What is the definition or description of: myasthenia gravis?

Neuromuscular dz: MG is an autoimmune disease of the neuromuscular junction, where there is inhibition of transmission of an impulse at the post-synaptic acetylcholine receptors. Patients present with involvement often of the ocular musculature (ptosis, double vision etc.) but can also have extremity weakness as well. EDx testing with repetitive stimulation and single fiber EMG can be helpful for diagnosis.