an image of a woman taking her glasses off has been distorted, elongated, blurred, and swirled - culminating in an image that is quite foggy, paralleling her brain fog

Myasthenia Gravis and Brain Fog

Myasthenia gravis (MG) is an autoimmune disease that affects the muscles of the body. The immune system creates antibodies that fight the neuromuscular junction. This is the area where a nerve sends signals to a muscle to control its movements.

These antibodies affect some muscles more than others. Muscles in the eyes, face, and throat are often affected. Your arms and legs may also be affected.1

Common MG symptoms include drooping eyelids, difficulty chewing or swallowing, and muscle weakness in the arms or legs. Fatigue is also a common symptom.1

The fatigue of MG can affect more than just the body. It can affect your mood and your thoughts. Some living with MG describe this as difficulty “thinking straight or making decisions.” It may feel like it takes more effort to get things done. This brain fog is very common. It is caused by a combination of factors.2

What causes brain fog?

Brain fog seems to be a side effect of other MG symptoms rather than a symptom itself. This means that the antibodies that are common in MG do not directly affect the brain.

However, symptoms like fatigue, low oxygen during sleep, and poor sleep may work together to cause brain fog.3

The antibodies in MG can affect the muscles used to breathe. During the day, the body can make up for that weakness by using other muscles in the neck and stomach to help us take deep breaths.

But that does not happen during sleep. Because of this, some people living with MG may have lower oxygen levels at night from shallow breathing. Low oxygen levels can make you feel sleepy or foggy during the day. 4

Difficulty sleeping

Some people living with MG report difficulty sleeping. These difficulties include insomnia, restless leg syndrome (RLS), and side effects from certain MG drugs. Active MG symptoms can also have an effect on how much rest you need.

When your muscles are weak, it takes more energy to accomplish daily tasks. You also may need to use other muscles to compensate. This all can result in poor sleep and not enough sleep, resulting in brain fog.2

How does MG affect thinking?

Some researchers have studied the way that MG affects thinking. Unfortunately, these studies were small. Some of the information gleaned from those studies about what kinds of thinking are affected contradicts the results of other studies.

However, the research agreed on certain things. Those living with MG had lower scores on tests of memory and verbal learning compared to a group of people without MG. However, both groups scored high on tests of attention.5

It is not clear how much of an effect this may have on those living with MG. However, it may explain some of the brain fog.5

What can I do?

Unfortunately, MG drugs cannot directly improve brain fog. There are things that you can do to help though! Sleep hygiene is an important first step.

Waking up and going to sleep at a consistent time can help your body fall into a rhythm. Avoiding bright lights and screen time before bed can also help your brain slow down to prepare for sleep.

If you are experiencing sleep issues like RLS or if improving your sleep hygiene does not help, speak to your doctor. They may be able to prescribe drugs or send you to a specialist to help improve your sleep.2

Planning ahead

If fatigue and brain fog are something that you struggle with, it may help to plan, pace, and prioritize. Plan important things during the time of day that you have the most energy.

For example, if you have the most energy in the morning, it may help to plan appointments in the morning so that you can rest in the evening.

Pace yourself when it comes to the tasks that take the most energy. Space out chores and responsibilities so that you can rest and regain energy in-between.

Finally, prioritize by taking care of your most important tasks first. Less important tasks can be done once you have more energy and focus. If you can, delegate tasks to friends and family.2

Be kind to yourself. Rest is important to your well-being and quality of life. If you have questions about brain fog and MG symptoms, speak to your doctor.

By providing your email address, you are agreeing to our privacy policy. We never sell or share your email address.


Join the conversation

or create an account to comment.