent causes of lumbar spinal stenosis are osteoarthritis or disc degeneration.
As with other joints in the body, osteoarthritis often occurs in the spine as part of the normal aging process.
Osteoarthritis can cause loss of cartilage between the bones of the joints, formation of bone spurs (osteophytes), reduction of the normal height of the discs between the vertebrae of the spine (the degenerative disc disease, also known as spondylosis), and growth (hypertrophy) of the ligamentous structures.
Degeneration of the lumbar discs can cause spondylolisthesis: slippage of one vertebra over the other, which in severe cases can lead to instability and neurological symptoms.
Each of these processes can reduce the normal space available to the nerves in the spinal canal and is the direct consequence of the pressure on the nerve tissue that causes the symptoms of lumbar spinal stenosis.
Spinal stenosis can also be caused by other conditions that decrease the space of the spinal canal or vertebral foramen.
These diseases are:
- Rheumatoid arthritis . The Rheumatoid arthritis usually affects people under the age of 60 and causes inflammation of the soft tissues and joints of the synovium ( synovitis ). Although not a common cause of spinal stenosis, damage to ligaments, bones, and joints begins with synovitis. Parts of the spine with greater mobility (eg, cervical) are most affected in people with rheumatoid arthritis.
- Cancer (formation of abnormal tissue of the structures that make up the spinal canal),
- Infection ,
- Metabolic disorders of bone causing bone growth, such as Paget’s disease.
These causes, however, are much less frequent than arthrosis.
Symptoms of spinal stenosis
- Pain in the spine . People with spinal stenosis do not always have spinal pain, depending on the degree of arthrosis.
- Burning pain in the glutes and legs ( sciatica ). The pressure on the spinal nerves can cause pain in areas where the nerves arrive.
The nuisance is described as a burning sensation or pain. It usually starts in the area of the buttocks and radiates down the leg.
The pain in the spine up the leg is called sciatica.
With the progression of the disease, it can cause foot pain.
- Numbness or tingling in the buttocks to the leg. With increasing pressure on the nerve, numbness and tingling often accompany a burning pain. Not all patients will have all of these symptoms together.
- Weakness in the legs or “fall of the foot”. Once the pressure reaches a critical level, you may have weakness in one or both lower limbs. Some patients have foot drop or the feeling that the foot drags on the floor while walking.
The pain subsides when you lean forward or if you are sitting.
Studies of the lumbar spine show that forward flexion increases the space available to the nerves.
Patients feel relief lying down and sitting down.
The pain worsens standing or walking.
Some patients know that they can ride a bicycle or walk against a cart. Taking a walk between two blocks can cause very strong sciatica.
Serious cases of spinal stenosis can also cause incontinence and paralysis.
Diagnosis of spinal stenosis
The physical examination is to test the range of motion of the spine and palpation to find areas with tingling .
The legs can be examined to test the range of motion, strength, sensitivity and reflexes.
The hips and knees should be evaluated because the problems of these joints can cause symptoms similar to those of lumbar stenosis.
After the examination, the doctor may order some tests to detect the anatomical signs of lumbar spinal stenosis.
The first examination is a simple x – ray of the spine.
The doctor may also order an x-ray of the patient’s pelvis according to the suspicions that were found on the physical examination.
Radiography may show the doctor various signs associated with spinal stenosis, including loss of intervertebral disc height, presence of bone spurs (osteophytes), and spinal instability (abnormal movement between the vertebrae).
The definitive diagnosis of lumbar vertebral canal stenosis is done with an MRI or CT scan.
These advanced exams show the spinal nerves and can show if they are compressed by lumbar stenosis.
In some cases, special tests are performed for the nerves: electromyography (EMG) and nerve conduction study.
These tests may identify nerve damage or irritation that is a consequence of stenosis compression of the lumbar spine.