As we age, the intervertebral discs in the spine may lose water and become dried out. As this happens, the disc compresses. This may lead to the deterioration of the tough outer ring allowing the nucleus, or the inside of the ring, to bulge out. This is considered a bulging disc.
Degenerative disc disease is one of the most common causes of low back and neck pain. As degenerative disc disease continues to worsen, or with continued stress on the spine, the inner nucleus pulposus may actually rupture out from the annulus. This is considered a ruptured, or herniated, disc. The fragments of disc material can then press on the nerve roots that are located just behind the disc space. This can cause pain, weakness, numbness, or changes in sensation. Most disc herniations happen at the lower lumbar spine, especially at the L4-5 and L5-S1 levels.
Degenerative disc disease can also occur in the thoracic area of the spine, most frequently at the thoracolumbar junction (where the thoracic and lumbar areas of the spinal column meet). While similar to cervical and lumbar disc disorders, thoracic lumbar disc disease is far less likely to cause symptomatic lesions. The prevalence of thoracic disc disorders is not fully understood because many do not cause back pain or other symptoms.
Causes of Disc Disease
Lumbar disc disease is due to a change in the structure of the normal disc. Most of the time, disc disease comes as a result of aging and the degeneration that occurs within the disc. Occasionally, severe trauma can cause a normal disc to herniate. Trauma may also cause an already herniated disc to worsen.
Symptoms of Degenerative Disc
The symptoms of lumbar disc disease vary depending on where the disc has herniated, and what nerve root it is pushing on. The following are the most common symptoms of lumbar disc disease. However, each individual may experience different symptoms. Symptoms may include:
- intermittent or continuous back pain (this may be made worse by movement, coughing, sneezing, or standing for long periods of time)
- spasm of the back muscles
- sciatica - pain that starts near the back or buttock and travels down the leg to the calf or into the foot
- muscle weakness in the legs
- numbness in the leg or foot
- decreased reflexes at the knee or ankle
- changes in bladder or bowel function
The symptoms of lumbar disc disease may resemble other conditions or medical problems. Always consult your physician for a diagnosis.
Diagnosis of Degenerative Disc
In addition to a complete medical history and physical examination, diagnostic procedures for lumbar disc disease may include the following:
- X-ray - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film
- magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body
- myelogram - a procedure that uses dye injected into the spinal canal to make the structure clearly visible on X-rays
- computed tomography scan (also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body; a CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.
- electromyography (EMG) - a diagnostic test that measures muscle response or electrical activity in response to a nerve's stimulation of the muscle
Degenerative Disc Treatment
Specific treatment for lumbar disc disease will be determined by your physician based on:
- your age, overall health, and medical history
- extent of the condition
- type of condition
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the condition
- your opinion or preference
Typically, conservative therapy is the first line of treatment to manage lumbar disc disease. This may include a combination of the following:
- bed rest
- patient education on proper body mechanics (to help decrease the chance of worsening pain or damage to the disc)
- physical therapy, which may include ultrasound, massage, conditioning, and exercise programs
- weight control
- use of a lumbosacral back support
- medications (to control pain and/or to relax muscles)
- epidural steroid injections
When these conservative measures fail, surgery for repair of degenerative disc disease may be recommended. The type of surgery needed will be based on your surgeon's assessment, but the most common include:
- lumbar fusion