Transcript myasthenia gravis

MYASTHENIA
GRAVIS
“FROM WEAKNESS SHALL
COME STRENGTH”.
BY PATTI HAMILTON
Myasthenia Gravis –
definition – from greek and latin
means “grave muscle weakness”.
Who gets MG?
All ethnic groups
Most commonly young women
(under 40) and older men (
over 60), but it can occur at
any age.
It is not inherited nor is it
contagious.
Famous people include – David
Niven, Aristotle Onassis, Sir
Lawrence Olivier, Phil silvers,
and Sleepy .
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Sleepy was
supposedly based on
a friend of Walt
Disney who had MG.
What is Myasthenia Gravis?
Chronic autoimmune neuromuscular
disease.
 Characterized by varying degrees of
weakness of the voluntary muscles of the
body.
 Hallmark sign is muscle weakness that
increases with activity and improves after
periods of rest.
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What causes Myasthenia Gravis?
What causes MG?
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A defect in the transmission of nerve impulses to muscles at
neuromuscular junction.
Antibodies block, alter, or destroy the receptors for acetylcholine at
the NMJ which prevents the muscle from contracting.
Studies show that patients with Mg have only about one third as
many acetylcholine receptors at the NMJ as is normal.
Signs and symptoms
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In most cases, the 1st noticeable symptom is weakness of eye
muscles. In other cases, difficulty swallowing and slurred speech
may be the first sign.
Other Symptoms include and vary in type and severity, they are
ptosis, diplopia, unstable and waddling gait, weakness in arms,
hand, fingers, legs, neck, a change in facial expression, and
shortness of breath.
The vocal cords can become weak and the voice is nasal sounding.
As the disease progresses, the patient will have trouble with
walking, sustained sitting, and raising their arms over their heads.
Breathing problems can become so severe they require a ventilator.
Bowel and bladder sphincter weakness occurs.
Diagnostics
The simplest diagnostic test is to have the
patient look up for 2 to 3 minutes. The
patient with MG will barely be able to keep
their eyes open.
 Electromyogram
 Serum testing for antibodies
 Edrophonium test.
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How is Myasthenia Gravis treated?
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Medications include – Anticholinesterase agents
which include neostigmine and pyridostigmine.
Immunosuppressive drugs such as
cyclophosphamide, cyclosporine, and
azathioprine. Care must be taken with
medications because many classes of drugs are
contraindicated with patients with MG. These
include anesthetics, antidysrhythmics,
antibiotics, quinine, antipsychotics, barbiturates,
sedatives, hypnotics, opioids, tranquilizers, and
thyroid preparations.
Treatment Continued 
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Plasmapheresis
Thymectomy – In adults with MG the thymus
gland is abnormal. Some individuals develop
thymomas which require surgical removal. (
Thymectomy reduces symptoms in more than
70% of patients without thymoma and cures
some individuals).
High dose intravenous immune globulin.
Myasthenic crisis
A myasthenic crises occurs when the
muscles that control breathing weaken to
the point that ventilation is inadequate.
This is a medical emergency and requires
a respirator for assisted ventilation.
 A crisis may be triggered by infection,
fever, or an adverse reaction to
medication.
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Nursing interventions 
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Airway protective techniques – Chin tuck, double
swallowing.
Suctioning if necessary, for upper respiratory
infections.
Medications 1 hr. before meals.
Feeding tube if swallowing is a problem.
Assess need for respiratory assistance with
Serial determination of vital capacity, minute
volumes, and tidal volumes.
Patient teaching
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Take meds. As prescribed times and to take
them early enough before eating or activities to
obtain maximum relief.
Explain how to adjust medication dose to
maintain muscle strength.
Medications to avoid.
Seek medical attention at first sign of URI.
Eat only when sitting up to prevent aspiration.
Teaching Continued
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Avoid crowds in flu and cold season.
Explain how to adjust daily activities to allow for
leisure activities and rest periods.
To use minimal energy in ADL’s so that energy
may be used for activities that patient enjoys.
Advise patient to wear medic-alert bracelet.
What is the prognosis?
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With Treatment, the outlook for most patients is
bright. They will have significant improvement of
their muscle weakness and they can expect to
lead normal or nearly normal lives.
Some patients may go into remission
temporarily, so that medications can be
discontinued.
In a few cases, a severe crisis (respiratory
failure) may cause death.