A DISEASE CALLED MYASTHENIA GRAVIS

     Most of the serious medical illnesses that healthcare professionals treat can be grouped into diseases where cells grow uncontrollably such as cancers or attributed to diseases where blood vessels get stopped up such as heart attacks or strokes.  Together, these two problems account for more than half of all deaths that occur in the United States.  People get tired of being hammered on about don’t do this or don’t do that so that you could avoid having a heart attack, stroke or cancer.  So someone asked about an obscure disease called myasthenia gravis.

     There are a large number of illnesses over which the person has absolutely no control to prevent the condition. These are diseases that “just happen”.  The person with some diseases didn’t do a thing to either let the disease happen or make it happen.  Myasthenia gravis is one these.

     The disease usually begins slowly and over the course of several weeks or several months, the person finds that their muscular strength fails.  The condition very often begins with the muscles around the eyes and patients with myasthenia gravis virtually “can’t keep their eyes open.”  As the day goes on, the muscles of the face become weak and the eyes tend to drift shut.  If the person has to grip a knife to peel potatoes or use a hammer to drive nails, their limbs virtually become so weak that they cannot continue.  This is not related to getting short of breath or having overall fatigue, rather it is the muscles being used that fatigue and fail.  After a period of rest, the person can continue again but they fatigue very quickly when they return to their activity.  These patients frequently seek medical attention with a concern that they are “weak and tired.”  This is a very nonspecific complaint that infrequently leads to a medical diagnosis.  The true cause of the problem is very difficult to diagnose and the person often struggles with the symptoms for weeks or even months before the correct diagnosis is made.

     Myasthenia is a medical work made up of two parts.  The first part “my-“ relates to muscle and the second part of the word, “-asthenia” means weakness.  So myasthenia is a fancy medical word for saying the person’s muscles are weak.  The word “gravis” refers to the seriousness of the problem.  So myasthenia gravis is the name given to a condition in which the  person has some serious muscle weakness.  It doesn’t mean tired at the end of a long days work.  It means that you can’t drive the 4th nail into a board or peel the 3rd potato for the evening meal.

     To understand the cause of this disease, think of any electric appliance in your home that you have to plug in.  The professor that first taught me about this condition made the analogy to his mother’s steam iron that she used to press his shirts. This is probably not a good example because now we have wrinkle-free shirts and nobody uses steam irons anymore but 50 years ago we did.  Mom would plug the steam iron in, it would get warm, and make steam which then pressed the shirt beautifully.  Imagine what would happen if the plug-in just didn’t work.  There is nothing wrong with the iron.  There is nothing wrong with the wall socket but where the cord plugs into the iron, the electricity just doesn’t go by.  The iron never gets hot.  The same problem exists in a person with myasthenia gravis.  Their muscles work just fine.  Normally, there is a nerve that goes to the muscle that makes the muscle contract (work).  This nerve carries electricity to the muscle to tell the muscle to contract but there is a disruption at the point where the nerve attaches to the muscle.  The message from the nerve telling the muscle to contract just doesn’t get there and the more the person tries, the worse the problem seems to get.

     As strange at it may seem, the biological problem involves the person becoming allergic to the connection between their nerves and their muscles.  Most people have heard of being allergic to Penicillin or peanuts but can’t begin to understand how you can become allergic to your muscle motor endplate but that is exactly what happens.  Untreated, the disease would frequently become fatal over months to a few years and the person would die because their breathing muscles quit working.

     Fortunately in today’s world there are a number of treatments available for this condition.  Just as we can prevent a person from rejecting a kidney transplant, the same principles can be applied to keep the person from rejecting their motor end plates on their muscles.  Myasthenia gravis can usually be effectively treated although medications have to be taken on a regular basis for a long time.

     In summary, myasthenia gravis is a rare disease that happens for no known reason.  The person becomes allergic to their own motor end plates where the nerve attaches to a muscle.  This allergy prevents the muscle from getting the message and the person becomes very weak with repetitive efforts.  Fortunately, there are effective treatments and the person can lead a relatively normal life with medical help.