Guillain-Barre syndrome (ghee-yan bah-ray) is a disorder in which the
body's immune system attacks part of the peripheral nervous system. The
first symptoms of this disorder include varying degrees of weakness or
tingling sensations in the legs. In many instances the weakness and
abnormal sensations spread to the arms and upper body. These symptoms can
increase in intensity until certain muscles cannot be used at all and,
when severe, the patient is almost totally paralyzed. In these cases the
disorder is life threatening – potentially interfering with breathing and,
at times, with blood pressure or heart rate – and is considered a medical
emergency. Such a patient is often put on a respirator to assist with
breathing and is watched closely for problems such as an abnormal heart
beat, infections, blood clots, and high or low blood pressure. Most
patients, however, recover from even the most severe cases of
Guillain-Barre syndrome, although some continue to have a certain degree
of weakness.
Guillain-Barre syndrome can affect anybody. It can strike at any age
and both sexes are equally prone to the disorder. The syndrome is rare,
however, afflicting only about one person in 100,000. Usually
Guillain-Barre occurs a few days or weeks after the patient has had
symptoms of a respiratory or gastrointestinal viral infection.
Occasionally surgery or vaccinations will trigger the syndrome. The
disorder can develop over the course of hours or days, or it may take up
to 3 to 4 weeks. Most people reach the stage of greatest weakness within
the first 2 weeks after symptoms appear, and by the third week of the
illness 90 percent of all patients are at their weakest.
No one yet knows why Guillain-Barre syndrome strikes some people and not others.
Nor does anyone know exactly what sets the disease in motion.
What scientists do know is that the body's immune system begins to
attack the body itself, causing what is known as an autoimmune disease.
Usually the cells of the immune system attack only foreign material and
invading organisms. In Guillain-Barre syndrome, however, the immune system
starts to destroy the myelin sheath that surrounds the axons of many
peripheral nerves, or even the axons themselves (axons are long, thin
extensions of the nerve cells; they carry nerve signals). The myelin
sheath surrounding the axon speeds up the transmission of nerve signals
and allows the transmission of signals over long distances.
In diseases in which the peripheral nerves' myelin sheaths are injured
or degraded, the nerves cannot transmit signals efficiently. That is why
the muscles begin to lose their ability to respond to the brain's
commands, commands that must be carried through the nerve network. The
brain also receives fewer sensory signals from the rest of the body,
resulting in an inability to feel textures, heat, pain, and other
sensations. Alternately, the brain may receive inappropriate signals that
result in tingling, "crawling-skin," or painful sensations. Because the
signals to and from the arms and legs must travel the longest distances
they are most vulnerable to interruption. Therefore, muscle weakness and
tingling sensations usually first appear in the hands and feet and
progress upwards.
When Guillain-Barre is preceded by a viral or bacterial infection, it
is possible that the virus has changed the nature of cells in the nervous
system so that the immune system treats them as foreign cells. It is also
possible that the virus makes the immune system itself less discriminating
about what cells it recognizes as its own, allowing some of the immune
cells, such as certain kinds of lymphocytes and macrophages, to attack the
myelin. Sensitized T lymphocytes cooperate with B lymphocytes to produce
antibodies against components of the myelin sheath and may contribute to
destruction of the myelin. Scientists are investigating these and other
possibilities to find why the immune system goes awry in Guillain-Barre
syndrome and other autoimmune diseases. The cause and course of
Guillain-Barre syndrome is an active area of neurological investigation,
incorporating the cooperative efforts of neurological scientists,
immunologists, and virologists.
Guillain-Barre is called a syndrome rather than a disease because it is
not clear that a specific disease-causing agent is involved. A syndrome is
a medical condition characterized by a collection of symptoms (what the
patient feels) and signs (what a doctor can observe or measure). The signs
and symptoms of the syndrome can be quite varied, so doctors may, on rare
occasions, find it difficult to diagnose Guillain-Barre in its earliest
stages.
Several disorders have symptoms similar to those found in
Guillain-Barre , so doctors examine and question patients carefully before
making a diagnosis. Collectively, the signs and symptoms form a certain
pattern that helps doctors differentiate Guillain-Barre from other
disorders. For example, physicians will note whether the symptoms appear
on both sides of the body (most common in Guillain-Barre ) and the
quickness with which the symptoms appear (in other disorders, muscle
weakness may progress over months rather than days or weeks). In
Guillain-Barre , reflexes such as knee jerks are usually lost. Because the
signals traveling along the nerve are slower, a nerve conduction velocity
(NCV) test can give a doctor clues to aid the diagnosis. In Guillain-Barre
patients, the cerebrospinal fluid that bathes the spinal cord and brain
contains more protein than usual. Therefore a physician may decide to
perform a spinal tap, a procedure in which the doctor inserts a needle
into the patient's lower back to draw cerebrospinal fluid from the spinal
column.
There is no known cure for Guillain-Barre syndrome. However, there are
therapies that lessen the severity of the illness and accelerate the
recovery in most patients. There are also a number of ways to treat the
complications of the disease.
Currently, plasmapheresis and high-dose immunoglobulin therapy are
used. Both of them are equally effective, but immunoglobulin is easier to
administer. Plasmapheresis is a method by which whole blood is removed
from the body and processed so that the red and white blood cells are
separated from the plasma, or liquid portion of the blood. The blood cells
are then returned to the patient without the plasma, which the body
quickly replaces. Scientists still don't know exactly why plasmapheresis
works, but the technique seems to reduce the severity and duration of the
Guillain-Barre episode. This may be because the plasma portion of the
blood contains elements of the immune system that may be toxic to the
myelin.
In high-dose immunoglobulin therapy, doctors give intravenous
injections of the proteins that, in small quantities, the immune system
uses naturally to attack invading organisms. Investigators have found that
giving high doses of these immunoglobulins, derived from a pool of
thousands of normal donors, to Guillain-Barre patients can lessen the
immune attack on the nervous system. Investigators don't know why or how
this works, although several hypotheses have been proposed.
The use of steroid hormones has also been tried as a way to reduce the
severity of Guillain-Barre , but controlled clinical trials have
demonstrated that this treatment not only is not effective but may even
have a deleterious effect on the disease.
The most critical part of the treatment for this syndrome consists of
keeping the patient's body functioning during recovery of the nervous
system. This can sometimes require placing the patient on a respirator, a
heart monitor, or other machines that assist body function. The need for
this sophisticated machinery is one reason why Guillain-Barre syndrome
patients are usually treated in hospitals, often in an intensive care
ward. In the hospital, doctors can also look for and treat the many
problems that can afflict any paralyzed patient – complications such as
pneumonia or bed sores.
Often, even before recovery begins, caregivers may be instructed to
manually move the patient's limbs to help keep the muscles flexible and
strong. Later, as the patient begins to recover limb control, physical
therapy begins. Carefully planned clinical trials of new and experimental
therapies are the key to improving the treatment of patients with
Guillain-Barre syndrome. Such clinical trials begin with the research of
basic and clinical scientists who, working with clinicians, identify new
approaches to treating patients with the disease.
Guillain-Barre syndrome can be a devastating disorder because of its
sudden and unexpected onset. In addition, recovery is not necessarily
quick. As noted above, patients usually reach the point of greatest
weakness or paralysis days or weeks after the first symptoms occur.
Symptoms then stabilize at this level for a period of days, weeks, or,
sometimes, months. The recovery period may be as little as a few weeks or
as long as a few years. About 30 percent of those with Guillain-Barre
still have a residual weakness after 3 years. About 3 percent may suffer a
relapse of muscle weakness and tingling sensations many years after the
initial attack.
Guillain-Barre syndrome patients face not only physical difficulties,
but emotionally painful periods as well. It is often extremely difficult
for patients to adjust to sudden paralysis and dependence on others for
help with routine daily activities. Patients sometimes need psychological
counseling to help them adapt.
Scientists are concentrating on finding new treatments and refining
existing ones. Scientists are also looking at the workings of the immune
system to find which cells are responsible for beginning and carrying out
the attack on the nervous system. The fact that so many cases of
Guillain-Barre begin after a viral or bacterial infection suggests that
certain characteristics of some viruses and bacteria may activate the
immune system inappropriately. Investigators are searching for those
characteristics. Certain proteins or peptides in viruses and bacteria may
be the same as those found in myelin, and the generation of antibodies to
neutralize the invading viruses or bacteria could trigger the attack on
the myelin sheath. As noted previously, neurological scientists,
immunologists, virologists, and pharmacologists are all working
collaboratively to learn how to prevent this disorder and to make better
therapies available when it strikes.
Keeping on Top of Your Condition
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BRAIN
P.O. Box 5801
Bethesda, Maryland 20824
(301)
496-5751
(800) 352-9424
Guillain-Barre Syndrome Foundation International
P.O. Box 262
Wynnewood, PA 19096
(610) 667-0131
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