Visual Evoked Potentials in Alzheimer's Disease:Electrophysiological Study of the Visual Pathways and Neuropsychological Correlates

Visual Evoked Potentials [VEP] abnormalities are reported in Alzheimer’s Disease [AD] patients. It is necessary to understand the pathophysiology, clinical relevance and the relationship with the different visual pathways. We performed a study on AD patients compared to Multi-Infarct Dementia [MID] patients by means of different visual stimuli considered selective in stimulating Magnocellular [M], Parvocellular [P] and Koniocellular [K] system. All the patients underwent a neuropsychological assessment and evaluation of disability. Our results seem to confirm major involvement of both the M system and the K system in AD patients, in accordance with the pathophysiological hypotheses regarding visual disturbances in AD. Moreover, the neurophysiological data seem to be related both to the neuropsychological features of dysexecutive syndrome and apraxia and also to disability.