Myasthenia Gravis

Myasthenia gravis is a condition that weakens muscles you use to move. It happens because the signals from your nerves to your muscles aren't working properly. This makes the muscles feel weak and tire out easily.

Unfortunately, there's no way to completely get rid of myasthenia gravis. However, treatments can help manage the symptoms. These symptoms can manifest in various ways, including weakness in your arms or legs, blurry or double vision, drooping eyelids, and trouble with speaking, chewing, swallowing, and breathing.

Myasthenia gravis can impact people of any age. However, it's more frequently diagnosed in women under 40 and men over 60.

Myasthenia gravis is a condition that causes muscle weakness. This weakness gets worse after using the affected muscles. Because rest often improves the weakness, symptoms can come and go. However, the symptoms generally get progressively worse over time, usually reaching their worst within a few years of the disease starting.

Myasthenia gravis can affect any muscle you control, but some are more commonly affected than others. In over half of people with the condition, the first signs appear in the eyes. These signs include:

• Drooping eyelids (ptosis): One or both eyelids might droop.
• Double vision (diplopia): You might see double, and this usually gets better or goes away when you close one eye.

In about 15% of cases, the first symptoms involve the muscles of the face and throat. These symptoms can:

• Make talking difficult: Your voice might sound soft, weak, or have a nasal quality.
• Cause swallowing problems: You might choke easily, making eating, drinking, or taking pills challenging. Food or liquid might come out your nose when swallowing.
• Affect chewing: Your chewing muscles might tire quickly, especially if you're eating something tough like steak.
• Change facial expressions: Your smile might look strained or unnatural.

Myasthenia gravis can also cause weakness in the neck, arms, and legs. Leg weakness can affect your gait (how you walk). Weak neck muscles can make it hard to hold your head up.

It's crucial to talk to your doctor if you experience any of these problems:

• Breathing difficulties
• Vision problems
• Swallowing problems
• Chewing problems
• Walking problems
• Weakness in your arms or hands
• Trouble holding your head up

If you notice any of these symptoms, it's important to seek medical attention. Early diagnosis and treatment can help manage the condition and improve quality of life.

If you're having trouble with any of the following, talk to your doctor:

• Breathing: Having trouble catching your breath, feeling short of air, or wheezing. This includes any difficulty breathing in or out.

• Seeing: Problems with your vision, such as blurry or double vision, trouble seeing things clearly, or sudden vision loss.

• Swallowing: Difficulty getting food or liquids down, or feeling like food is getting stuck in your throat. This can also include pain when swallowing.

• Chewing: Problems chewing your food, like pain in your mouth or jaw, or difficulty breaking down food.

• Walking: Having trouble walking, stumbling, or feeling unsteady on your feet. This could be due to pain or weakness.

• Using your arms or hands: If you're having trouble moving your arms or hands, feeling weak or numb in them, or experiencing pain.

• Holding up your head: If you're finding it hard to hold your head up straight, or if you're experiencing neck pain or stiffness that prevents you from doing so.

Important Note: These are just examples of potential problems. If you have any concerns about your health, it's always best to contact your healthcare provider.

Myasthenia Gravis Explained

Your nerves and muscles communicate using special chemicals called neurotransmitters. These neurotransmitters attach to specific spots on muscle cells, called receptor sites. This connection allows your muscles to move.

In myasthenia gravis, a problem with the immune system causes the body to attack and damage the receptor sites, especially those that receive the neurotransmitter acetylcholine. Think of it like a lock and key system. The neurotransmitter is the key, and the receptor site is the lock. When the lock is damaged, the key can't fit properly, and the muscle doesn't receive the signal to move. This leads to muscle weakness.

The immune system can also attack other proteins that help create the connections between nerves and muscles. Proteins like muscle-specific receptor tyrosine kinase (MuSK) and lipoprotein-related protein 4 (LRP4) are crucial parts of the nerve-muscle connection, and attacking them can also result in myasthenia gravis. Scientists are still discovering other proteins and antibodies involved in the disease.

Sometimes, the immune system's attack on the nerve-muscle connection happens without the presence of the antibodies that are often found in other cases. This is called seronegative or antibody-negative myasthenia gravis. While the cause is less clear in these cases, researchers believe it's still related to a problem with the immune system.

The thymus gland, a part of the immune system located in the upper chest, plays a role in myasthenia gravis. In some people, the thymus gland is enlarged or contains tumors (thymomas). These can trigger or maintain the immune system's attack on the receptor sites. While most thymomas are not cancer, some can become cancerous.

In some cases, mothers with myasthenia gravis can pass the condition to their newborns. This is called neonatal myasthenia gravis. Treatment can usually help these babies recover within a few months. There are also rare, inherited forms of myasthenia gravis that babies can be born with.

Several factors can make myasthenia gravis symptoms worse:

• Fatigue: Being tired often worsens the symptoms.
• Illness or infection: Getting sick can trigger or worsen the muscle weakness.
• Surgery: Some surgical procedures can make symptoms worse.
• Stress: Stressful situations can also impact symptoms.
• Certain medications: Some common medications, including beta-blockers, quinidine, quinine, phenytoin, certain anesthetics, and some antibiotics, can worsen the condition.
• Pregnancy and menstruation: These hormonal changes can sometimes affect symptoms.

It's important to note that the severity of myasthenia gravis can vary greatly from person to person. If you experience muscle weakness or other symptoms, it's crucial to consult a doctor for proper diagnosis and treatment.

Myasthenia gravis can lead to serious problems, although most are manageable. Some complications, however, are very dangerous.

One serious complication is called a myasthenic crisis. This happens when the muscles that help you breathe become too weak. This is a medical emergency. People in myasthenic crisis need immediate help breathing, often with a machine called a ventilator. Doctors may use medicines and special treatments to help the body filter out toxins, which can improve breathing.

Sometimes, people with myasthenia gravis have a tumor in the thymus gland. The thymus is a part of the immune system, located just behind the breastbone. Most of these tumors (called thymomas) aren't cancerous, but they can still cause problems.

People with myasthenia gravis might also be more likely to develop other health issues:

• Thyroid problems: The thyroid is a gland in your neck that makes hormones controlling how your body uses energy. If your thyroid is underactive (hypothyroidism), you might feel cold, gain weight, and have other problems. An overactive thyroid (hyperthyroidism) can cause problems like feeling too hot, losing weight, and other issues.

• Other autoimmune conditions: Myasthenia gravis is an autoimmune disease. This means the body's immune system mistakenly attacks its own tissues. People with myasthenia gravis may have a higher chance of also developing other autoimmune conditions, such as rheumatoid arthritis or lupus. These are conditions where the immune system attacks healthy parts of the body.

To diagnose myasthenia gravis, your doctor will first review your symptoms and medical history and perform a physical exam. They might also use several tests:

Physical Examination for Neurological Function: Your doctor will assess your neurological health by checking:

• Reflexes: The automatic responses your body makes, like a knee-jerk reaction.
• Muscle Strength: How much force your muscles can exert.
• Muscle Tone: The firmness of your muscles at rest.
• Senses: Your ability to feel touch and see.
• Coordination: How smoothly you move.
• Balance: Your ability to maintain stability.

Tests to Confirm Myasthenia Gravis:

• Ice Pack Test (for droopy eyelids): If you have a drooping eyelid, your doctor might put an ice pack on it for two minutes. They'll then see if the eyelid has improved, suggesting myasthenia gravis. This is a simple test that helps point towards the condition.

• Blood Test: A blood test can look for unusual antibodies. These antibodies can interfere with the way nerves communicate with muscles, which is a key characteristic of myasthenia gravis.

• Nerve Conduction Study: Electrodes are placed on your skin over the muscles being tested. Small electrical pulses are sent through the electrodes. This measures if the nerve can send signals to the muscle. The test is repeated several times to see if the nerve's ability to send signals gets weaker with repeated use (fatigue). This helps doctors understand how the nerves are functioning.

• Electromyography (EMG): This test measures the electrical activity between your brain and muscles. A thin wire electrode is inserted into a muscle to test the activity of a single muscle fiber. This test provides detailed information about the electrical signals in your muscles.

• Imaging Tests (CT or MRI): A CT scan or MRI might be used to check for any tumors or problems in your thymus gland. The thymus is a gland in your chest that plays a role in the immune system. Sometimes, problems with the thymus can be linked to myasthenia gravis.

• Pulmonary Function Tests: These tests assess how well your lungs are working. Myasthenia gravis can sometimes affect breathing, so these tests help determine if the condition is impacting your respiratory system.

These tests, combined with your symptoms and medical history, help your doctor reach a diagnosis of myasthenia gravis.