Which autoimmune disorder is known to have symptoms that mimic myasthenia gravis?

Eaton-Lambert Syndrome is indeed an autoimmune disorder that can present with symptoms similar to those of myasthenia gravis. Both conditions involve neuromuscular transmission issues, but they differ in their pathophysiology. In myasthenia gravis, antibodies typically target acetylcholine receptors at the neuromuscular junction, leading to muscle weakness that worsens with activity. Eaton-Lambert Syndrome, on the other hand, results from antibodies that inhibit the release of acetylcholine, which also leads to muscle weakness, particularly with repeated use of the muscles.

The specific overlap in symptoms, such as muscle weakness and fatigue, is significant because it can create diagnostic challenges. In particular, both conditions can produce ocular symptoms like ptosis or diplopia, making it difficult to distinguish between them without specific tests to identify the underlying cause.

The other disorders listed do not have the same direct impact on neuromuscular transmission. Multiple sclerosis primarily affects the central nervous system, whereas Graves' disease primarily involves thyroid dysfunction and can result in symptoms like hyperthyroidism and exophthalmos. Rheumatoid arthritis is an inflammatory joint disease and does not typically cause the muscle weakness seen in myasthenia gravis or Eaton-Lam