Herniated Disk

– Rupture and extrusion of the nucleus pulposus through the external ring of an intervertebral disk, causing back pain; the usual location is the lumbosacral region of the spine.

Causes and Incidence

Degenerative changes with or without accompanying trauma can lead to a weakening of the outer ring of the intravertebral disk and act as predisposing factors in the extrusion of the nucleus pulposus. The rupture is associated with severe strain or trauma. Lumbar herniation is most common and generally occurs in adults 20 to 45 years of age. Men are affected more often than women.

Disease Process

As the ruptured nucleus pulposus extrudes through the annulus fibrosus, the nucleus moves posteriorly and laterally into the extradural space. This often compresses or irritates the nerve root, causing sciatica and compression of the spinal cord, leading to corresponding muscle weakness and diminished sensation.

Symptoms

The predominant feature is pain in the lower back radiating down one leg or pain in the neck radiating down one arm, either of which may be sudden or insidious in onset. The pain is exacerbated by activity and jugular compression (caused by laughing, coughing, or straining at stool). Numbness and weakness may also be present in muscles innervated by the affected spinal nerve root.

Potential Complications

Neurologic deficits, particularly interference with bowel and bladder functioning, are the most common complications.

Diagnostic Tests

A clinical history, physical examination, and prolapse seen on a computed tomography or magnetic resonance imaging scan are used for diagnosis. Electromyography may define the particular root involved.

Treatments

Surgery
Microscopic laminectomy to remove a bulging disk when lesions are acutely compressing the spinal cord or pain is intractable.

Drugs
Analgesics and muscle relaxants to relieve pain.

General
Alternating hot and cold compresses for pain; massage; positioning to avoid strain; strict bed rest on firm surface for an acute episode, followed by structured exercise program to strengthen back and abdominal muscles; traction for cervical muscle weakness and sensory loss; back brace with lumbar origin; instruction in proper body mechanics; relaxation techniques.