JARGON BUSTER
INFORMATION ABOUT MG & ASSOCIATED ACRONYMS
This list of information was compiled to explain in
layman?s terms, some of the names and acronyms
used for various treatments and diagnostic tools used in the treatment and
diagnosis of our illness. It can be so confusing if you are new to MG and
people start using terminology like ?IVIG?,
hopefully this list will go some way to simplifying these terms If you require a
more complete description, please consult your physician.
MYASTHENIA GRAVIS
Myasthenia Gravis is derived from two words one Greek and
the other Latin.
Myasthenia comes from the
Greek and means ?muscle weakness?
Gravis comes from the
Latin and means ?severe?
IVIG
IntraVenous
ImmunoGlobulin
- this is a treatment used to treat MG as well as some other auto-immune
diseases. It involves transfusing Immunoglobulins which is a component of blood
that carries ?healthy? antibodies taken from donors and protects the recipient
and boosts his/her immune system. The exact effect is not fully understood, but
it is believed it also reduces the production of auto-antibodies which attack
the host such as patients with MG.
PLASMA PHERESIS
Plasma Pheresis also known
as Plasma Exchange, is carried out using a
machine which looks not dissimilar to a dialysis machine. Blood is removed via
one cannula (tube) and the ?clean? blood is returned via another cannula. The
machine processes the blood using a centrifugal pump, which separates the
components of the blood and the plasma, which
contains the auto-antibodies (bad guys) is removed and replaced by a mixture of
human albumen (another component of blood) and saline solution. In most cases
the treatment is given by the use of cannula inserted on the day, but when
patients have ?poor? veins or the patient is in Myasthenic Crisis, this may
require the insertion of a Central Line for the course of the treatment and
requires a minor surgical procedure.
CELLCEPT
Cellcept also known as
Mycophenolate mofetil is a drug used originally as an Immuno-suppressant
after transplant surgery. Tests are being carried out for its use as a form of
treatment for MG and to date, the results have been favourable. It was chosen
as a test drug, because it is believed to have fewer side effects than some of
the drugs in current use and allows the reduction of these drugs and sometimes
replaces them completely.
TENSILON TEST
The ?Tensilon? test is sometimes used as a tool for
diagnosing MG. In severe symptoms the effect can be extremely dramatic, with
the patient ?recovering? from all the symptoms drooping eyes, difficulty
breathing, swallowing difficulties, etc. Unfortunately the symptoms return
within a few minutes after the test. The drug used in this test is called
Edrophonium chloride and is injected into the patient. This procedure is
normally done in a hospital environment due to possible risks. In ?milder?
cases the result might not be so obvious and the test can sometimes be
considered as a ?failure?, this does NOT mean that you DO NOT have MG, just that
the test was inconclusive, subsequent tests can prove positive.
NEURO or NEURO OPTHO.
List members often refer to their ?Neuro?s? this is simply
an abbreviation for Neurologist or Neuro surgeon. Neuro-Opth is also used and
is an abbreviation Neurological Ophthalmologist (no wonder they shorten it)
SERO NEG
Blood tests are taken to confirm the presence of AChR (Acetycholine
receptor) antibodies which cause the MG and in most cases (approximately 80%)
this an effective way of determining that the patient is Myasthenic. However it
has been known that some patients (20%) with MG do NOT have the antibodies to
AChR?s and instead make antibodies to another muscle target which has now been
identified thanks to the research work carried out at Oxford in the UK by
Professor Angela Vincent and her team. This protein is known as MuSK and a
different test (which has been developed) is required. The people having this
second type of antibody to the MuSK protein, are referred to as
SERO NEG. This
is a new development and effectively means that with testing now available for
AChR antibodies and MuSK antibodies, this gives blanket coverage for all
Myasthenics.
MESTINON-PREDNISONE-IMURAN also known as AZATHIOPRINE
The treatment for MG/OMG is normally approached on
TWO fronts
-
By
increasing the availability of Acetycholine at the
Neuro Muscular Joint
(NMJ)
to maximise the chances of the signal from the nerve reaching the muscle. A
balance must be struck, too much can have the same effect as too little and
make matters worse. The doctors strive to achieve what is known as
MRL maximum
response level (the same is true of the other drugs used). The drug used for
this purpose is Pyridostigmine bromide better known as
MESTINON to
MG?ers.
-
By reducing the production of the auto-antibodies
which attack the NMJ. For this the drugs PREDNISONE and or IMURAN (azathioprine)
are used. These drugs are known as IMMUNO-SUPPRESSANTS
i.e. they suppress the immune system. Prednisone is a hormone also known as a
?corticosteroid? (which occurs naturally in the body) although when taken in
pill form, the dose is at least 20 times more than the body would naturally
produce. To reduce the side effects of this drug, the dosage is taken EVERY
OTHER DAY (EOD)
or it is used in conjunction with
IMURAN
to allow the dosage of the
PREDNISONE to
be reduced.
EMG TEST
Another tool used in the diagnosis of MG is called
?electromyography? better known as
EMG. In one test the muscle response to
electrical stimulation of the nerve is recorded. In a patient with MG the
response gets smaller over the first few stimuli. There is a similar test,
which is slightly more refined and is known as the
SINGLE FIBRE EMG. The responses of individual muscle fibres are
studied. Both these tests involve a lot of scary scientific equipment, but the
tests themselves are more uncomfortable than painful but you do feel like a
guinea pig in an experiment, surrounded by oscilloscopes, electrodes and
probes. Don?t worry it looks a lot worse than it actually is.
CAT SCAN OR CT SCAN
Conventional X-ray techniques have one major flaw, they are
two dimensional and overlying organs or tissue can obscure the target site. If
you are for example looking for a brain tumour, surrounding brain tissue blocks
the view. To overcome this, a new form of X-ray machine was developed formerly
called a CAT or now known as a
CT Scan. CAT
means Computerised Axial Tomography and CT
stands for Computed Tomography. In this process the patient is placed
inside an X-ray machine, and a narrow beam of X-rays sweeps across an area of
the body, moving through a slight angle after each X-ray pulse. The resulting
series of X-ray images, taken from a different angle, is recorded electronically
and analysed by a computer. From them, the computer produces a three
dimensional X-ray image.
CT (computed tomography),
or CAT (computerised axial tomography) scanners
are specialised X-ray cameras that take highly detailed images of hard and soft
tissues. By picturing one layer of the body?s tissues at a time.
CT scanners can detect very small tumours and
other disorders.
MRI SCAN
Nuclear magnetic resonance or Magnetic
Resonance Imaging,
is a hazard free, non invasive method that uses radio waves in the presence of a
strong magnetic field to probe a patient and generate visual images of thin
slices of the brain, heart, liver and other organs. The high contrast,
variable-toned images that result can uncover tumours, blood starved tissues and
plaques. In the procedure termed scintigraphy, a small amount of radioactive
isotope is introduced into the body. A scintiscan camera, or gamma camera,
measure the uptake and concentration of the isotope in certain tissues, such as
the brain, kidney, or thymus gland.
Metabolic diseases and other disorders can be uncovered by this technique.
PLEASE NOTE! Both
CT scans and MRI
scans do NOT detect the presence of MG, they are merely tools used in
diagnostics. The CT scan eliminates ?other?
possibilities for the symptoms we suffer, and the MRI scan is used to check on
the condition of the Thymus gland.
THYMECTOMY
A thymectomy is a surgical procedure in which the chest is
opened to remove the Thymus gland. The Thymus gland is responsible from an
early age in developing our immune system. There are two main reasons for
carrying out this procedure.
a)
The Thymus gland is found to be abnormal, usually brought about by a
tumour (known as a thymoma) which if left to grow, can cause problems with
surrounding tissues in the chest cavity. This tumour, it should be noted, is in
a very large majority of patients ?benign? (not cancerous)
b)
Surgeons will in some cases consider a thymectomy in young or adolescent
myasthenics as beneficial to treat MG, particularly the child patients. This
procedure is carried out in adults up to the age of about 45 years of age after
which it is regarded as less effective.
The topic of thymectomies causes a lot of controversy among
Myasthenics and doctors alike. I do not intend to advocate or otherwise the
efficacy of this procedure, it is best left to the individual and their own
physician.
ICE TEST
This is a very simple test used to check on the Ptosis
(droopy eye lids) of an MG patient. An ice cube or cold compress containing ice
is held against the eyelids of the patient for two to three minutes. In a
patient with MG, the ptosis (droopy eyelids) will improve and the amount the
eyelids can be opened will increase. This test only works on patients with MG
and is regarded as another tool in diagnosis as well as having some therapeutic
value.
PRISMS OR FRESNEL LENSES
In a lot of cases, the myasthenic having difficulty
focusing can have ?prisms? (also known as fresnel lenses) prescribed. These can
either be ground in to your present eye glass lenses or the more popular ?stick
on? type are also available. Some MG?ers swear by these lenses, while others
don?t find them as beneficial. It?s basically a question of what suits you as
an individual
SURGICAL TAPE (CLAVIN TAPE)
In severe cases of Ptosis (droopy eyelids) the use of
porous surgical tape to hold up the eyelids is often used. Although the taped
eyelids may look rather strange, the ability to see, makes it very worthwhile
and if you wear a pair of sun glasses when going out, this makes it look a lot
less obvious. Props to hold up the eyelids are also available in some cases,
these attach to the glasses and help hold the eyelids open.
MEDICAL TERMINOLOGY
Doctors and other medical staff use terminology which most
of us as patients find difficult to understand. I am listing just a few of
those which you might find useful if you hear them mentioned in your vicinity.
PTOSIS
Medical term for what we as MG?ers call Droopy eye lids
DYSPHAGIA
This is the medical term for when you have difficulty
swallowing.
DISARTHIA
This indicates you have slurred or fatiguing speech
DISPHONIC
Your voice sounds strange.
LARYNGEAL
Connected with the voice
PHARANGEAL
Relating to the throat.
Some of these sound scary until you realise what they mean.
Osserman
Classification in Myasthenia Gravis
Many doctors classify your stage of myasthenia using the
Osserman Classification system and we include a breakdown of the system used to
help clarify these definitions.
The first useful clinical classification system
was developed by Osserman and thereafter modified.
0 Asymptomatic
1 Ocular signs and symptoms
2 Mild generalized weakness
3 Moderate generalized weakness, bulbar
dysfunction, or both
4 Severe generalized weakness,
respiratory dysfunction, or both
or
Stage
Symptoms
Neonatal Transient symptoms from
myasthenic mother
Juvenile
Adult group I Localized, usually ocular only
Adult group II Acute fulminating, bulbar and
generalized with respiratory failure
Adult group IV Late severe, evolving from
groups I and II
Adult group V With muscle atrophy, evolving
from group II.
? Brian Houston 2002-2006
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