Retinal and Cortical Visual Processing Dysfunction in a Case of Mild Cognitive Impairment with Lewy Bodies: A Case Report.

The prodromal stage of Lewy body dementia includes a mild cognitive impairment with visual processing and/or attention-executive deficits. A clinical presentation with progressive visual loss is indeed seldom reported and can be misleading with a posterior cortical atrophy disease. While the neurodegeneration at the occipital cortex can only partially explain the visual disturbances of Lewy body dementia, more recently a retinal dysfunction has been suggested by preliminary optical coherence tomography and autoptic findings. Herein, we present a case of a mild cognitive impairment with Lewy bodies, who presented initially with visual disturbances and signs of both retinal and cortical visual processing dysfunction. A complete neuropsychological, neurophysiological and brain imaging assessment highlighted a prominent ventral visual pathway involvement. This report provides first that the prodromal stage of Lewy body dementia can manifest as a primarily progressive visual loss, second that the involvement of visual pathway, particularly the ventral stream, can be detectable from the retinal to the cortical level.