Understanding Myasthenia Gravis: Symptoms, Causes, Diagnosis and Treatment

Understanding Myasthenia Gravis (MG)

Myasthenia gravis (MG) is a chronic autoimmune disorder that leads to muscle weakness and severe fatigue. It occurs when the immune system mistakenly attacks healthy tissue, specifically the acetylcholine receptors located on muscle cells. Acetylcholine is a neurotransmitter responsible for stimulating muscle contraction, and when these receptors are impaired, communication between nerves and muscles breaks down.

What Causes MG?

Researchers still don't know exactly what triggers the immune system to start producing antibodies that target acetylcholine receptors. There may be both genetic and environmental factors at play. Some theories include:

• Genetic predisposition: MG runs in families, suggesting a genetic component.
• Thymus abnormalities: Many patients have tumors or other issues with the thymus gland which produces immune cells.
• Viral infections: Previous viral illnesses may trigger an autoimmune reaction.

In most cases, MG is acquired rather than inherited. The onset of symptoms usually occurs between 20-40 years old for women and 50-70 years old for men, though MG can impact people of any age.

MG Signs and Symptoms

The primary symptom of myasthenia gravis is muscle weakness that progressively worsens with activity and improves with rest. The exact pattern of weakness varies greatly among patients, but can include:

• Drooping eyelids (ptosis)
• Blurry or double vision
• Difficulty speaking clearly
• Chewing and swallowing problems
• Limb weakness
• Neck and facial muscle weakness

This characteristic pattern of worsening weakness with exertion and temporary relief with rest is key to diagnosing MG. Patients may experience "myasthenic crises" - sudden severe flare-ups of symptoms that require prompt medical care.

Getting Diagnosed with Myasthenia Gravis

Because MG causes vague, variable muscle weakness, it can be tricky to diagnose. Your doctor will start by taking a complete medical history and performing a physical and neurological exam.

They will look for fatigable weakness that worsens with repetitive movement. Diagnostic tests that can help confirm MG include:

Blood Tests

About 85% of people with generalized MG will have elevated levels of acetylcholine receptor antibodies in their blood. This helps confirm impaired communication between nerves and muscle.

Nerve Conduction Studies

Electrodes measure muscle response when a nerve is stimulated. With MG, conduction declines after rapid stimulation.

Edrophonium Test

This medication temporarily increases acetylcholine availability. A positive response - brief improvement in muscle strength - helps confirm impaired neuromuscular transmission.

Pulmonary Function Tests

Since MG can affect breathing muscles, your doctor may order pulmonary function tests to check for shortness of breath or weakened respiration. Reduced vital capacity often indicates respiratory involvement.

Treatment Options for Myasthenia Gravis

While there is no cure for MG, various treatments can control symptoms long-term and bring significant improvement. The main treatment approaches include:

Medications

Drug options aim to improve communication at the neuromuscular junction. These include:

• Acetylcholinesterase inhibitors: These slow the breakdown of acetylcholine
• Immunosuppressants: Help modify abnormal immune system activity
• Corticosteroids: Powerful anti-inflammatories that suppress immune overactivity

Plasmapheresis

This procedure filters the blood to remove harmful antibodies. It brings rapid but temporary improvement when approaching myasthenic crisis.

Intravenous Immunoglobulin (IVIg)

IVIg delivers healthy antibodies to help regulate the immune system. Like plasmapheresis, benefits only last several weeks.

Surgery

Many patients have their thymus gland removed to eliminate abnormalities. Surgery can lead to medication reduction or even remission in some cases.

Physical Therapy

Specialized exercise programs help MG patients build strength and prevent complications from inactivity like contractures or pneumonia.

Living with Myasthenia Gravis

MG is a lifelong condition, but patients can enjoy long periods of remission. Ongoing care aims to manage fluctuations and prevent crises. Tips for living with MG include:

• Get plenty of rest between activities
• Pace daily tasks with scheduled rest breaks
• Build energy conservation into your lifestyle
• Learn to recognize personal warning signs of impending flare-ups
• Carry prednisone or emergency meds in case of sudden weakness
• Use eye patches for drooping lids; eat soft foods when chewing fatigues
• Join a support group to connect with other MG patients

Staying ahead of this relapsing-remitting disease requires diligent self-care and help from loved ones. But patients who understand warning signs and stick to tailored treatment plans can manage symptoms successfully.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.