Minimal symptom expression is a term your doctor might use when you have no symptoms — or very mild symptoms — of myasthenia gravis (MG). MG is a chronic (long-term) condition that causes muscle weakness. If MG symptoms are not well controlled, they can significantly affect your quality of life. While there isn’t a permanent cure, MG treatments can help manage your symptoms.

Minimal symptom expression can be a goal you set with your doctor as part of your MG treatment. There isn’t one treatment that works for everyone with MG. Working with your doctor to establish your treatment goals is key to finding the best treatment plan for you.

What Are Treatment Goals?

Treatment goals are targets that you and your health care provider set to stay on the same page about the acceptable level of MG symptoms and treatment side effects. In general, the treatment goals for MG are to reduce your MG symptoms and improve your overall well-being and quality of life. However, your treatment goals can be more specific based on your personal needs and preferences.

It’s important to be open and honest with your MG specialist about what risks you’re comfortable with and what matters most to you. Your doctor may recommend different treatments based on your priorities.

Setting treatment goals also helps you and your MG specialist track how well a particular treatment is working for you. Over time, your goals may change. This is why it’s important to have regular conversations with your doctor about whether your current treatment plan is helping you achieve your goals.

How Are MG Symptoms Measured?

Minimal symptom expression (sometimes abbreviated as MSE) refers to having very mild or no symptoms of myasthenia gravis. It’s measured using the Myasthenia Gravis Activities of Daily Living scale (MG‐ADL).

The MG‐ADL evaluates eight MG symptoms on a scale of 0 to 3, from least to most severe. On this scale, a score of 0 means you don’t have any symptoms. A score of 3 means you have severe or constant symptoms The symptoms measured in the MG-ADL are weakness during the following activities:

• Talking
• Chewing
• Swallowing
• Breathing
• Brushing your teeth and combing your hair
• Standing from a seated position

The scale also measures two eye-related symptoms: double vision and eyelid droop.

What Score Is Considered Minimum Symptom Expression?

After evaluating your symptoms, your doctor will add up the scores for each symptom to find your total score. Minimal symptom expression is defined as an MG-ADL score of 0 to 1. Some studies have found that many people with MG feel “well enough” with an MG-ADL score of 2.

The MG-ADL can also be used to measure if you’ve gone into remission (no symptoms). Remission is defined as an MG-ADL score of 0.

Other Ways of Measuring MG Symptoms

There are several ways to measure how you’re responding to MG treatment. Most of these measurements are based on your response to a set of questions about your symptoms and how they impact your daily life.

International guidelines for MG treatment recommend aiming for minimal manifestation status (MMS) or better, with minimal side effects. MMS is defined as having no symptoms or functional limitations due to MG. However, some muscle weakness may still be detected during a physical exam. MMS is mainly assessed by your health care provider’s evaluation of your symptoms.

Other tools that may be used to assess MG symptoms include:

• MG Symptoms Patient-Reported Outcome (PRO) scale
• Patient Acceptable Symptom State (PASS)
• Myasthenia Gravis Impairment Index (MGII)

What Factors Go Into Choosing MG Treatment Options?

Several factors can influence which options for the treatment of myasthenia gravis may be best for you. Newer MG treatment options are helping more people with MG achieve minimal symptom expression. But all medications, even those sold over the counter, can cause side effects.

There are several factors to consider when choosing your MG treatment options. Your treatment goals can help guide you and your doctor in making the best decision.

MG Type and Severity

Your treatment will depend on the severity and type of your MG. For example, treatment for generalized myasthenia gravis (gMG) is different from treatment for ocular MG.

Blood tests that show specific MG-related autoantibodies (immune proteins) also play a role in treatment decisions. For example, rozanolixizumab-noli (Rystiggo) is approved for people with gMG who test positive for anti-acetylcholine receptor (AChR) or antimuscle-specific tyrosine kinase (MuSK) antibodies. However, zilucoplan (Zilbrysq) is approved only for people who are AChR antibody-positive. Even the decision to have a thymectomy (surgical removal of your thymus gland) depends on your antibody status.

Your doctor will also consider how severe your symptoms are and how well you respond to medications. For example, most people with MG will be treated with pyridostigmine (Mestinon) to control their symptoms. But if you have severe symptoms, or if pyridostigmine doesn’t work well enough, your health care provider may suggest other treatments.

Overall Health

Your overall health, including your age and any other health conditions, will also affect your treatment options.

Your age can affect how likely you are to experience side effects from certain medications. Older adults tend to have more severe side effects with pyridostigmine.

Other health conditions can also affect your treatment options. About 10 percent of people with MG also have a thymoma (a tumor in the thymus gland). If you have a thymoma, you may need additional treatments, such as a thymectomy, chemotherapy, or radiation therapy.

If you have another autoimmune disease, your MG specialist may suggest an immunosuppressive treatment that works for both conditions.

Diabetes is another medical condition that is common in people with MG. Diabetes affects how your body uses sugar, which can lead to high blood sugar levels. If you have diabetes, your MG specialist may recommend MG treatments that won’t worsen diabetes.

How a Treatment Is Taken

MG treatments can vary based on how often you need to take them and whether you take them at home or at your health care provider’s office.

Medications that help manage your symptoms, like pyridostigmine, must be taken multiple times per day. Other medications may only need to be taken once or twice a day, while some infusions for MG are given weekly.

Some treatments, like prednisone and other immunosuppressant drugs, come in pill form and can be taken at home. Other medications are available as injections you give subcutaneously (under the skin). Most people can learn how to give themselves these injections at home.

Other treatments can only be given at a health care provider’s office or a hospital, such as intravenous (IV) infusions, which are given directly into the vein. These are given weekly or monthly.

Be sure to talk to your MG specialist about your preferences for how you want to receive your MG treatment.

Treatment Effectiveness

How well and how quickly a medication works is a key factor in choosing a treatment. Clinical trials help researchers measure how effective a medication is. Many clinical trials for new MG treatments measure how many people achieve minimal symptom expression. Your MG specialist can guide you in choosing the treatments most likely to work for you.

Treatment Side Effects

Not everyone who takes a medication will experience every potential side effect. Still, it’s important to understand the possible side effects and how long they tend to last. Side effects (also known as adverse events) can make it hard to stick to your treatment plan.

For instance, pyridostigmine can cause stomach-related side effects that some people find hard to tolerate.

Long-term use of corticosteroids may lead to weight gain, diabetes, stomach ulcers, and mood changes.

Newer MG treatments, such as eculizumab (Soliris), ravulizumab (Ultomiris), and efgartigimod (Vygart and Vigart Hytrulo), can also cause bothersome side effects. Common side effects of these medications may include headaches, diarrhea, and an increased risk of infection.

Even if your MG treatment is working well to control your symptoms, medication side effects can also affect your quality of life your quality of life. Make sure your neurology team knows about any new or worsening symptoms, especially if they’re making it harder to stick to your treatment plan.

What Makes It Harder To Reach Your MG Treatment Goals?

If you’re not reaching your MG treatment goals, such as achieving minimum symptom expression, it’s important to talk to your MG specialist. They can help identify any barriers to progress. Some common challenges to reaching your MG treatment goals include treatment side effects and how convenient your treatment is.

Switching treatments can also be difficult. It may take time to see how a new treatment will work, and it can be hard to predict how the treatment will affect you. If you’ve found ways of coping with your symptoms or side effects, trying an unknown treatment can be scary. Additionally, stopping some treatments (such as corticosteroids or steroids) can temporarily make you feel worse.

Talk With Others Who Understand

MGteam is the social network where people with myasthenia gravis and their loved ones come together to ask questions, give advice, and share their stories with others who understand life with myasthenia gravis.

What are your MG treatment goals? How often do you and your MG specialist discuss your treatment goals? Share your experience in the comments below, or start a conversation by posting on your Activities page.