The resulting study was negative. Myasthenia gravis is a condition characterized by abnormal fatigability of the striated muscles after repetitive contraction which improves with rest. It is a disease of the myoneural junction where abnormal antibodies bind to the acetylcholine receptors. The incidence of the condition is approximately 1 in 20,000 to 1 in 30,000. Onset of symptoms may follow upper respiratory tract infection, stress, or pregnancy.
Myasthenia often presents with ocular signs and symptoms.
The most common finding is ptosis. Diplopia is also common and is frequently varys over time. Myasthenia is capable of simulating any isolated or multiple extraocular muscle palsy and may be mistaken for a supranuclear process e.g. internuclear ophthalmoplegia or gaze palsies. The hallmarks of myasthenia are variability, fatigability, and orbicularis weakness. The presence of pupil involvement or decreased vision should raise the possibility of diagnoses other than myasthenia.