gravis (MG) is a neuromuscular disorder that causes weakness in the skeletal
muscles, which are the muscles your body uses for movement. It occurs when
communication between nerve cells and muscles becomes impaired. This impairment
prevents crucial muscle contractions from occurring, resulting in muscle
weakness. According to the Myasthenia Gravis Foundation of
is the most common primary disorder of neuromuscular transmission. It’s a
relatively rare condition that affects between 14 and 20 out of every 100,000
people in the United States.
What Are the Symptoms of
symptom of MG is weakness in the voluntary skeletal muscles, which are muscles
under your control. The failure of muscles to contract normally occurs because
they can’t respond to nerve impulses. Without proper transmission of the
impulse, a blocked communication occurs between nerve and muscle and weakness
associated with MG typically gets worse with more activity and improves with
rest. Symptoms of MG can include:
- trouble talking
- problems walking up stairs or
- facial paralysis
- difficulty breathing because of
- difficulty swallowing or chewing
- hoarse voice
- drooping of eyelids
- double vision
will have every symptom, and the degree of muscle weakness can change from day
to day. The severity of the symptoms typically increases over time if left
What Causes Myasthenia
MG is a
neuromuscular disorder that’s usually caused by an autoimmune problem. Autoimmune
disorders occur when your immune system mistakenly attacks healthy tissue. In
this condition, antibodies, which are proteins that normally attack foreign,
harmful substances in the body, attack the neurotransmitter substance
acetylcholine, which is a crucial substance for communication between nerve
cells and muscles. This results in muscle weakness.
cause of this autoimmune reaction is unclear to scientists. According to the Muscular Dystrophy Association, one theory is that certain
viral or bacterial proteins may prompt the body to attack acetylcholine.
the National Institutes of Health, MG typically occurs in people over the age
of 40. Women are more likely to be diagnosed as younger adults, whereas men are
more likely to be diagnosed at 60 or older.
How Is Myasthenia Gravis
will perform a complete physical exam, as well as take a detailed history of your
symptoms. They’ll also do a neurological exam. This may consist of:
- checking your reflexes
- looking for muscle weakness
- checking for muscle tone
- making certain your eyes move
- testing sensation in different
areas of your body
- testing motor functions, like
touching your finger to your nose
that can help your doctor diagnose the condition include:
- repetitive nerve stimulation test
- blood testing for antibodies
associated with MG
- edrophonium (Tensilon) test: A
drug called Tensilon (or a placebo) is administered intravenously, through a vein,
and you’re asked to perform muscle movements under doctor observation
- imaging of the chest, using CT scans
or MRI, to rule out a tumor
Treatment Options for
There is no
cure for MG. The goal of treatment is to manage symptoms and control the
activity of your immune system.
and immunosuppressants can be used to suppress the immune system. These
medications help minimize the abnormal immune response that occurs in MG.
cholinesterase inhibitors, such as pyridostigmine (Mestinon), can be used to
increase communication between nerves and muscles.
Thymus Gland Removal
the thymus gland, which is part of the immune system, may be appropriate for many
patients with MG. Once the thymus is removed, patients typically show less
the Myasthenia Gravis Foundation of
between 10 and 15 percent of people with MG will have a tumor in their thymus. Tumors,
even those that are benign, are always removed because they may become
is also known as a plasma exchange. This process removes harmful antibodies
from the blood, which may result in an improvement in muscle strength.
is a short-term treatment. The body continues to produce the harmful antibodies
and weakness may recur. Plasma exchange is helpful before surgery or during
times of extreme MG weakness.
Intravenous Immune Globulin
immune globulin (IVIG) is blood product that comes from donors. It’s used to
treat autoimmune MG. Although it’s not entirely known how IVIG works, it
affects the creation and function of antibodies.
some things you can do at home to help alleviate symptoms of MG:
- Get plenty of rest to help
minimize muscle weakness.
- If you’re bothered by double
vision, talk to your doctor about whether you should wear an eye patch.
- Avoid stress and heat exposure,
as both can worsen symptoms.
treatments cannot cure MG. However, you’ll typically see improvements in your symptoms.
Some individuals may go into remission, during which treatment is not
doctor about any medications or supplements you take. Some drugs can make MG
symptoms worse. Before taking any new medication, check with your doctor to
ensure it’s safe.
Complications of Myasthenia
One of the
most dangerous potential complications of MG is myasthenic crisis. This consists of life-threatening muscle
weakness that can include breathing problems. Talk with your doctor about your
risks. If you start to have trouble breathing or swallowing, call 911 or go to
your local emergency room immediately.
with MG are at a higher risk of developing other autoimmune disorders such as lupus and rheumatoid arthritis.
long-term outlook for MG depends on a lot of factors. Some people will only
have mild symptoms. Others may eventually become confined to a wheelchair. Talk
to your doctor about what you can do to minimize the severity of your MG. Early
and proper treatment can limit disease progression in many people.