Cervical Disc Herniation

Anatomy

The cervical spine is composed of seven bones called vertebrae that stack on one another to form a portion of the spinal column in the neck.  The vertebrae are separated by discs, flat round structures that absorb mechanical forces and serve to decrease the friction associated with movement of the spine. 

The Problem

Discs are composed of a tough, flexible fibrous outer rim and a soft, jelly-like inner core with high water content.  With aging, the water content of the discs gradually decreases and the discs become thinner and more brittle.  Fraying of the outer fibrous rim can also occur to weaken the disc.

General wear and tear, increased strain or trauma to the low back can cause the jelly-like core to push against the outer rim of the disc.  A disc herniation results when the core of the disc begins to push through the outer rim.  This process occurs to varying degrees.  The core substance can remain attached to the core as it herniates, or a portion can break off from the core as it pushes out through the outer wall.  In most cases, the herniation occurs to the rear of the disc and spine.

The pressure of the core substance against the outer wall can result in neck pain.  Once the herniation has occurred, the displaced core material can press on spinal nerves nearby.  Substances can also leak out of the injured disc to cause irritation of surrounding spinal nerves.

Diagnosis

Mechanical pressure on spinal nerves can produce numbness, tingling, pain of the shoulder, arm or hand in a predictable manner that is based on the specific spinal nerve that has been affected (See cervical radiculopathy).   Detecting changes in muscle strength and muscle stretch reflexes on physical examination can tell the physician a great deal about which nerves have been affected and, therefore, the general location of the disc herniation.  Imaging studies, including MRI, are often used to confirm the presence of disc herniation and the degree to which spinal nerves are being pinched.  

Treatment

The majority of patients with cervical disc herniation are successfully treated without surgery.  The primary goals of treatment are to speed the recovery process, restore function and educate patients about methods to prevent further episodes.

A variety of medications can be helpful in relieving pain and inflammation.  Muscle relaxants can be used as supplemental treatment.  Physical modalities, such as heat, ice or electrical stimulation can be used for acute pain control and then as needed.  Cervical traction can be useful in providing pain relief.  Exercises are progressed step-wise from range of motion to active stretching and flexibility and finally to strengthening and stabilization, as symptoms resolve.

Epidural steroid injections are useful for patients who have nerve root symptoms and are progressing slowly.  These injections can have value as both diagnostic and treatment procedures.  Epidural steroids treat pain and nerve root inflammation and can provide sufficient relief to permit an aggressive rehabilitation program.

Surgery is indicated if weakness or sensory loss develop in a pattern that follows a specific nerve root or that indicates spinal cord irritation or injury.  Surgery may also be considered if nerve root pain does not respond to non-surgical measures over time.