[Parinaud syndrome : a diplopia unlike any other].

Sudden-onset diplopia warrants an emergency management in ophthalmology. A binocular, vertical and persistent diplopia, should raise suspicion of a central lesion, particularly within the brainstem. We reporte the case of a 53-year-old man, who presented with acute vertical binocular diplopia. Ophthalmological examination revealed a bilateral elevation limitation, characteristic of Parinaud's syndrome. Brain magnetic resonance imaging identified a right-sided ischemic midbrain infarction, and further cardiovascular work-up demonstrated a patent foramen ovale causing a right-to-left shunt.