A 72 year old man complains of drooping of lids for last 2 months. On awakening he is able to open his eyes, but few hours later his ptosis progressively worsens with increasing diplopia most likely diagnosis?
Thyroid ophthalmopahty
Horner's syndrome
Myasthenia gravis
3rd nerve Palsy
Myasthenia gravis is a disease characterized by generalized muscular weakness and rapidly developing fatigue of the muscles due to an auto-immune disorder in which damage of the acetylcholine receptors takes place at the post-synaptic membrane. Anti-acetylcholine receptor antibodies are found in approximately 80% of patients with myasthenia, the levels correlating with the severity of the disease. The ptosis is nearly always bilateral and is increased by prolonged fixation or attempts to look upwards; effective compensation by overaction of the frontales is impossible. Ophthalmoplegia externa, paial or complete, occurs in 50% of the cases, but the intrinsic muscles are not affected. Nystagmoid jerks are not uncommon.
Neuro Ophthalmology