myasthenia gra·vis -'grav-əs, -'gräv- n a disease characterized by progressive weakness and exhaustibility of voluntary muscles without atrophy or sensory disturbance and caused by an autoimmune attack on acetylcholine receptors at neuromuscular junctions
* * *
a chronic disease marked by abnormal fatigability and weakness of selected muscles, which is relieved by rest and steroids. The degree of fatigue is so extreme that these muscles are temporarily paralysed. The muscles initially affected are those around the eyes, mouth, and throat, resulting in drooping of the upper eyelids (ptosis), double vision, dysarthria, and dysphagia. Myasthenia gravis is an autoimmune disease in which autoantibodies bind to cholinergic receptors on muscle cells, which impairs the ability of the neurotransmitter acetylcholine to induce muscular contraction. Treatment with anticholinesterase drugs and surgical removal of the thymus in younger patients (under the age of 45 years) lessen the severity of the symptoms. Steroid therapy or plasma exchange may be used to treat the more severely affected patients.
* * *
an autoimmune disease of neuromuscular function due to the presence of antibodies to acetylcholine receptors at the neuromuscular junction; characteristics include muscle fatigue and exhaustion that fluctuates in severity, without sensory disturbance or atrophy. It may be restricted to one muscle group or become generalized with severe weakness and sometimes respiratory insufficiency. It may affect any muscle of the body, but especially those of the eyes, face, lips, tongue, throat, and neck. Called also Erb-Goldflam, Goldflam, or Goldflam-Erb disease.Medical dictionary. 2011.