Myasthenia Gravis: When Muscles Fatigue Very Easily

Imagine waking up feeling great, but as the day progresses, simple tasks like brushing your hair or keeping your eyes open become difficult. That’s the daily grind for people living with myasthenia gravis (MG), a condition in which muscles tire very quickly due to a breakdown in communication between nerves and muscles.

Myasthenia gravis is a rare neuromuscular disorder that affects voluntary muscles, especially those that control the eyes, face, neck, and limbs. While it can be a serious condition, it’s manageable with the right treatment. Let’s delve into the science behind MG and how it affects those who have it.

What causes myasthenia gravis?

Our muscles rely on acetylcholine, a neurotransmitter that carries signals from nerves to muscles, telling them to contract. In MG, the immune system produces antibodies that block or destroy acetylcholine receptors, preventing the signal from reaching the muscles. This results in easy and rapid fatigue and therefore muscle weakness.

MG is therefore an autoimmune disease, meaning that the body's defense system mistakenly attacks itself. The exact cause is unknown, but it is thought that a malfunction of the thymus gland may play a role in some cases. The thymus gland regulates the immune system and abnormalities such as thymomas (tumors) or hyperplasia are seen in many patients with MG.

Symptoms: Not just muscle fatigue

The characteristic symptom of MG is muscle weakness that worsens with activity and improves with rest. Symptoms vary from person to person, but common ones include:

• Dropped eyelid - A telltale sign of MG, often noticed in the afternoon and evening hours.

• Double vision (diplopia) - Weak eye muscles cause misalignment, resulting in seeing double images.

• Difficulty swallowing (dysphagia) and speaking (dysarthria) - Weakness in the muscles of the throat and face makes chewing and speaking a challenge.

• Weakness in the limbs and neck - Some people have difficulty raising their arms, holding their head up, or walking.

• Severe cases: Myasthenic crisis - If the respiratory muscles weaken, breathing can become difficult, requiring emergency treatment in a hospital setting.

The “Thinker’s Posture” – A Characteristic Sign of MG

An interesting sign of MG is the “Thinker’s Posture.” People with MG who experience drooping eyelids and head often lift their chin and prop their eyelid with their hand while reading or watching television. This compensatory movement, reminiscent of Rodin’s famous statue “The Thinker,” is a subtle but telling sign of the condition.

Who gets myasthenia gravis?

MG can affect people of all ages, but certain groups are at higher risk:

• Women under 40 and men over 60 are more likely to develop the disease.

• Genetics may play a role, but MG is not directly inherited.

• Other autoimmune disorders may be associated with MG.

Diagnosis of myasthenia gravis

Diagnosis can be difficult, as the symptoms can resemble other neurological conditions. A thorough physical examination is very important, which can detect muscle weakness in specific muscle groups, especially during exercise tests. However, in addition to physical examination, various tests are used, such as:

• Ice pack test - Placing an ice pack on the eyelid can temporarily improve ptosis, providing an easy and quick first indication.

• Edrophonium test – Administration of a drug that briefly improves muscle strength, suggesting a diagnosis of MG.

• Electromyography (EMG) – Evaluates communication between nerves and muscles, detecting muscle fatigue with repeated stimulation.

• Blood tests – Detect antibodies to acetylcholine receptors (AChR), as well as MuSK (muscle-specific kinase) and LRP4 (low-density lipoprotein receptor-related protein 4), which are associated with different subtypes of MG.

• CT scan or MRI – Checks for abnormalities in the thymus gland.

Treatment: Fighting Weakness

While there is no definitive cure for MG, treatments can significantly improve symptoms. Options include:

• Cholinesterase inhibitors (e.g., pyridostigmine) - Help acetylcholine work better.

• Corticosteroids & immunosuppressants - Reduce the immune system's attacks on receptors.

• Plasmapheresis & IVIG - Given in more urgent situations and remove harmful antibodies or modulate the immune response.

• Thymectomy - Removal of the thymus gland may lead to improvement, especially in cases with thymomas.

Recent Developments in MG Treatment

Medical research has led to the development of new treatments for MG, especially for people with severe or treatment-resistant cases:

- Complement inhibitors - Drugs such as eculizumab and ravulizumab target the immune system's complement pathway, reducing damage to acetylcholine receptors.

- FcRn inhibitors - Newer treatments such as efgartigimod work by reducing harmful antibodies in the bloodstream, offering an alternative to traditional immunosuppressants.

- Targeted biologics - Research into monoclonal antibodies offers hope for more personalized treatment approaches in the future.

Living with Myasthenia Gravis

Living with MG requires adjustments, but many people live very normal lives.

- Energy management - Scheduling activities during times of higher energy can help reduce fatigue.

- Coping strategies - Using tools such as special glasses for diplopia or eating softer foods can make everyday challenges easier.

- Support networks - Connecting with patient groups and specialists can provide guidance and encouragement.

- Medical awareness - Informing doctors, nurses, and emergency personnel about MG ensures appropriate care in case of complications.

- Regular neurological monitoring - checking symptoms, possible treatment modifications to improve daily life and avoid deterioration or complications.

Famous People with MG

Although MG is rare, some well-known figures have lived with the condition, helping to raise public awareness:

- Aristotle Onassis - The famous Greek shipping magnate reportedly had MG, which affected his ability to keep his eyelids open.

- Raghib Ismail ("Rocket" Ismail) - Former NFL player who spoke publicly about managing MG while remaining active in sports.

- Sir Lawrence Olivier - The legendary British actor experienced muscle weakness and fatigue later in his career, which was thought to be due to MG.

- Henrique Mecking - Brazilian chess grandmaster, whose career was interrupted by MG, but later returned.

- Sleepy – the Sleepyhead from the children’s fairy tale “Snow White and the Seven Dwarfs” - It is rumored that the character Sleepyhead was inspired by a friend of Walt Disney who had MG, exhibiting the classic symptom of drooping eyelids.

Conclusion

Myasthenia gravis is a complex but manageable neurological condition. With appropriate treatment and lifestyle adjustments, many patients live normal lives. Science is advancing, and with continued research, the future for people with MG looks promising.