Rosh Internal Medicine Boost Practice Exam

Which symptom is common in a patient suffering from myasthenia gravis, particularly late in the day?

1. Double vision

2. Chest pain

3. Increased appetite

4. Severe headache

The correct answer is: Double vision

In myasthenia gravis, a hallmark symptom is fluctuating muscle weakness that worsens with activity and improves with rest. This condition is caused by an autoimmune response that leads to a reduction in acetylcholine receptors at the neuromuscular junction, resulting in insufficient communication between nerves and muscles. Double vision, also known as diplopia, is a common manifestation in myasthenia gravis. It occurs due to weakness of the extraocular muscles that control eye movement. Throughout the day, as a person uses these muscles for activities such as reading or focusing, the symptoms tend to worsen, leading to increased diplopia or difficulty maintaining eye position. By resting, the weakness may temporarily improve, but the tiredness of the muscles typically leads to more pronounced symptoms as the day progresses. The other options—chest pain, increased appetite, and severe headache—do not have the same direct association with the muscle fatigue characteristic of myasthenia gravis. While a patient might experience chest discomfort due to respiratory muscle involvement in severe cases, it is not a common or defining symptom of the condition. Increased appetite is unrelated to the muscular symptoms of myasthenia gravis, and severe headache is not typically a feature associated with myas