Spinal disc herniation
A spinal disc herniation is the protrusion of soft, flabby material that makes up the central section of an intervertebral disc. This usually occurs when a tear develops along the outer perimeter of the disc. Also known as a slipped disc, a spinal disc herniation can occur at any age, but it is most commonly experienced by people over the age of 40.
Definition & Facts
The discs between the bones of the vertebrae are rubbery pads that act as cushions. The tough exterior of the disc protects the softer center. The disc itself is shaped like a ring that is thicker on the edges than in the center.
If the disc is put under too much pressure, some of the outer ring material becomes stressed. If it ruptures, some of the soft inner material can squeeze outward. A herniated disc is identified when the soft material is visible through X-rays or MRIs. In some cases, the hernia presents a danger to nerves that lie next to the vertebrae because the excess pressure compresses the nerve, leading to a pinched nerve.
Symptoms & Complaints
Pain in the lower back is often felt if the rupture presses against soft tissue containing a bundle of nerves. Symptoms of sciatica are a common complaint by individuals if the condition is located in the lumbar vertebrae. This may include constant leg pain, knee pain, or foot pain.
Unlike pain associated with muscle spasms, pain symptoms of a slipped disc are usually continuous. Sometimes, the nerves affected by the slipped disc are those that control muscle movements. If this is the case, the muscles will contract less often and to a lesser extent. This results in a weakening of the muscles and a sense of muscle fatigue noticed by the individual.
Degeneration of the disc material is the most common cause of this type of herniation. As individuals age, their bodies produce less and less inorganic material that makes up the discs between the vertebrae. Any form of undue stress on the backbone can cause a rupture. If the softer, pliable inner material of the disc is protected by weakening outer ring material, the pressure load shifts to the center. This causes the disc to change shape slightly. The result is a hernia because the outer material cannot stand up to the pressure.
Some individuals lose a portion of the water content in a disc, which results in less springiness. As the disc becomes drier, it resists pressure to a lesser and lesser degree. Trauma as a result of a serious injury - such as blunt force - can also cause a disc to rupture. This is not very common, but some types of accidents can put a great deal of stress on the vertebrae as a whole. The weakest link in the chain can feel the greatest amount of sharp pressure, and a rupture is the result.
Diagnosis & Tests
If a patient complains of back pain, numbness in the hands, legs and feet, or pain associated with a sciatic nerve problem, the doctor will check the back muscles and the tissue near the backbone for tenderness. He or she will likely order X-rays or schedule an MRI. Reflexes, muscle strength, and numbness awareness will also be checked.
A spinal disc herniation will nearly always show up on an MRI or X-rays because the protruding material can be seen quite clearly. In some cases, the patient will undergo a specialized test known as an electromyogram. This test shows how efficiently nerve signals are conducted along a nerve pathway.
If a herniated disc is to blame, the nerve impulses will weaken at the point where the hernia is affecting adjacent tissues. Sometimes, a slipped disc causes undue pressure on the spinal cord itself. The doctor may conduct a myelogram to test for this by injecting a dye into the cerebrospinal fluid. Any pressure can be seen when the dyed fluid is then subjected to X-rays.
Treatment & Therapy
Anti-inflammatory pain medications are the most common treatment prescribed for herniated discs. This is true even if the doctor determines that surgery may be necessary. After carefully studying the test results, the doctor will suggest surgery only if the protruding disc material is negatively affecting the adjacent tissues. Otherwise, the most likely long-term treatment in addition to the medications is physical therapy.
Approximately 90 percent of patients diagnosed with a slipped disc are instructed on how to conduct at-home exercise routines. This, in combination with continued pain medication prescriptions, reduces the symptoms dramatically. Physical therapists may recommend traction, therapeutic ultrasound treatment, or electrical nerve stimulation such as TENS.
Special neck braces and back braces may have to be worn for a short period of time during the recovery period. If, however, surgery is suggested, the operation involves removal of the protruding disc material. In very rare cases, the entire disc must be removed and the adjoining vertebrae fused together. An artificial disc may be surgically implanted, but this is a very rare procedure, performed on less than one percent of all herniated disc patients.
Prevention & Prophylaxis
Adhering to good safety practices when lifting or transporting heavy loads is highly recommended. Keeping a healthy weight also helps. Excess weight, even that which accumulates below the spine, puts extra pressure on the spinal cord because the individual must work harder to move around.