September 23, 2026 • 13 mins
What happens when your immune system attacks the point of communication between your nerves and muscles? That's an autoimmune condition called myasthenia gravis, and it leads to muscle weakness that starts around the eyes and can progress to the face, neck, and limbs. Learn about its symptoms, what causes them, and how different treatments can help relieve them in today's episode of BrainStuff.
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Speaker 1 (00:01):
Welcome to BrainStuff, a production of iHeartRadio. Hey BrainStuff, Lauren
Vogelbaum here. For many of us, a lot of purposeful
motions feel automatic. Our gait when we walk, our posture
when we sit, a smile when a friend enters the room.
Some can even feel compulsive. Like, have you ever known
(00:25):
or been an emphatic gesticulator? I've accidentally smacked people during
excited conversations. But all of our purposeful motions are actually
the result of an incredibly complex chain of electrochemical actions
in our bodies, from our nervous system to our muscles
and back again, that tell us from experience that we're
(00:46):
on steady ground to take our next step, or that
we're sitting up straight, or that our smile is warm
and welcoming, or that we've just flailed into someone and
need to apologize. It takes a lot of things in
our bodies going right just to blink. So what happens
when something goes wrong? Today, let's look at a condition
(01:07):
called myasthenia gravis. In myasthenia gravis, the communication between your
nerves and your muscles breaks down, resulting in muscle weakness
and easy fatigue in areas like the eyes, face, neck,
and limbs, making it difficult to control your vision and expressions,
to move around, and sometimes even to swallow or breathe.
(01:31):
The term comes from ancient Greek words for muscle and weakness,
along with the Latin for severe or grave. It was
coined in the late 1800s. Physicians have been describing these
types of muscle fatigue since the 1600s, but it wasn't
until around the 1960s that we began understanding what we
were looking at. It turns out that myasthenia gravis is
(01:53):
an autoimmune condition. We've talked before on the show about
how the immune system works and what can go wonky
when it isn't working as expected. It's meant to clear
out dead or damaged cells and fight off germs and
remember how to fight them again in the future. But
for reasons we don't understand very well, sometimes your immune
(02:15):
system makes a mistake and attacks healthy cells in your body.
In arthritis, it attacks your joints. In psoriasis, it can
attack your skin. In myasthenia gravis, your immune system attacks
the points of communication between your nerves and muscles. It's
sort of like in a horror flick or thriller, where
(02:36):
the bad guy cuts the phone line or power line
going to a house, leaving the heroes in the dark,
literally or figuratively. The signal, or electricity, may still be
coming through the wire, but it can't be received. It's
a little more complicated in our bodies because we are
electrochemically driven meat. We'll have to do a whole episode
(02:57):
on how your nerves tell your muscles to do stuff,
and we will. But very basically, our muscle fibers are
all connected to our nervous system via tiny junctions with
motor neurons. When we want to, say, blink, nerve impulses
travel to the motor neurons in our eyelids. Our muscles
(03:18):
can't receive the signal directly. Our motor neurons have to
translate or transform the signal into something that the muscles
can get. So the motor neurons give off chemicals that
transmit the neural signal, aka neurotransmitters. Okay, so the junction
in question here is a tiny gap between the motor
(03:41):
neuron and the muscle fibers that it's communicating with. To
pass along the signal, the motor neuron releases neurotransmitters into
that gap. They'll be caught by receptors on the surface
of the muscle fibers, which, again, very basically, can then
recognize that a request for movement has been made and
can trigger muscle contraction. So, you blink. This can happen
(04:06):
very quickly. Now, in vertebrates like humans, the main neurotransmitter
involved in muscle stimulation is called acetylcholine. In the condition
Myasthenia gravis, your immune system attacks your acetylcholine receptors on
your muscle fibers. Or, in some cases, the immune system
(04:26):
also or instead attacks other proteins that are involved with
maintaining these neuromuscular junctions. This effectively causes the same breakdown
in communication. But, okay, why? Good question. Let's talk about
the immune response. When your immune system is working normally,
(04:47):
it's constantly scanning for invaders, you know, viruses, bacteria, and
other things that might pose a threat. It does this
by looking for identifying molecules called antigens on the surface
of germs and your cells and anything else that it
comes across. If the thing in question is from your
own body and thus belongs there, your immune system should
(05:11):
recognize that. But If your immune system identifies those antigens
as being not from your body, and therefore potentially unsafe,
it will launch an attack. It attacks by developing invader-specific
proteins called antibodies that can destroy the antigen and anything
attached to it, or tag it for destruction by immune
(05:33):
system cells. After the battle, your immune system will stockpile
that antibody, and remember how to identify that antigen. in
most cases, forever. So if your immune system encounters antigens
of the same type later on, it can fight the
disease off fast. This immune response is really great when
(05:54):
it comes to chickenpox, or the variant of the flu
going around this year. It means that you won't get
chickenpox again, and that you might be able to take
a vaccine to teach your immune system about this flu
variant and thus avoid getting sick from it. But sometimes, Again,
for reasons we don't really understand, your immune system misidentifies
(06:16):
some of your own cells as a threat and produces
antibodies to attack them. In myasthenia gravis, your immune system
creates antibodies that stuff up, block, damage, or otherwise impair
the function of those acetylcholine receptors on your muscle fibers. So,
Your motor neurons are releasing the neurotransmitter that should tell
(06:39):
the muscle fibers in your eyes to, for example, blink,
but the muscle fibers can't receive the signal. It's not
exactly like the line is cut, more like the signal
is coming through real patchy. In our thriller metaphor, it's
like if the bad guy is jamming the frequency. Because
all of this doesn't mean that your muscles will never work.
(07:00):
but they can become less reliable or stop responding after
periods of activity. I picked blinking as an example here
because myasthenia gravis often first presents as muscle weakness around
the eyes. You might notice one or both of your
eyelids drooping, have difficulty moving your eyes, or experience blurriness
(07:21):
or double vision because your eyes are basically out of
sync If symptoms don't progress beyond the eye muscles, that's
called ocular myasthenia gravis. It affects around 10% of people
with the condition. More commonly, you'll start to notice muscle
weakness around the rest of the face and neck and
down into the limbs. This is called generalized myasthenia gravis.
(07:45):
It can make you feel very fatigued. It can become
difficult to stand up or lift objects, and you might
tire quickly or get wobbly when walking. Your hands might
feel clumsy. Depending on exactly what muscles are affected, your
speech might sound different, softer or more nasal or garbled.
Your face might be less expressive. Chewing and swallowing can
(08:08):
become a chore, and you might even find yourself choking easily.
In some cases, the respiratory muscles become weak too, and
you might experience shortness of breath. That symptom in particular
can be life-threatening if your muscles tire out and you
can't get enough air. This is called a myasthenic crisis,
and about a fifth of people with the condition will
(08:30):
experience it at least once. Definitely tell your healthcare provider
about any shortness of breath that you or a loved
one experienced so that you can monitor the situation, and
always get emergency care if you're struggling to breathe. All
of this can be scary, and to Even if it's
not physically scary, it can be really frustrating to feel
(08:51):
out of control of your movement, expressions, and stamina. The
muscle weakness experienced is typically made worse by activity and
better by rest. There's unfortunately no cure for myasthenia gravis yet,
but there are lots of treatment options to help manage symptoms.
The first step is diagnosis. Anyone can develop myasthenia gravis,
(09:15):
though it most commonly first appears in adult women ages
30 to 50 and adult men over the age of 60.
It doesn't usually run in families, but does pop up
more often in people who already have an autoimmune disorder.
A healthcare provider will talk through your symptoms, give you
a physical exam to see how your muscles are behaving
or misbehaving, and may perform one or a few tests.
(09:38):
A blood test can look for telltale antibodies that your
immune system has produced that are misguidedly built to attack
those acetylcholine receptors or the proteins that help neuromuscular junctions work.
An electrical activity test can be used to measure your muscles'
responses to signals from nerves, and they might have you
undergo some kind of imaging scan. like an MRI or
(10:01):
CT scan, to check out your thymus. The thymus is
an immune system gland in your chest where some of
your specialized attack cells, called T-cells, mature. The thymus is
usually active during our childhoods and then phases out as
we get older. If something unusual is going on with it,
that can be a solid sign of an autoimmune disorder.
(10:24):
Once you've got a diagnosis, you can look at what
treatments might be most helpful for you. Your healthcare provider
might talk to you about different medications, including immunosuppressants, that is,
drugs like steroids that can suppress an overactive immune system,
or what's called acetylcholine esterase inhibitors. These help prevent the
breakdown of acetylcholine in your body, leaving you with more
(10:47):
of it for your muscle fibers to receive. So the
medication basically boosts the signals from your motor neurons. Both
of these types of medications might be taken by mouth
or injection. There are also a few types of infusions
that may be prescribed. Donor antibodies can help remove or
replace harmful antibodies in your system. There's also a class
(11:11):
of treatments called monoclonal antibodies, which are antibodies produced in
labs to target something specific and bind to it, thus
accomplishing something. It's a clever concept because you can basically
build a monoclonal antibody to target anything in our bodies.
There are a few different ones used in myasthenia gravis
that target different cells or proteins that are involved in
(11:34):
the immune response that's preventing communication from your motor neurons
to your muscle fibers. In cases where there is something
weird with the thymus gland, like maybe there's a tumor there,
surgery to remove the gland might be recommended. Of course,
there's also a lot you can do at home to
help boost muscle strength and alleviate some of that fatigue.
(11:56):
People often feel fresher in the morning and tire as
the day goes on. Work with that instead of against it,
and take on more difficult tasks when you feel up
for it. Make sure to avoid overheating, which can make
symptoms worse. Take breaks or naps as you need to
help restore some function. Be sure to get enough protein
(12:17):
and carbs in your diet to fuel you. And regular exercise,
though it may wear you out in the immediate moment,
can help strengthen your muscles and give you more energy
down the line. It really can help improve your mood,
which is earnestly very annoying, but true. Your healthcare provider
might recommend physical therapy and or a support group to
(12:39):
help you figure out what works best. The symptoms of
myasthenia gravis can be more or less severe. They can
change by the day, week, or month. They can even
go into remission for months or for years. Again, there
is no cure, but with treatment, most people lead full
and active lives. New research is improving our understanding of
(13:01):
the condition all the time and leading to more effective treatments.
But hey, I'm just a podcaster. If you or a
loved one has been experiencing symptoms of muscle weakness, talk
to a health care provider about it. And take care
of yourself, okay? Today's episode was written by me, Lauren Vogelbaum.
(13:25):
BrainStuff is a production of iHeart Podcasts and is produced
by Tyler Klang. For more shows from iHeart Podcasts, visit
the iHeart Radio app, Apple Podcasts, or wherever you listen
to your favorite shows.
Welcome to BrainStuff, a production of iHeartRadio. Hey BrainStuff, Lauren
Vogelbaum here. For many of us, a lot of purposeful
motions feel automatic. Our gait when we walk, our posture
when we sit, a smile when a friend enters the room.
Some can even feel compulsive. Like, have you ever known
(00:25):
or been an emphatic gesticulator? I've accidentally smacked people during
excited conversations. But all of our purposeful motions are actually
the result of an incredibly complex chain of electrochemical actions
in our bodies, from our nervous system to our muscles
and back again, that tell us from experience that we're
(00:46):
on steady ground to take our next step, or that
we're sitting up straight, or that our smile is warm
and welcoming, or that we've just flailed into someone and
need to apologize. It takes a lot of things in
our bodies going right just to blink. So what happens
when something goes wrong? Today, let's look at a condition
(01:07):
called myasthenia gravis. In myasthenia gravis, the communication between your
nerves and your muscles breaks down, resulting in muscle weakness
and easy fatigue in areas like the eyes, face, neck,
and limbs, making it difficult to control your vision and expressions,
to move around, and sometimes even to swallow or breathe.
(01:31):
The term comes from ancient Greek words for muscle and weakness,
along with the Latin for severe or grave. It was
coined in the late 1800s. Physicians have been describing these
types of muscle fatigue since the 1600s, but it wasn't
until around the 1960s that we began understanding what we
were looking at. It turns out that myasthenia gravis is
(01:53):
an autoimmune condition. We've talked before on the show about
how the immune system works and what can go wonky
when it isn't working as expected. It's meant to clear
out dead or damaged cells and fight off germs and
remember how to fight them again in the future. But
for reasons we don't understand very well, sometimes your immune
(02:15):
system makes a mistake and attacks healthy cells in your body.
In arthritis, it attacks your joints. In psoriasis, it can
attack your skin. In myasthenia gravis, your immune system attacks
the points of communication between your nerves and muscles. It's
sort of like in a horror flick or thriller, where
(02:36):
the bad guy cuts the phone line or power line
going to a house, leaving the heroes in the dark,
literally or figuratively. The signal, or electricity, may still be
coming through the wire, but it can't be received. It's
a little more complicated in our bodies because we are
electrochemically driven meat. We'll have to do a whole episode
(02:57):
on how your nerves tell your muscles to do stuff,
and we will. But very basically, our muscle fibers are
all connected to our nervous system via tiny junctions with
motor neurons. When we want to, say, blink, nerve impulses
travel to the motor neurons in our eyelids. Our muscles
(03:18):
can't receive the signal directly. Our motor neurons have to
translate or transform the signal into something that the muscles
can get. So the motor neurons give off chemicals that
transmit the neural signal, aka neurotransmitters. Okay, so the junction
in question here is a tiny gap between the motor
(03:41):
neuron and the muscle fibers that it's communicating with. To
pass along the signal, the motor neuron releases neurotransmitters into
that gap. They'll be caught by receptors on the surface
of the muscle fibers, which, again, very basically, can then
recognize that a request for movement has been made and
can trigger muscle contraction. So, you blink. This can happen
(04:06):
very quickly. Now, in vertebrates like humans, the main neurotransmitter
involved in muscle stimulation is called acetylcholine. In the condition
Myasthenia gravis, your immune system attacks your acetylcholine receptors on
your muscle fibers. Or, in some cases, the immune system
(04:26):
also or instead attacks other proteins that are involved with
maintaining these neuromuscular junctions. This effectively causes the same breakdown
in communication. But, okay, why? Good question. Let's talk about
the immune response. When your immune system is working normally,
(04:47):
it's constantly scanning for invaders, you know, viruses, bacteria, and
other things that might pose a threat. It does this
by looking for identifying molecules called antigens on the surface
of germs and your cells and anything else that it
comes across. If the thing in question is from your
own body and thus belongs there, your immune system should
(05:11):
recognize that. But If your immune system identifies those antigens
as being not from your body, and therefore potentially unsafe,
it will launch an attack. It attacks by developing invader-specific
proteins called antibodies that can destroy the antigen and anything
attached to it, or tag it for destruction by immune
(05:33):
system cells. After the battle, your immune system will stockpile
that antibody, and remember how to identify that antigen. in
most cases, forever. So if your immune system encounters antigens
of the same type later on, it can fight the
disease off fast. This immune response is really great when
(05:54):
it comes to chickenpox, or the variant of the flu
going around this year. It means that you won't get
chickenpox again, and that you might be able to take
a vaccine to teach your immune system about this flu
variant and thus avoid getting sick from it. But sometimes, Again,
for reasons we don't really understand, your immune system misidentifies
(06:16):
some of your own cells as a threat and produces
antibodies to attack them. In myasthenia gravis, your immune system
creates antibodies that stuff up, block, damage, or otherwise impair
the function of those acetylcholine receptors on your muscle fibers. So,
Your motor neurons are releasing the neurotransmitter that should tell
(06:39):
the muscle fibers in your eyes to, for example, blink,
but the muscle fibers can't receive the signal. It's not
exactly like the line is cut, more like the signal
is coming through real patchy. In our thriller metaphor, it's
like if the bad guy is jamming the frequency. Because
all of this doesn't mean that your muscles will never work.
(07:00):
but they can become less reliable or stop responding after
periods of activity. I picked blinking as an example here
because myasthenia gravis often first presents as muscle weakness around
the eyes. You might notice one or both of your
eyelids drooping, have difficulty moving your eyes, or experience blurriness
(07:21):
or double vision because your eyes are basically out of
sync If symptoms don't progress beyond the eye muscles, that's
called ocular myasthenia gravis. It affects around 10% of people
with the condition. More commonly, you'll start to notice muscle
weakness around the rest of the face and neck and
down into the limbs. This is called generalized myasthenia gravis.
(07:45):
It can make you feel very fatigued. It can become
difficult to stand up or lift objects, and you might
tire quickly or get wobbly when walking. Your hands might
feel clumsy. Depending on exactly what muscles are affected, your
speech might sound different, softer or more nasal or garbled.
Your face might be less expressive. Chewing and swallowing can
(08:08):
become a chore, and you might even find yourself choking easily.
In some cases, the respiratory muscles become weak too, and
you might experience shortness of breath. That symptom in particular
can be life-threatening if your muscles tire out and you
can't get enough air. This is called a myasthenic crisis,
and about a fifth of people with the condition will
(08:30):
experience it at least once. Definitely tell your healthcare provider
about any shortness of breath that you or a loved
one experienced so that you can monitor the situation, and
always get emergency care if you're struggling to breathe. All
of this can be scary, and to Even if it's
not physically scary, it can be really frustrating to feel
(08:51):
out of control of your movement, expressions, and stamina. The
muscle weakness experienced is typically made worse by activity and
better by rest. There's unfortunately no cure for myasthenia gravis yet,
but there are lots of treatment options to help manage symptoms.
The first step is diagnosis. Anyone can develop myasthenia gravis,
(09:15):
though it most commonly first appears in adult women ages
30 to 50 and adult men over the age of 60.
It doesn't usually run in families, but does pop up
more often in people who already have an autoimmune disorder.
A healthcare provider will talk through your symptoms, give you
a physical exam to see how your muscles are behaving
or misbehaving, and may perform one or a few tests.
(09:38):
A blood test can look for telltale antibodies that your
immune system has produced that are misguidedly built to attack
those acetylcholine receptors or the proteins that help neuromuscular junctions work.
An electrical activity test can be used to measure your muscles'
responses to signals from nerves, and they might have you
undergo some kind of imaging scan. like an MRI or
(10:01):
CT scan, to check out your thymus. The thymus is
an immune system gland in your chest where some of
your specialized attack cells, called T-cells, mature. The thymus is
usually active during our childhoods and then phases out as
we get older. If something unusual is going on with it,
that can be a solid sign of an autoimmune disorder.
(10:24):
Once you've got a diagnosis, you can look at what
treatments might be most helpful for you. Your healthcare provider
might talk to you about different medications, including immunosuppressants, that is,
drugs like steroids that can suppress an overactive immune system,
or what's called acetylcholine esterase inhibitors. These help prevent the
breakdown of acetylcholine in your body, leaving you with more
(10:47):
of it for your muscle fibers to receive. So the
medication basically boosts the signals from your motor neurons. Both
of these types of medications might be taken by mouth
or injection. There are also a few types of infusions
that may be prescribed. Donor antibodies can help remove or
replace harmful antibodies in your system. There's also a class
(11:11):
of treatments called monoclonal antibodies, which are antibodies produced in
labs to target something specific and bind to it, thus
accomplishing something. It's a clever concept because you can basically
build a monoclonal antibody to target anything in our bodies.
There are a few different ones used in myasthenia gravis
that target different cells or proteins that are involved in
(11:34):
the immune response that's preventing communication from your motor neurons
to your muscle fibers. In cases where there is something
weird with the thymus gland, like maybe there's a tumor there,
surgery to remove the gland might be recommended. Of course,
there's also a lot you can do at home to
help boost muscle strength and alleviate some of that fatigue.
(11:56):
People often feel fresher in the morning and tire as
the day goes on. Work with that instead of against it,
and take on more difficult tasks when you feel up
for it. Make sure to avoid overheating, which can make
symptoms worse. Take breaks or naps as you need to
help restore some function. Be sure to get enough protein
(12:17):
and carbs in your diet to fuel you. And regular exercise,
though it may wear you out in the immediate moment,
can help strengthen your muscles and give you more energy
down the line. It really can help improve your mood,
which is earnestly very annoying, but true. Your healthcare provider
might recommend physical therapy and or a support group to
(12:39):
help you figure out what works best. The symptoms of
myasthenia gravis can be more or less severe. They can
change by the day, week, or month. They can even
go into remission for months or for years. Again, there
is no cure, but with treatment, most people lead full
and active lives. New research is improving our understanding of
(13:01):
the condition all the time and leading to more effective treatments.
But hey, I'm just a podcaster. If you or a
loved one has been experiencing symptoms of muscle weakness, talk
to a health care provider about it. And take care
of yourself, okay? Today's episode was written by me, Lauren Vogelbaum.
(13:25):
BrainStuff is a production of iHeart Podcasts and is produced
by Tyler Klang. For more shows from iHeart Podcasts, visit
the iHeart Radio app, Apple Podcasts, or wherever you listen
to your favorite shows.
BrainStuff News
Host
Lauren Vogelbaum
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