Cervical Spine

Your neck is part of a long flexible column, known as the spinal column or backbone, which extends through most of your body. The cervical spine (neck region) consists of seven bones called vertebrae. These seven bones are numbered C1-C7. They are separated from one another by intervertebral discs. These discs are round and flat, with a tough, outer layer (annulus) that surrounds a jellylike material (nucleus). Discs act as shock absorbers for the spinal bones, and allow the spine to move freely.

Attached to the back of each vertebral body is an arch of bone that forms a long, continuous hollow space, which runs the whole length of your back. This space, called the spinal canal, is the area through which the spinal cord and nerve bundles pass. The spinal cord is bathed in cerebrospinal fluid (CSF) and surrounded by three protective layers called the meninges. The three layers are called the dura, arachnoid, and pia mater.

At each vertebral level, a pair of spinal nerves exit through small openings called foramina (one to the left and one to the right). These nerves serve the muscles, skin and tissues of the body and thus provide sensation and movement to all parts of the body. The delicate spinal cord and nerves are further supported by strong muscles and ligaments that are attached to the vertebrae.

Cervical disc disease

Signs of cervical disc disease may include pain in your neck or shoulder, or tingling and numbness in your arms. You may also have some weakness in your arms or hands.

Neck pain may be caused by many factors. Disc can wear out over time, called degeneration. Your spinal canal may be naturally narrow or become narrowed. Arthritis, and, in rare cases, cancer or meningitis can also cause neck pain. For serious neck problems, your primary care provider may refer you to a neurosurgeon to make an accurate diagnosis and recommend treatment.

You should seek medical evaluation by your primary care provider if your neck pain:

• It occurs after an injury or blow to the head
• Fever or headache accompanies the neck pain
• Stiff neck prevents you from touching your chin to your chest
• Pain shoots down one arm
• There is tingling, numbness or weakness in your arms or hands
• Neck symptoms associated with leg weakness or loss of coordination in arms or legs.
• Your pain does not respond to over-the-counter pain medication
• Pain does not improve after a week

Age, injury, poor posture, or diseases such as arthritis can lead to degeneration of the bones or joints of the cervical spine. Thus can lead to disc herniation or cause bone spurs to form. Sudden severe injury to the neck may also lead to disc herniation, whiplash, blood vessel destruction, vertebral injury, and, in extreme cases, permanent paralysis. Herniated discs or bone spurs may cause a narrowing of the spinal canal or the small openings through which spinal nerve roots exit.

Pressure on the spinal cord in the cervical area can be a very serious problem. Virtually all of the nerves to the rest of the body have to pass through the neck to reach their final destination (arms, chest, abdomen, legs). This can affect the function of many important organs.

Cervical stenosis

Narrowing of the spinal canal of the neck is called cervical stenosis. Cervical Stenosis occurs when the spinal canal narrows and compresses the spinal cord. This is most frequently caused by aging. The discs in the spine that separate and cushion vertebrae may dry out. As a result, the space between the vertebrae shrinks, and the discs lose their ability to act as shock absorbers. At the same time, the bones and ligaments that make up the spine become less pliable and thicken. These changes result in a narrowing of the spinal canal.

In addition, the degenerative changes associated with cervical stenosis can affect the vertebrae by contributing to the growth of bone spurs. These spurs may compress the nerve roots. Mild stenosis can be treated conservatively as long as the symptoms are restricted to neck pain. Severe stenosis requires referral to a neurosurgeon.

Symptoms

• Neck or arm pain
• Numbness and weakness in both hands
• Unsteady gait when walking
• Muscle spasms in the legs
• Loss of coordination

Diagnosis

Diagnosis is made based on your history, symptoms, a physical examination, and results of tests, including the following:

• Computed tomography scan (CT or CAT scan): A diagnostic image created after a computer reads x-rays; can show the shape and size of the spinal canal, its contents, and the structures around it.
• Electromyogram and Nerve Conduction Studies (EMG/NCS): These tests measure the electrical impulse along nerve roots, peripheral nerves, and muscle tissue. This will indicate whether there is ongoing nerve damage, if the nerves are in a state of healing from a past injury, or whether there is another site of nerve compression.
• Magnetic resonance imaging (MRI): A diagnostic test that produces three-dimensional images of body structures using powerful magnets and computer technology; can show the spinal cord, nerve roots, and surrounding areas, as well as enlargement, degeneration, and tumors.
• Myleogram: An x-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces; can show pressure on the spinal cord or nerves due to herniated discs, bone spurs or tumors.
• X-ray: Application of radiation to produce a film or picture of a part of the body can show the structure of the vertebrae and the outline of the joints.

Treatment

Nonsurgical treatment is the first approach in patients with common neck pain not involving trauma. For example, many patients with cervical disc herniations improve with conservative treatment and time and do not require surgery. Conservative treatment may include pain medication, bed rest, reduction of physical activity, and physical therapy. Your doctor may prescribe medications to reduce the pain or inflammation and muscle relaxants to allow time for healing to occur. In some cases, an injection of corticosteroids may be used to temporarily relieve pain.

Surgery

You may be a candidate for surgery if:

• Conservative therapy is not helping
• You experience progressive neurological symptoms involving your arms and legs
• You experience difficulty with balance or walking
• You are in otherwise good health

There are several different surgical procedures which may be used. The choice of which depends on the severity of your case. In a small percentage of patients, spinal instability may require that spinal fusion be performed. This is a decision that is generally determined prior to surgery. Spinal fusion is an operation that creates a solid union between two or more vertebrae. Various devices (like screws or plates) may be used to enhance fusion and support unstable areas of the cervical spine. This procedure may assist in strengthening and stabilizing the spine and may thereby help to alleviate severe and chronic neck pain.

Anterior Cervical Discectomy

This operation is performed on the neck to relieve pressure on one or more nerve roots, or on the spinal cord. The cervical spine is reached through a small incision in the anterior (front) of your neck. If only one disc is to be removed, it will typically be a small horizontal incision in the crease of the skin. If the operation is more extensive, it may require a slanted or longer incision. After the soft tissues of the neck are separated, the disc and bone spurs are removed. The space left between the vertebrae may be left open or filled with a small piece of bone through spinal fusion. In time, the vertebrae may fuse or join together.

Anterior Cervical Corpectomy

This operation is performed with the anterior cervical discectomy. The corpectomy is often done for multi-level cervical stenosis with spinal cord compression caused by bone spur formations. In this procedure, the neurosurgeon removes a part of the vertebral body to relieve pressure on the spinal cord. One or more vertebral bodies may be removed including the adjoining discs. The incision is generally larger. The space between the vertebrae is filled using a small piece of bone through spinal fusion. Because more bone is removed, the recovery process for the fusion to heal and the neck to become stable is generally longer than with anterior cervical discectomy. Your surgeon may select to use a metal plate that is screwed into the front of the vertebra to help the healing process.

Posterior Microdiscectomy

This procedure is performed through a vertical incision in the posterior (back) of your neck, generally in the middle. This approach may be considered for a large soft disc herniation that is located on the side of the spinal cord. A high speed burr is used to remove some of the facet joint, and the nerve root is identified under the facet joint. The nerve root needs to be gently moved to the side to free up the disc herniation.

Potential advantages of this procedure are that a fusion is not necessary and the recovery time may be shorter. There are several potential disadvantages. First, because the spinal cord is in the way, visualization of the disc space is limited. Generally, only a disc herniation that is off to the side of the spine can be approached. Because a fusion is not done, the disc space is not separated and the associated collapse that occurs with a disc herniation can continue and place pressure on the nerve where it exits the spine. Since the disc is not removed completely, it can herniate again in the future.

Posterior Cervical Laminectomy

This procedure requires a small incision in the middle of your neck to remove bone spur formations or disc material. The foramen, the passage in the vertebrae of the spine through which the spinal nerve roots travel, is enlarged to allow the nerves to pass through.

Your neurosurgeon will remove a section of the lamina (the back bony part of the vertebrae) and ligament to find the exact area of the compression. An operating microscope is used to create an opening, and part of the lamina is removed to take pressure off the nerves and spinal cord. If needed, bone spurs, tissue and any disc fragments causing the compression are also removed.

Risks and Outcome

Although complications are fairly rare, all surgery carries risks. The following risks may be associated with cervical spine surgery:

• Infection
• Excessive bleeding
• An adverse reaction to anesthesia
• Chronic neck or arm pain
• Inadequate symptom relief
• Damage to the nerves and nerve roots
• Damage to the spinal cord (about 1 in 10,000)
• Damage to the esophagus, carotid artery or vocal cords
• Fusion that does not heal
• Instrumentation breakage and/or failure
• Persistent swallowing or speech disturbance
• Leakage of cerebral spinal fluid

The benefits of surgery should always be weighed carefully against its risks. Although a large number of cervical spine patients report significant pain relief after surgery, there is no guarantee that surgery will help everyone.

Postsurgery

Your neurosurgery team will give you specific instructions after surgery and usually prescribe pain medication. Your neurosurgery team will also help determine when you can resume normal activities such as returning to work, driving and exercising. Some patients may benefit from supervised rehabilitation or physical therapy after surgery. Discomfort is expected while you gradually return to normal activity, but pain is a warning signal that you might need to slow down.

Every surgery case is different and unique. Your recovery and outcome from any surgical procedure depends on many factors, including any other chronic health problems you hay have, your understanding and cooperation of your postsurgical instructions, social habits such as smoking or alcohol use, and other factors. Be sure to discuss your specific case with your neurosurgery team, so you will have a better understanding of what to expect after surgery.

While complications are rare, you should pay close attention to the information provided by your neurosurgical team after surgery, so you are familiar with potential warning signs of any complication.

Illustration courtesy National Institutes of Health-NHLBI. Other content is provided courtesy of the American Association of Neurological Surgeons, www.neurosurgerytoday.org, and edited by Johnny Hudson, NP. Updated November 2008.