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| What
is syringomyelia?
(sear-IN-go-my-EEL-ya)
Syringomyelia, often referred to as SM, is a chronic disorder involving
the spinal cord. For reasons that are only now being understood,
cerebrospinal fluid enters the spinal cord, forming a cavity known as a
syrinx. (Doctors sometimes use other words such as cyst, hydromyelia or
syringohydromyelia) This syrinx often expands and elongates over time,
destroying the center of the spinal cord. As the nerve fibers inside
the spinal cord are damaged, a wide variety of symptoms can occur,
depending upon the size and location of the syrinx.
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(Click on the image to enlarge) |
There
are two major types of SM. In most cases it is related to a congenital
malformation involving the hindbrain (cerebellum) called a Chiari I
Malformation, named after the physician who first described it. This
malformation occurs during fetal development and is characterized by
downward displacement of the lower part of the brain (cerebellar
tonsils) beneath the foramen magnum, into the cervical spinal canal.
This displacement blocks the normal flow of cerebrospinal fluid. When
normal flow is obstructed, a syrinx can then form in the spinal
cord.
Not all
patients with Chiari Malformations will develop a syrinx,
however. SM can also occur as a complication of trauma, meningitis, tumor,
arachnoiditis, or a tethered spinal cord. In these cases the syrinx
forms in the section of the spinal cord damaged by these conditions. As
more people are surviving spinal cord injuries, more cases of
post-traumatic SM are being diagnosed as the syrinx can form years
after the trauma. |
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What are the symptoms?
The symptoms of SM are numerous and a person may have various
combinations of different symptoms. Symptoms tend to develop slowly,
although sudden onset may occur with coughing and straining. Some
common symptoms include: loss of sensitivity, especially to hot and
cold, muscle weakness and spasticity, motor impairment, loss of bowel
and bladder control, as well as osteoporosis and scoliosis. The
majority of patients suffer from headaches and chronic pain.
Although Syringomyelia was first described over 400 years ago, very
little research was performed and as a result little was known about
the disorder. Only recently, with the advent of MRI and the dramatic
rise in diagnosed cases, have significant advancements been made. In
the past, SM was considered a disorder that always resulted in slow,
progressive degeneration. Researchers now believe it is possible that
some patients may never progress.
What should be done?
The first step after diagnosis is finding a neurosurgeon who is
experienced in the treatment of SM. Finding a specialist is highly
recommended. Surgery is the only viable treatment for SM, but not all
patients will advance to the stage where surgery is needed. Evaluation
of the condition is often difficult because SM can remain stationary
for long periods of time, and in some cases progress rapidly.
Treatment is aimed at correcting the condition that allowed the syrinx
to form, if possible. In cases involving a Chiari Malformation, the
main goal of surgery is to provide more space for the cerebellum at the
base of the skull and upper cervical spine. This often results in a
flattening or disappearance of the syrinx as the normal flow of
cerebrospinal fluid is restored. In some cases it may be necessary to
insert a shunt into the cavity, rerouting the cerebrospinal fluid from
the spinal cord. A successful surgery will stabilize the condition and
perhaps gain a modest improvement in symptoms, but over time surgery is
not always successful and multiple surgeries may be necessary.
Since the natural history of SM is poorly understood, a conservative
approach may be recommended. When surgery is not yet advised, patients
should be carefully monitored by a neurologist or neurosurgeon.
Periodic MRI's and physical evaluations should be scheduled at the
recommendation of a qualified physician.
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