Syringomyelia (sear-IN-go-my-EEL-ya) is a disorder in which a cyst
forms within the spinal cord. This cyst, called a syrinx, expands and
elongates over time, destroying the center of the spinal cord. Since the
spinal cord connects the brain to nerves in the extremities, this damage
results in pain, weakness, and stiffness in the back, shoulders, arms, or
legs. Other symptoms may include headaches and a loss of the ability to
feel extremes of hot or cold, especially in the hands. Each patient
experiences a different combination of symptoms.
Other, more common disorders share the early symptoms of syringomyelia.
In the past, this has made diagnosis difficult. The advent of one
outpatient test, however, called magnetic resonance imaging (MRI), has
significantly increased the number of syringomyelia cases diagnosed in the
beginning stages of the disorder.
About 21,000 American men and women have syringomyelia, with symptoms
usually beginning in young adulthood. Signs of the disorder tend to
develop slowly, although sudden onset may occur with coughing or
straining. If not treated surgically, syringomyelia often leads to
progressive weakness in the arms and legs, loss of hand sensation, and
chronic, severe pain.
A watery, protective substance known as cerebrospinal fluid normally
flows around the spinal cord and brain, transporting nutrients and waste
products. It also serves to cushion the brain.
A number of medical conditions can cause an obstruction in the normal
flow of cerebrospinal fluid, redirecting it into the spinal cord itself.
For reasons that are only now becoming clear, this results in syrinx
formation. Cerebrospinal fluid fills the syrinx. Pressure differences
along the spine cause the fluid to move within the cyst. Physicians
believe that it is this continual movement of fluid that results in cyst
growth and further damage to the spinal cord.
Generally, there are two forms of syringomyelia. In most cases, the
disorder is related to an abnormality of the brain called a Chiari I
malformation, named after the physician who first characterized it. This
anatomic abnormality causes the lower part of the cerebellum to protrude
from its normal location in the back of the head into the cervical or neck
portion of the spinal canal. A syrinx may then develop in the cervical
region of the spinal cord. Because of the relationship that was once
thought to exist between the brain and spinal cord in this type of
syringomyelia, physicians sometimes refer to it as communicating
syringomyelia. Here, symptoms usually begin between the ages of 25 and 40
and may worsen with straining or any activity that causes cerebrospinal
fluid pressure to fluctuate suddenly. Some patients, however, may have
long periods of stability. Some patients with this form of the disorder
also have hydrocephalus, in which cerebrospinal fluid accumulates in the
skull, or a condition called arachnoiditis, in which a covering of the
spinal cord--the arachnoid membrane--is inflamed.
The second major form of syringomyelia occurs as a complication of
trauma, meningitis, hemorrhage, a tumor, or arachnoiditis. Here, the
syrinx or cyst develops in a segment of the spinal cord damaged by one of
these conditions. The syrinx then starts to expand. This is sometimes
referred to as noncommunicating syringomyelia. Symptoms may appear months
or even years after the initial injury, starting with pain, weakness, and
sensory impairment originating at the site of trauma.
The primary symptom of post-traumatic syringomyelia is pain, which may
spread upward from the site of injury. Symptoms, such as pain, numbness,
weakness, and disruption in temperature sensation, may be limited to one
side of the body. Syringomyelia can also adversely affect sweating, sexual
function, and, later, bladder and bowel control.
Some cases of syringomyelia are familial, although this is rare. In
addition, one form of the disorder involves a part of the brain called the
brainstem. The brainstem controls many of our vital functions, such as
respiration and heartbeat. When syrinxes affect the brainstem, the
condition is called syringobulbia.
Physicians now use magnetic resonance imaging (MRI) to diagnose
syringomyelia. The MR imager takes pictures of body structures, such as
the brain and spinal cord, in vivid detail. This test will show the syrinx
in the spine or any other conditions, such as the presence of a tumor. MRI
is safe, painless, and informative and has greatly improved the diagnosis
of syringomyelia.
The physician may order additional tests to help confirm the diagnosis.
One of these is called electromyography (EMG), which measures muscle
weakness. The doctor may also wish to test cerebrospinal fluid pressure
levels and to analyze the cerebrospinal fluid by performing a lumbar
puncture. In addition, computed tomography (CT) scans of a patient's head
may reveal the presence of tumors and other abnormalities such as
hydrocephalus.
Like MRI and CT scans, another test, called a myelogram, takes
x-ray-like pictures and requires a contrast medium or dye to do so. Since
the introduction of MRI this test is rarely necessary to diagnose
syringomyelia.
Surgery is usually recommended for syringomyelia patients. The main
goal of surgery is to provide more space for the cerebellum (Chiari
malformation) at the base of the skull and upper neck, without entering
the brain or spinal cord. This results in flattening or disappearance of
the primary cavity. If a tumor is causing syringomyelia, removal of the
tumor is the treatment of choice and almost always eliminates the syrinx.
Surgery results in stabilization or modest improvement in symptoms for
most patients. Delay in treatment may result in irreversible spinal cord
injury. Recurrence of syringomyelia after surgery may make additional
operations necessary; these may not be completely successful over the long
term.
In some patients it may be necessary to drain the syrinx, which can be
accomplished using a catheter, drainage tubes, and valves. This system is
also known as a shunt. Shunts are used in both the communicating and
noncommunicating forms of the disorder. First, the surgeon must locate the
syrinx. Then, the shunt is placed into it with the other end draining
cerebrospinal fluid into a cavity, usually the abdomen. This type of shunt
is called a ventriculoperitoneal shunt and is used in cases involving
hydrocephalus. By draining syrinx fluid, a shunt can arrest the
progression of symptoms and relieve pain, headache, and tightness. Without
correction, symptoms generally continue.
The decision to use a shunt requires extensive discussion between
doctor and patient, as this procedure carries with it the risk of injury
to the spinal cord, infection, blockage, or hemorrhage and may not
necessarily work for all patients.
In the case of trauma-related syringomyelia, the surgeon operates at
the level of the initial injury. The cyst collapses at surgery but a tube
or shunt is usually necessary to prevent re-expansion.
Drugs have no curative value as a treatment for syringomyelia.
Radiation is used rarely and is of little benefit except in the presence
of a tumor. In these cases, it can halt the extension of a cavity and may
help to alleviate pain.
In the absence of symptoms, syringomyelia is usually not treated. In
addition, a physician may recommend not treating the condition in patients
of advanced age or in cases where there is no progression of symptoms.
Whether treated or not, many patients will be told to avoid activities
that involve straining.
The precise causes of syringomyelia are still unknown. Scientists at
the National Institute of Neurological Disorders and Stroke in Bethesda,
Maryland, and at grantee institutions across the country continue to
explore the mechanisms that lead to the formation of syrinxes in the
spinal cord. For instance, Institute investigators have found that as the
heart beats, the syrinx fluid is abruptly forced downward. They have also
demonstrated the presence of a block to the free flow of cerebrospinal
fluid that normally occurs in and out of the head during each
heartbeat.
Surgical techniques are also being refined by the neurosurgical
research community. In one treatment approach currently being evaluated,
neurosurgeons perform a decompressive procedure where the dura mater, a
tough membrane covering the cerebellum and spinal cord, is enlarged with a
graft. Like altering a suit of clothing, this procedure expands the area
around the cerebellum and spinal cord, thus improving the flow of
cerebrospinal fluid and eliminating the syrinx.
It is also important to understand the role of birth defects in the
development of hindbrain malformations that can lead to syringomyelia.
Learning when these defects occur during the development of the fetus can
help us understand this and similar disorders, and may lead to preventive
treatment that can stop the formation of many birth abnormalities. Dietary
supplements of folic acid during pregnancy have already been found to
reduce the number of cases of certain birth defects.
Diagnostic technology is another area for continued research. Already,
MRI has enabled scientists to see conditions in the spine, including
syringomyelia, even before symptoms appear. A new technology, known as
dynamic MRI, allows investigators to view spinal fluid pulsating within
the syrinx. CT scans allow physicians to see abnormalities in the brain,
and other diagnostic tests have also improved greatly with the
availability of new, non-toxic, contrast dyes. Patients can expect even
better techniques to become available in the future from the research
efforts of scientists today.
Keeping on Top of Your Condition
Keeping in tune with your disease or condition not only makes treatment less intimidating but also increases its chance of success, and has been shown to lower a patients risk of complications. As well, as an informed patient, you are better able to discuss your condition and treatment options with your physician.
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BRAIN
P.O. Box 5801
Bethesda, Maryland 20824
(301)
496-5751
(800) 352-9424
http://www.ninds.nih.gov/
American Syringomyelia Alliance Project, Inc.
P.O. Box 1586
Longview, Texas 75606-1586
(903) 236-7079
1-800-ASAP-282
www.asap4sm.com/
*Several lay organizations are directly concerned with chronic pain.
They are excellent sources of additional information, research updates,
and specific help and referrals: National Chronic Pain Outreach
Association
7979 Old Georgetown Road
Suite 100
Bethesda,
Maryland 20814-2429
(301) 862-9437
American Chronic Pain Association
P.O. Box 850
Rocklin,
California 95677
(916) 632-0922
http://www.theacpa.org/
*The Chronic Pain Letter is a bimonthly review of new pain treatments,
books, and resources for people who live with pain. For subscription
information write:
Chronic Pain Letter
P.O. Box 1303
Old Chelsea Station
New
York, New York 10011
*The following national organizations are concerned with research,
care, and treatment of spinal cord injury and other paralyzing or
disabling conditions, and are sources of information, publications, and
advice:
Christopher Reeve Paralysis Foundation
500 Morris Avenue
Springfield, New Jersey 07081
(201) 379-2690
(800)
225-0292
http://www.paralysis.org/
National Spinal Cord Injury Association
545 Concord Avenue
Suite 29
Cambridge, Massachusetts 02138
(617) 441-8500
(800) 962-9629
http://www.spinalcord.org/
Paralyzed Veterans of America
National Office
801 18th Street,
NW
Washington, D.C. 20006
(202) 872-1300
http://www.pva.org/
Spinal Cord Society
Wendell Road
Fergus Falls, Minnesota 56537
(218) 739-5252
(218) 739-5262
members.aol.com/scsweb/
*Additional information about Arnold-Chiari malformation may be
available from:
Spina Bifida Association of America
4590 MacArthur Boulevard, NW
Suite 250
Washington, DC 20007
(202) 944-3285
(800)
621-3141
http://www.sbaa.org/
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, New York 10605
(914) 428-7100
(800) MODIMES
(663-4637)
http://www.modimes.org/
National Organization for Rare Disorders, Inc. (NORD)
55 Kenosia
Avenue
P.O. Box 1968
Danbury, CT 06813-1968
(203)
744-0100
(800) 999-6673 (voicemail only)
Fax: (203) 798-2291
http://www.rarediseases.org/
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