Cerebral polyopia - Neuroimaging localization

Purpose. Cerebral polyopia is a rare visual phenomenon. with an unknown pathophysiology. Previous studies suggested but did not prove it originates from occipital lobe disturbances, either bilateral or of the nondominant hemisphere. There are no reports with documented modern neuroimaging. The purpose of this study was to determine whether the extent of the visual field loss and lesion on neuroimaging could be correlated with the symptoms. Methods. Case review of 2 patients (only 2 seen by referral neuro-ophthalmology service in 15 years) with acute onset of monocular diplopia of cerebral origin without other causes of monocular diplopia. Heuro-ophthalmic evaluations and CT scans and MRI were reviewed. Results. Both patients were right handed, had normal exams except for dense right homonymous hemianopia sparing the macula in one. Neither had parietal lobe or speech problems. The CT/MRI of each patient revealed a large left occipital infarct sparing the lateral cortex, worse superiorly in 1 and worse inferiorly in the second. One stopped having polyopia without field improvement in three days and the second improved within two weeks with minimal field improvement. Conclusions. Central monocular diplopia seems to originate from a purely occipital lesion. The exact pathophysiology remains unclear and it can occur in the dominant hemisphere.