This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
Antibodies to calcium channel are seen in 
Select and explain. 
A. Eaton lambe syndrome, B. Dermatomyositis, C. Myaesthenia gravis, D. Polymyositis
A: Eaton lambe syndrome
Answer: A: Eaton lambe syndrome 
Explanation: Lambe-Eaton syndrome presents with proximal muscle weakness that improves with exercise & is caused by the development of antibodies to presynaptic calcium channels. Myasthenia gravis is autoimmune disease caused by the development of antibodies to postsynaptic acetylcholine receptors.Polymyositis & Dermatomyositis are related disorders that are characterised by an inflammatory process affecting skeletal muscle. In dermatomyositis,characteristic skin changes also occur. Davidson's Medicine-22nd edition,page no:272,1114,1226,1227