OBJECTIVE: We developed visual motion evoked potential (EP) measures related to navigational impairment in Alzheimer disease (AD) and have now applied these methods to explore the role of elementary perceptual and attentional mechanisms mediating these effects. METHODS: Older adult (OA) control subjects and AD patients underwent visual motion perceptual testing, attentional performance monitoring, and basic neuropsychological and visual assessments. We recorded stationary pattern onset and visual motion onset EPs as well as behavioral event-related potentials during centered visual fixation. RESULTS: Psychophysical assessment demonstrated visual motion perceptual impairments in patients with AD, half of whom also showed low sensitivity in the attentional task. The low sensitivity AD patients had small pattern onset and absent motion onset EPs, whereas the high sensitivity AD patients had large pattern onset EPs and normal motion onset EPs. CONCLUSIONS: We conclude that visual evoked potentials (EPs) are abnormal in all patients with Alzheimer disease (AD): Those with small pattern and motion onset EPs may have greater AD pathology in visual cortex, whereas those with larger pattern onset EPs may have greater AD pathology in higher centers. These findings highlight the utility of visual EPs in distinguishing between syndromic variants of AD associated with particular patterns of functional decline.
OBJECTIVE: We developed visual motion evoked potential (EP) measures related to navigational impairment in Alzheimer disease (AD) and have now applied these methods to explore the role of elementary perceptual and attentional mechanisms mediating these effects. METHODS: Older adult (OA) control subjects and ADpatients underwent visual motion perceptual testing, attentional performance monitoring, and basic neuropsychological and visual assessments. We recorded stationary pattern onset and visual motion onset EPs as well as behavioral event-related potentials during centered visual fixation. RESULTS: Psychophysical assessment demonstrated visual motion perceptual impairments in patients with AD, half of whom also showed low sensitivity in the attentional task. The low sensitivity ADpatients had small pattern onset and absent motion onset EPs, whereas the high sensitivity ADpatients had large pattern onset EPs and normal motion onset EPs. CONCLUSIONS: We conclude that visual evoked potentials (EPs) are abnormal in all patients with Alzheimer disease (AD): Those with small pattern and motion onset EPs may have greater AD pathology in visual cortex, whereas those with larger pattern onset EPs may have greater AD pathology in higher centers. These findings highlight the utility of visual EPs in distinguishing between syndromic variants of AD associated with particular patterns of functional decline.
Authors: Mark W Albers; Grover C Gilmore; Jeffrey Kaye; Claire Murphy; Arthur Wingfield; David A Bennett; Adam L Boxer; Aron S Buchman; Karen J Cruickshanks; Davangere P Devanand; Charles J Duffy; Christine M Gall; George A Gates; Ann-Charlotte Granholm; Takao Hensch; Roee Holtzer; Bradley T Hyman; Frank R Lin; Ann C McKee; John C Morris; Ronald C Petersen; Lisa C Silbert; Robert G Struble; John Q Trojanowski; Joe Verghese; Donald A Wilson; Shunbin Xu; Li I Zhang Journal: Alzheimers Dement Date: 2014-07-09 Impact factor: 21.566
Authors: Andrea N Snyder; Marcie A Bockbrader; Angela M Hoffa; Mario A Dzemidzic; Thomas M Talavage; Donald Wong; Mark J Lowe; Brian F O'Donnell; Anantha Shekhar Journal: Neuropsychology Date: 2011-09 Impact factor: 3.295