A herniated nucleus pulposus is a slipped disk along the spinal cord. The condition occurs when all or part of the soft center of a spinal disk is forced through a weakened part of the disk.

The bones (vertebrae) of the spinal column run down the back, connecting the skull to the pelvis. These bones protect nerves that come out of the brain and travel down the back and to the entire body. The spinal vertebrae are separated by disks filled with a soft, gelatinous substance, which provide cushioning to the spinal column. These disks may herniate (move out of place) or rupture from trauma or strain.

The spinal column is divided into several segments: the cervical spine (the neck), the thoracic spine (the part of the back behind the chest), the lumbar spine (lower back), and sacral spine (the part connected to the pelvis that does not move).

Radiculopathy refers to any disease affecting the spinal nerve roots. A herniated disk is one cause of radiculopathy (sciatica).

Most herniation takes place in the lower back (lumbar area) of the spine. Lumbar disk herniation occurs 15 times more often than cervical (neck) disk herniation, and it is one of the most common causes of lower back pain. The cervical disks are affected 8% of the time and the upper-to-mid-back (thoracic) disks only 1 - 2% of the time.

Nerve roots (large nerves that branch out from the spinal cord) may become compressed, resulting in neurological symptoms, such as sensory or motor changes.

Disk herniation occurs more frequently in middle-aged and older men, especially those involved in strenuous physical activity. Other risk factors include any congenital conditions that affect the size of the lumbar spinal canal.

SYMPTOMS OF HERNIATED LUMBAR DISK

• Muscle spasm
• Muscle weakness or atrophy in later stages
• Pain radiating to the buttocks, legs, and feet
• Pain made worse with coughing, straining, or laughing
• Severe low back pain
• Tingling or numbness in legs or feet

SYMPTOMS OF HERNIATED CERVICAL DISK

• Arm muscle weakness
• Deep pain near or over the shoulder blades on the affected side
• Neck pain, especially in the back and sides
• Increased pain when bending the neck or turning head to the side
• Pain radiating to the shoulder, upper arm, forearm, and rarely the hand, fingers, or chest
• Pain made worse with coughing, straining, or laughing
• Spasm of the neck muscles

A physical examination and history of pain may be all that is needed to diagnose a herniated disk. A neurological examination will evaluate muscle reflexes, sensation, and muscle strength. Often, examination of the spine will reveal a decrease in the spinal curvature in the affected area.

Leg pain that occurs when you sit down on an exam table and lift your leg straight up usually suggests a herniated lumbar disk.

A foraminal compression test of Spurling is done to diagnose cervical radiculopathy. For this test, you will bend your head forward and to the sides while the health care provider provides slight downward pressure to the top of the head. Increased pain or numbness during this test is usually indicative of cervical radiculopathy.

DIAGNOSTIC TESTS

• EMG may be done to determine the exact nerve root that is involved.
• Nerve conduction velocity test may also be done.
• Myelogram may be done to determine the size and location of disk herniation.
• Spine MRI or spine CT will show spinal canal compression by the herniated disk.
• Spine x-ray may be done to rule out other causes of back or neck pain. However, it is not possible to diagnosis herniated disk by spinal x-ray alone.

The main treatment for a herniated disk is a short period of rest with pain and anti-inflammatory medications, followed by physical therapy. Most people who follow these treatments will recover and return to their normal activities. A small number of people need to have further treatment, which may include steroid injections or surgery.

MEDICATIONS

Nonsteroidal anti-inflammatory medications (NSAIDs) and narcotic pain killers will be given to people with a sudden herniated disk caused by some sort of injury (such as a car accident or lifting a very heavy object) that is immediately followed by severe pain in the back and leg.

If the patient has back spasms, muscle relaxants are usually given. On rare occasions, steroids may be given either by pill or directly into the blood through an IV.

NSAIDs are used for long-term pain control, but narcotics may be given if the pain does not respond to anti-inflammatory drugs.

LIFESTYLE CHANGES

Any extra weight being carried by an individual, especially up front in the stomach area, will make back pain worse. Diet and exercise are crucial to improving back pain in overweight patients.

Physical therapy is important for nearly everyone with disk disease. Therapists will tell you how to properly lift, dress, walk, and perform other activities. They will also work on strengthening the muscles of the abdomen and lower back to help support the spine. Flexibility of the spine and legs is taught in many therapy programs.

Some health care providers recommend the use of back braces to help support the spine. However, overuse of these devices can weaken the abdominal and back muscles, leading to a worsening of the problem. Weight belts can be helpful in preventing injuries in those whose work requires lifting of heavy objects.

INJECTIONS

Steroid injections into the back in the area of the herniated disk can help control pain for several months. Such injections reduce swelling around the disk and relieve many symptoms. Spinal injections are usually done on an outpatient basis, using x-ray or fluoroscopy to identify the area where the injection is needed.

SURGERY

Surgery may be an option for the few patients whose symptoms persist despite other treatments.

Diskectomy removes a protruding disk. This procedure requires general anesthesia (asleep and no pain) and 2 - 3 day hospital stay. You will be encouraged to walk the first day after surgery to reduce the risk of blood clots.

Complete recovery takes several weeks. If more than one disk needs to be taken out or if there are other problems in the back besides a herniated disk, more extensive surgery may be needed. This may require a much longer recovery period.

Other surgical options include microdiskectomy, a procedure removing fragments of nucleated disk through a very small opening.

Chemonucleolysis involves the injection of an enzyme (called chymopapain) into the herniated disk to dissolve the protruding gelatinous substance. This procedure may be an alternative to diskectomy in certain situations.

Most people will improve with conservative treatment. A small percentage may continue to have chronic back pain even after treatment.

It may take several months to a year or more to resume all activities without pain or strain to the back. People with certain occupations that involve heavy lifting or back strain may need to change job activities to avoid recurrent back injury.

• Long-term back pain
• Loss of movement or sensation in the legs or feet
• Loss of bowel and bladder function
• Permanent spinal cord injury (very rare)

Call your health care provider if persistent, severe back pain develops, especially if you have any numbness, loss of movement, weakness, or bowel or bladder changes.

Safe work and play practices, proper lifting techniques, and weight control may help to prevent back injury in some people.