Prolaped or herniated disc

The shock-absorbing discs between the vertebrae (bones of the spine) consist of a strong, fibrous outer coat and soft, gelatinous core. A prolapsed disc occurs when the core pushes outwards, distorting the shape of the disc. If the outer coat ruptures, the condition is termed a herniated disc. When a disc prolapses or herniates, the surrounding tissues become inflamed and swollen. Then together with the disc, the tissues may press on a spinal nerve or the spinal cord, causing pain.

Although discs in the lower back are most often affected, herniation of the discs in the neck and rarely the upper back can occur. People between the age of 25 and 45 are most vulnerable to disc prolapse or herniation. The disorder is slightly more common in men.


What are the causes?

With age, the discs begin to dry out. They also become more vulnerable to prolapse or herniation as a result of the normal stresses of daily life and minor injuries. Sometimes, a disc is damaged by bending forwards or a sharp twisting movement, or by lifting a heavy object incorrectly.

What are the symptoms?

Symptoms of a prolapsed or herniated disc may develop gradually over a period of weeks or may appear suddenly. They may include:

- Dull pain in the affected area.
- Muscle spasm and stiffness around the affected area that makes movement difficult.

If the disc presses on a spinal nerve, you may also have the following symptoms:

- severe pain, tingling or numbness in a leg or if the neck is affected, in an arm.
- Weakness or restricted movement in the leg or arm.

The pain is frequently relieved by rest but may be made worse by sitting, coughing, sneezing, bending, or bowel movement.

What might be done?

Diagnosis is usually made from your symptoms and a physical examination. Your doctor may also arrange for you to have an X-ray, to rule out other causes of back pain, and MRI or CT scanning, which can locate the position of the prolapsed or herniated disc accurately.

Although the disc is permanently damaged, the pain usually improves over 6-8 weeks as the swelling subsides. Your doctor will probably suggest ways in which you can modify physical activities to avoid further stress on your back. He or she may also recommend painkillers and refer you for physiotherapy, which can reduce muscle spasms and speed recovery.

Rarely, pain may be relieved with traction, in which the spine is gently stretched with weights to create more space around a nerve and reduce pressure on it. Some people benefit from an epidural injection or a selective nerve root block, in which a local anesthetic, sometimes used in combination with a corticosteroid drug, is injected around the compressed nerve to decrease swelling. If the damaged disc is in the neck, a supportive collar may be helpful.

In a few cases, if bladder or bowel function is impaired due to pressure on a nerve or the spinal cord or if there is severe pain or muscle weakness, urgent surgery on the disc may be required.

MICRODISCECTOMY

Microdiscectomy is a surgical procedure used to treat a prolapsed or herniated disc pressing on a spinal nerve or the spinal cord. The protruding part of the disc is removed through an incision in the fibrous outer coat of the disc. The operation is performed under general anaesthesia and requires a brief stay in hospital.