Cervical Spine
February, 2006
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 (C1-C7 vertebrae),
which are separated from one another by intervertebral discs. These
discs allow the spine to move freely and act as shock absorbers during
activity.
Attached to the back of each vertebral body is an arch of bone
that forms a continuous hollow longitudinal 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 (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
You may have been referred to a neurosurgeon because of pain in
your neck or shoulder, or tingling and numbness in your arms. You may
also have experienced some weakness in your arms or hands.
Neck pain may be caused by disc degeneration, narrowing of the
spinal canal, arthritis, and, in rare cases, cancer or meningitis. For
serious neck problems, a primary care physician and often a specialist,
such as a neurosurgeon, should be consulted to make an accurate
diagnosis and prescribe treatment.
You should consult a neurosurgeon for neck pain if:
- 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, causing disc
herniation or bone spurs to form. Sudden severe injury to the neck may
also contribute 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 region can be a very
serious problem because 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 potentially compromise the
function of many important organs.
Cervical stenosis
Cervical stenosis occurs when the spinal canal narrows and
compresses the spinal cord and 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 that compress the
nerve roots. Mild stenosis can be treated conservatively for extended
periods of time 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 by a neurosurgeon 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 includes 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. 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 can be
utilized, the choice of which is influenced by the severity of your
case. In a small percentage of patients, spinal instability may require
that spinal fusion be performed, 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 Disectomy
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 intervertebral 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 in conjunction with the anterior
cervical disectomy. 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 distracted 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, as with any surgery, 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 percentage of cervical spine
patients report significant pain relief after surgery, there is no
guarantee that surgery will help every individual.
Postsurgery
Your doctor will give you specific instructions postsurgery and
usually prescribe pain medication. Your doctor will 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.