Health Uncomplicated: Myasthenia Gravis Symptoms, Diagnosis and Treatments
What is Myasthenia Gravis?
Myasthenia Gravis is a rare chronic autoimmune neuromuscular condition that causes weakness in skeletal muscles. Approximately 14-40 per 100,000 individuals in the United States have a diagnosis of Myasthenia Gravis. (1)
Myasthenia Gravis affects the body’s skeletal muscles which are the muscles that connect to the bones. Skeletal muscles produce movement by contracting when they respond to stimuli. They sustain body posture and position, maintain body temperature, store nutrients, and stabilize joints. (2)
What are the Symptoms of Myasthenia Gravis?
The hallmark symptoms of Myasthenia Gravis include muscle weakness that worsens after activity and improves after periods of rest. A classic presentation of Myasthenia Gravis can be a fluctuating weakness that is present in the afternoon. The muscles that are primarily affected include muscles that control:
eyes and eyelid movement
facial expressions
chewing
talking
swallowing
Because these muscles are impacted, they can translate into symptoms that can include:
Weakness of eye muscles (ocular myasthenia)
Drooping of one or both eyelids (ptosis)
Blurred or double vision (diplopia)
Changes in facial expressions
Difficulty swallowing
Shortness of breath
Impaired speech (dysarthria)
Weakness in arms, hands, fingers, legs, neck
Weakness (when severe, can lead to respiratory failure and require immediate emergency care)
What does the onset of Myasthenia Gravis look like?
The onset of Myasthenia Gravis symptoms may be sudden, and symptoms may not originally be recognized as Myasthenia Gravis. Additionally, the degree of muscle weakness experienced varies between individuals. (3)
Myasthenia Gravis affects both males and females of all ethnic groups. Females who have Myasthenia Gravis are most likely to experience an onset of symptoms before age 40, and men who have the condition are primarily over the age of 60. However, Myasthenia Gravis can affect individuals at any point in their lives, including childhood, although this is less common. (4)
How do I get Diagnosed with Myasthenia Gravis?
There are a few tests that can be performed to diagnose Myasthenia Gravis. (5)
Physical and Neurological Examination.
This examination for Myasthenia Gravis checks:
Muscle strength and tone
Coordination
Sense of touch and sight
Impairment of eye movements
Balance
Reflexes
Ice pack Test
If you are experiencing droopy eyelid(s), a provider might put a bag of ice on this eyelid. After two minutes, they will remove the bag, and analyze the eyelid for movement.
Blood test and analysis
A blood test might show non typical antibodies that interrupt the binding of acetylcholine to the receptor site.
Repetitive nerve stimulation
Electrodes are attached to skin over the muscles. Then, small pulses of electricity run through the electrodes. The pulses measure whether the nerve can send a signal to the muscle. The nerve is tested multiple times to see if the signal gets worse with fatigue. This test helps to inform the diagnosis.
Single Fiber Electromyography (EMG)
This measures electrical activity that travels between the brain and muscles. This activity is measured by inserting a fine wire electrode through the skin into a muscle to test a single muscle fiber.
Imaging
CT or MRI is performed to check the Thymus for any abnormalities or tumors
What are the treatments available for Myasthenia Gravis?
Thymectomy
The thymus gland is removed via surgery. This can reduce symptoms by rebalancing the immune system.
A study of 126 people, both with thymoma and without thymoma (tumors of the Thymus gland), was performed. In this study, each individual underwent a Thymectomy. This surgery reduced muscle weakness and a need for immunosuppressive drugs. The goal of this surgery is stable, long lasting, and complete remission, and occurs in about 50% of individuals who undergo this procedure. (6)
Monoclonal antibody
This treatment targets the process of acetylcholine antibodies attacking the neuromuscular junction.
FDA approved the use of Eculizumab for general Myasthenia Gravis in adults with a positive anti-acetylcholine receptor antibody. (7)
Cholinesterase Inhibitors
These medications slow the breakdown of acetylcholine at the neuromuscular junction and improve the transmission of acetylcholine from the neuron to the muscle. This increases muscle strength. (8)
Mestinon and Pyridostigmine fall under this category.
Immunosuppressants
This class of drugs improves muscle strength by suppressing the production of abnormal antibodies
Prednisone, Azathioprine, Mycophenolate Mofetil, and Tacrolimus are commonly prescribed immunosuppressants.
Plasmapheresis and Intravenous Immunoglobulin (IVIG)
In severe cases of Myasthenia Gravis, patients are given Plasmapheresis or IVIG to remove the destructive antibodies that attack the neuromuscular junction. The effectiveness of this treatment lasts anywhere from weeks to months.
What is Plasmapheresis?
Plasmapheresis is when the plasma with the destructive antibodies is removed and replaced with healthy plasma or plasma substitute.
What is Intravenous Immunoglobulin (IVIG)?
IVIG is a highly concentrated injection of antibodies that are pooled from many healthy donors. When injected, it temporarily changes the way the immune system operates.
What tools are available for managing Myasthenia Gravis observations from symptom onset, to diagnosis, to treatment?
Tracking your observations on the Folia app. You can note anything that happens, add appointments, and create graphs and reports to bring to your provider. Our newest Flare Tracking feature can be helpful for noting when symptoms worsen. Link to download here, use code FOLIA4MG at registration!
You may find it helpful to track weakness of eye muscles in one or both eyes (ocular myasthenia), drooping of one or both eyelids (ptosis), blurred or double vision (diplopia), changes in facial expressions, difficulty swallowing, shortness of breath, impaired speech (dysarthria), and/or weakness in arms, hands, fingers, legs and neck
Folia Forms. These printable forms are helpful for sorting out thoughts before, during, and after appointments. Then, simply put this information into your app or add a picture of the page to your Folia profile so all info lives in the same place. You can access Forms here.
Additional comments or questions? The Folia Team is here to help!