Discs are the relatively soft, gelatinous cushions that surround the spinal cord and act as shock absorbers between the hard, bony vertebrae. MRI studies of asymptomatic individuals indicate that 40% of patients studied have disc abnormalities.

A herniated disc is a protrusion of the disc's jelly-like center (the nucleus pulposus), through its tough, fibrous outer ring (the annulus fibrosus) usually through small openings in the vertebrae where nerves enter the spinal column.

Degenerative Disc Disease (sometimes referred to as a Black Disc) refers to the loss of hydration in the disc and a weakening of the annulus (outer lining of the disc). Degenerative Disc Disease is very common in the human population but is not always symptomatic.

Trauma can cause the annulus to tear and disc material (the nucleus pulposus) leaks out and presses on a nerve. When a disc ruptures in the cervical spine, it puts pressure on one or more nerve roots (often called nerve root compression) or on the spinal cord, as seen in (Figure 2).

In addition to pain around the site of the herniation; another hallmark of an acute disc herniation in the cervical spine is pain, numbness, or tingling radiating down the arm. Sensory deficits and weaknesses in the muscles of the arms, the thumb and some of the fingers, can present themselves, depending on the location of the affected disc. Because of the presence of the spinal cord, severe disc herniations can cause spinal cord dysfunction, which include weakness in the legs, balance problems, and loss of bladder or bowel control. Further pressure on the spinal cord may be caused by rough edges of bone, called bone spurs, that naturally build up around some herniated discs.

Several kinds of imaging tests, including X-rays, CT scans, MRI's and other more exotic imaging tests can confirm and elucidate the findings of a physical exam. In general, bulging disks are rarely a diagnostic mystery. Depending on where the herniation occurs, and the degree to which nerves entering the spine, or the spine itself, are affected, a wide range of symptoms are possible.

Click on the xray (above) to view the enlarged image

Treatment:

Generally speaking, the presentation and duration of symptoms in the cervical spine is similar to that of the lumbar spine. 60-80% of acute symptoms will resolve in 4-6 weeks with rest and other conservative measures. During this time, the spine should not be manipulated in any way. Muscle and sensory weakness or abnormality can be increased with any manipulation except longitudinal traction applied gently on the neck bones. Medications such as anti-inflammatories or a short course of low dose steroids can reduce the inflammation until the natural history of the problem resolves itself.

For patients who remain symptomatic beyond 6-8 weeks of conservative care, a decision about interventional treatment should be discussed between the patient and the physician. Increasing pain is a relative indication for surgery on the cervical spine. Muscle weakness or sensory changes which continue for 8-12 weeks or progressive neurological deficit are strong indications for surgical intervention. Signs of spinal cord compression such as balance or bowel and bladder problems are other strong indicators for aggressive intervention.