Which condition is associated with progressively common bouts of fatigue alongside muscular weakness?

Myasthenia gravis is a neuromuscular disorder characterized by weakness and rapid fatigue of voluntary muscles. The condition results from an autoimmune response where antibodies block or destroy the communication between nerves and muscles. This leads to varying degrees of muscle weakness, particularly with sustained activity. A hallmark feature is the exacerbation of weakness with repeated use of the affected muscle groups, which aligns with the symptoms of progressively common bouts of fatigue and muscular weakness.

The other conditions mentioned relate to joint and muscle issues but do not primarily manifest as a pattern of profound fatigue alongside muscle weakness in the same way. Osteoarthritis and rheumatoid arthritis primarily involve joint pain and stiffness, while contracture refers to a shortening or tightening of muscles or tendons, which does not typically cause the fluctuating fatigue and weakness symptoms seen in myasthenia gravis. Thus, the correct identification of myasthenia gravis directly addresses the relationship between fatigue and muscle weakness as key features of the condition.