Strabismus could cause intermittent diplopia with an acute onset of symptoms (typically with a prior ocular misalignment that was held latent). However, there is no expected association between esotropia and new-onset ptosis. The incomitant deviation measured in this patient would also make strabismus less likely.
Horner syndrome could account for 2-3 mm of ptosis, but would also be expected to be accompanied by miosis and anisocoria (when unilateral). Isolated Horner syndrome would also not be associated with diplopia.
A brainstem stroke would most likely be associated with other neurologic findings, such as dysarthria, dizziness, and weakness. Brainstem stroke resulting in diplopia and ptosis would most likely cause the symptoms to occur simultaneously and not in the progressive fashion noted in this patient.
Orbital myositis most often occurs unilaterally and would be expected to be associated with pain or signs of an orbitopathy, including proptosis.
Myasthenia gravis would be the most likely cause, given the patient's history of transient diplopia occurring years earlier and the current combination of ptosis and diplopia. Myasthenia gravis may occur despite the absence of systemic symptoms. Improvement of ptosis with rest or ice may be suggestive of myasthenia gravis, but is not seen in all patients with this condition. Systemic symptoms, such as trouble with swallowing or breathing, are absent when myasthenia gravis is limited to the ocular form.
Three weeks later, the patient brought an MRI of the brain with contrast from her hospitalization 4 years earlier, which showed some hyperintensities in the cortical white matter on T2-weighted images. There was no evidence of an orbitopathy or abnormality in the brainstem.
Acetylcholine receptor antibodies (binding, blocking, and modulating) were positive.
The patient was referred to a neuromuscular specialist for evaluation and treatment of myasthenia gravis.
Medscape Ophthalmology © 2015
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Ptosis and Diplopia in a 74-Year-Old With History of Stroke - Medscape - Dec 02, 2015.