Along the length of the spine, small circular discs act as shock absorbers between the bony vertebrae. A disc consists of a tough outer ring that encloses a soft inner core. When a rupture occurs in the ring, the gelatinous substance of the core pushes through the tear and impinges on the canal carrying the spinal cord. According to the American Association of Neurological Surgeons, or AANS, most ruptures occur in the lower back, but they can occur anywhere along the spine.
Causes
"A single excessive strain or injury may cause a herniated disc" according to AANS. Lifting a heavy load, for example, or a falling may compress a disc severely enough to cause a tear. But most ruptures are due to the degenerative changes that occur naturally in a disc. With age, the water content of a disc decreases. The disc becomes flatter and less resilient. As the space between the vertebrae narrows, pressure on the disc increases. The annulus or outer ring weakens. A disc may be so compromised that a movement as benign as bending to tie a shoe could result in a rupture. The American Academy of Family Physicians reports that people between the ages of 30 and 50 are most at risk for a ruptured disc.
Symptoms
Pain, numbness, tingling and muscle weakness can result from a rupture.The severity of the symptoms depends on how much the disc is compressing a nerve root in the spinal canal. The symptoms' location depends on the location of the disc. A ruptured disc in the neck can cause pain, numbness and weakness in the shoulders and arms. A ruptured disc in the lower back can cause symptoms along the sciatic nerves, which travel through the buttocks and down the back of each leg. In cases where nerve compression is severe in the lowest area of the spinal cord, loss of bowel and bladder control may occur.
Diagnosis
A physician makes a diagnosis based on findings obtained during a physical examination of a patient and on results obtained from diagnostic imaging. The imaging technologies include x-ray, CT, MRI and myelography. A physician may also consider tests that measure the electrical impulses along a nerve.
Treatment
According to the AAOS, 90 percent of ruptured discs resolve with conservative treatment. Restricting physical activity and avoiding movements that aggravate symptoms are the first recommendations a physician will make. Other recommendations may include the use of ice or heat and medications to relieve pain, inflammation and muscle spasm. In some cases, an injection into the irritated area may be necessary to relieve symptoms. Physical therapy involves education, pain management and an exercise program specifically designed for a patient with a ruptured disc. With treatment, the bulge in the disc gradually contracts and symptoms subside. Any significant reduction of symptoms, however, generally takes four to six weeks.
Surgical intervention may be the only option in cases complicated by a loss of bowel and bladder control or where symptoms are debilitating.
Prevention
Patients can decrease the risk of a ruptured disc by staying fit, strengthening core muscle groups and maintaining a healthy weight; by quitting smoking, which is linked to poor circulation, a contributing factor in the degeneration of a disc; by learning safe lifting techniques, maintaining good posture and using correct body mechanics in all movements; by avoiding prolonged sitting or standing; and by limiting activities that involve repetitive bending or twisting of the back.
