Stress and overwork often leave people feeling weak and lethargic. Still, when this fatigue becomes so severe that it interferes with basic tasks, it could be a sign of myasthenia gravis, a severe condition that requires immediate attention.
On Wednesday, neurologists explained that myasthenia gravis is an autoimmune disorder in which the body’s immune system mistakenly attacks healthy tissues. This leads to impaired communication between the brain and muscles through motor nerves, resulting in weakness. The condition, which was first identified in the 19th century, is called “grave” because, if left untreated, it can lead to respiratory failure.
The key symptoms of myasthenia gravis are muscle weakness and fatigue. In its early stages, patients often experience weakness in the ocular muscles, leading to drooping eyelids and double vision (diplopia). Facial muscle weakness can also interfere with chewing, speaking, and swallowing.
Dr. Kim Seung Woo, a neurologist at Yonsei University Severance Hospital, explained: “At first, a person may be able to raise their arms to wash their hair, but over time, their strength decreases, and they need to rest. Similarly, chewing tough foods becomes harder as muscle fatigue sets in.” He added that activities like watching TV can worsen symptoms, with double vision and eyelid drooping intensifying. Symptoms tend to worsen as the day progresses, and patients can track changes by comparing photos from morning to evening.
While 15% of patients experience only ocular symptoms, the remaining 85% develop weakness in other muscle groups, including the limbs. In severe cases, respiratory muscles can weaken, leading to shortness of breath and, in extreme cases, suffocation, requiring mechanical ventilation.
Dr. So Jung Min, a neurologist at Korea University Ansan Hospital, explained the difference between fatigue and myasthenia gravis: “Lethargy feels like a lack of energy but doesn’t typically affect muscle strength during tasks. In contrast, myasthenia gravis patients struggle to maintain strength when lifting objects or exerting effort.”
Diagnosing myasthenia gravis requires a neurologist’s evaluation. Tests may include repetitive nerve stimulation, acetylcholine receptor antibody measurements, and anticholinesterase medication trials. Repetitive nerve stimulation involves applying electrical stimuli to weakened muscles to assess fatigue. Antibody tests detect myasthenia gravis-triggering substances in the blood, with about 70% of patients showing anti-acetylcholine receptor antibodies.
The medication trial involves administering drugs that temporarily enhance nerve-muscle signal transmission to observe symptom improvement. If practical, patients may experience relief from eyelid drooping, double vision, limb weakness, and speech difficulties.
After diagnosis, a chest CT scan is typically performed to evaluate the thymus gland. In myasthenia gravis patients, the thymus abnormally produces disease-causing autoantibodies, contributing to the condition.
The early stages of myasthenia gravis may involve fluctuating muscle weakness and improvement, with some symptoms disappearing entirely. However, the condition often worsens over time and spreads throughout the body. This makes consistent treatment crucial to managing the disease. The primary goal is maintaining immune function, preventing disease progression, and managing symptoms effectively.
Patients may be prescribed symptom-relieving medications such as acetylcholinesterase inhibitors, immunosuppressants, and corticosteroids. While these medications can offer rapid symptom relief, patients with inadequate control may require additional treatments like intravenous immunoglobulin and plasmapheresis. These treatments remove myasthenia gravis-causing substances from the blood and can improve symptoms within 1-2 weeks, but their effects usually last only 1-3 months.
While aggressive immunosuppressive treatments can produce rapid and significant results, they may cause severe side effects. As a result, it’s important to maintain a treatment regimen that balances symptom relief with minimizing side effects.
Dr. So emphasized, “Myasthenia gravis requires lifelong attention. Patients can maintain a relatively normal lifestyle with early detection and consistent treatment. However, some patients stop their medication and skip follow-up appointments, which highlights the importance of ongoing medical care and monitoring.”