Affiliations: [a] Clinical Neuroscience Unit of Dementia, Dementia Research Center, IRCCS Mondino Foundation, Pavia, Italy
| [b] Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| [c] Neuroradiology Department, Advanced Imaging and Radiomics Center, IRCCS Mondino Foundation, Pavia, Italy
| [d] Clinical Neurophysiology Unit, IRCCS Mondino Foundation, Pavia, Italy
| [e] Unit of Behavioral Neurology and Center for Cognitive Disorders and Dementia (CDCD), IRCCS Mondino Foundation, Pavia, Italy
Correspondence:
[*]
Correspondence to: Matteo Cotta Ramusino, Clinical Neuroscience Unit of Dementia, Dementia Research Center, IRCCS Mondino Foundation, Pavia, Italy. E-mail: [email protected].
Abstract: Background:The clinical features of posterior cortical atrophy (PCA), a rare condition often caused by Alzheimer’s disease, have been recently defined, while little is known about its neurophysiological correlates. Objective:To describe neurophysiological alterations of the visual pathway as assessed using visual field test (VF), visual evoked potentials (VEP), and electroretinogram (ERG) in PCA patients. Methods:Studies reporting VF, VEPs, and ERG in PCA patients were selected according PRISMA method. Of the 323 articles that emerged from the literature, 17 included the outcomes of interest. To these data, we added those derived from a patient cohort enrolled at our clinic. Results:The literature review included 140 patients, half of them (50%) presented with homonymous hemianopia or quadrantanopia. VEPs were available in 4 patients (2 normal findings, 1 decreased amplitude, and 1 increased latency) and ERG in 3 patients (substantially normal findings). Our case series included 6 patients, presenting with homonymous lateral hemianopia in 50% and contralateral cortical atrophy. VEPs showed normal amplitude in 66–83% according to the stimulation check, and increased latency in 67% in absence of myelin damage on MRI. Latency was increased in both eyes in 50% and only on one side in the other 50%. Such alterations were observed in patients with more severe and symmetric atrophy. ERG showed normal findings. Conclusions:Neurophysiological investigations of the visual pathway in PCA are almost absent in literature. Alterations involve both amplitude and latency and can be also monocular. A multiple-point involvement of the optical pathway can be hypothesized.
