The vertebrae that form the spine are cushioned by small discs, which are round and flat, with a tough, outer layer (annulus) that surrounds a jellylike material called the nucleus. Located between each of your vertebra in the spinal column, discs act as shock absorbers for the spinal bones. Thick ligaments attached to the vertebrae hold the pulpy disc material in place.
A herniated disc is a fragment of the disc nucleus that is pushed out of the annulus into the spinal canal through a tear or rupture. Discs that become herniated usually are in an early stage of degeneration. The spinal canal has limited space, which is not large enough for the spinal nerve and the displaced herniated disc fragment. Because of the displacement, the disc presses on spinal nerves, often producing pain, which may be severe.
Although herniated discs can occur in any part of the spine, they are more common in the lower back (lumbar spine), but also occur in the neck (cervical spine). The area in which you experience pain depends on the part of the spine affected.
A single excessive strain or injury may cause a herniated disc. However, disc material degenerates naturally as you age, and the ligaments that hold it in place begin to weaken. As the degeneration progresses, a relatively minor strain or twisting movement can cause a disc to rupture.
Certain individuals may be more vulnerable to disc problems and, as a result, may suffer herniated discs in several places along the spine. Research has shown that a predisposition for herniated discs may exist in families, with several members affected.
Symptoms vary greatly depending on the position of the herniated disc and the size of the herniation. If the herniated disc is not pressing on a nerve, you may experience a low backache or no pain at all. If it is pressing on a nerve, there may be pain, numbness or weakness in the area of the body to which the nerve travels. Typically, a herniated disc is preceded by an episode of low back pain or a long history of intermittent episodes of low back pain.
Lower Back (Lumbar Spine)
Sciatica frequently results from a herniated disc in the lower back. Pressure on one or several nerves that connect to the sciatic nerve can cause pain, burning, tingling and numbness that radiates from the buttock into the leg and sometimes into the foot. Usually one side (left or right) is affected. The pain often is described as sharp and electric shock-like. It may be more severe while standing, walking or sitting. Along with leg pain, you may experience low back pain.
Neck (Cervical Spine)
Symptoms may include dull or sharp pain in the neck or between the shoulder blades, pain that radiates down the arm to the hand or fingers, or numbness or tingling in the shoulder or arm. The pain may increase with certain positions or movements of the neck.
Diagnosis is made by your doctor based on your history, symptoms, a physical examination and results of tests, including:
- CT scan
- Electromyogram and nerve conduction studies (EMG/NCS)
Fortunately, the majority of herniated discs do not require surgery. However, a very small percentage of people with herniated, degenerated discs may experience symptomatic or severe and incapacitating low back pain, which significantly affects their daily life.
The initial treatment for a herniated disc usually is conservative and nonsurgical. Your doctor may prescribe bed rest or advise you to maintain a low, painless activity level for a few days to several weeks. This helps the spinal nerve inflammation to decrease.
Your doctor may recommend nonsteroidal anti-inflammatory medication if the pain is only mild to moderate. An epidural steroid injection may be performed using a spinal needle under x-ray guidance to direct the medication to the exact level of the disc herniation.
Your doctor may also recommend physical therapy. The therapist will perform an in-depth evaluation, which, combined with the doctor's diagnosis, will dictate a treatment specifically designed for patients with herniated discs. Therapy may include pelvic traction, gentle massage, ice and heat therapy, ultrasound, electrical muscle stimulation and stretching exercises. Pain medication and muscle relaxants also may be beneficial in conjunction with physical therapy.
If conservative treatment options, such as physical therapy and medications, do not reduce or end the pain, your doctor may recommend surgery and, depending on your specific condition, will help to determine what procedure might be an appropriate treatment for you. As with any surgery, your age, overall health and other issues will be taken into consideration.
Surgical treatment available includes:
- Artificial disc surgery, or surgical replacement of a diseased or herniated lumbar disc with a manufactured disc
- Discectomy, or surgical removal or partial removal of an intervertebral disc
- Laminectomy, or surgical removal of most of the bony arch or lamina of a vertebra
- Laminotomy, in which an opening is made in a lamina to relieve pressure on the nerve roots
- Spinal fusion, in which bone is grafted onto the spine, creating a solid union between two or more vertebrae, and in which instrumentation such as screws and rods may be used to provide additional spinal support
The benefits of surgery always should be weighed carefully against its risks. Although a large percentage of patients with herniated discs report significant pain relief after surgery, there is no guarantee that surgery will help every individual.
Source: American Association of Neurological Surgeons