Visual Mirroring Hallucinatory Variant of Palinopsia - An Atypical Presentation of Occipital and Splenial Infarct
Sayyeda Zahra1, Irene Chu2, Megan Leary1
1Lehigh Valley Health Network, 2Lehigh Valley Hospital - Cedar Crest
Background:
Palinopsia is a rare visual phenomenon that is a distortion of processing during which a static or kinetic image of a persistent visual stimulus occurs after cessation of the initial stimulus. It is usually associated with left-sided visual field disturbances that are contralateral to a right PCA infarct, typically also associated with a contralateral hemianopsia.
Design/Methods:
A 86-year-old man with a history of hypertension presented with sudden onset of a recurrent, transient abnormal visual phenomenon. He reported that if he saw a person to his right, and then looked straight ahead, he immediately saw the same person in his left peripheral vision but in a static, "frozen" image that was no longer moving. Each visual mirroring episode lasted for roughly 30 minutes, occurred once daily for a few days, and involved only people, not objects. Magnetic Resonance Diffusion-weighted Imaging (MRI-DWI) of the brain showed evidence of multiple areas of acute ischemic infarction within the right posterior cerebral artery (PCA) territory, including right splenium of the corpus callosum and right occipital lobe. Routine EEG was negative for seizures and captured one episode. Our impression was that these visual mirroring hallucinations were directly related to his right PCA infarct.
Conclusions:
In classic palinopsia, the hallucinatory image becomes incorporated appropriately into the visual scene being perceived. In our case, patient sees an exact static mirror image of the same person present on his right in his left vision, with the ‘true’ and false images briefly mirroring each other with the true image changing in real time and with the “mirror” image remaining static. This static hallucinatory mirroring visual phenomenon as a variant of palinopsia, due to right posterior cerebral artery infarction has not been previously reported in the literature. The clinical manifestations of this type of infarct can be complex and easily misdiagnosed.