Biological psychiatry · 2011
Asymmetric loss of parietal activity causes spatial bias in prodromal and mild Alzheimer's disease.
СтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Sorg Christian, Myers Nicholas, Redel Petra, Bublak Peter, Riedl Valentin, Manoliu Andrei, Perneczky Robert, Grimmer Timo, Kurz Alexander, Förstl Hans, Drzezga Alexander, Müller Hermann J, Wohlschläger Afra M, Finke Kathrin
Аннотация
BACKGROUND: In Alzheimer's disease (AD), loss of effective neuronal activity is reflected by cortical glucose hypometabolism. Hypometabolism in the posterior parietal cortex (PPC) is among the first in vivo signs of AD; however, its functional impact on large-scale brain mechanisms and behavior is poorly understood. The lateral PPC contributes to spatial attention constituting a basic function of the human brain. We hypothesized 1) that lateral PPC hypometabolism is associated with impaired spatial attention in very early AD and 2) that impaired competition of effective neuronal activity across hemispheres might underlie this deficit in terms of brain mechanisms.
METHODS: A model-based imaging approach was applied to assess patients with prodromal (n = 28) and mild (n = 7) AD. Quantitative attention parameters, derived from performance on simple psychophysical tasks and analyzed by Bundesen's computational theory of visual attention, were related to brain metabolism, measured by (18)F-fluorodeoxyglucose positron emission tomography.
RESULTS: Patients' left and right lateral PPC metabolism was reduced. Nine patients had significant spatial attentional bias on the left side and two patients on the right. Direction and degree of spatial bias was correlated with direction and degree of an interhemispheric metabolism bias in the inferior parietal lobe and temporoparietal junction.
CONCLUSIONS: Our data provide evidence that in very early AD, asymmetric hypometabolism of the lateral PPC causes spatial attentional bias. Results are broadly consistent with the model that asymmetrically impaired effective neuronal PPC activity in AD biases the competition of visual objects for cortical representation and access to awareness to one side.
METHODS: A model-based imaging approach was applied to assess patients with prodromal (n = 28) and mild (n = 7) AD. Quantitative attention parameters, derived from performance on simple psychophysical tasks and analyzed by Bundesen's computational theory of visual attention, were related to brain metabolism, measured by (18)F-fluorodeoxyglucose positron emission tomography.
RESULTS: Patients' left and right lateral PPC metabolism was reduced. Nine patients had significant spatial attentional bias on the left side and two patients on the right. Direction and degree of spatial bias was correlated with direction and degree of an interhemispheric metabolism bias in the inferior parietal lobe and temporoparietal junction.
CONCLUSIONS: Our data provide evidence that in very early AD, asymmetric hypometabolism of the lateral PPC causes spatial attentional bias. Results are broadly consistent with the model that asymmetrically impaired effective neuronal PPC activity in AD biases the competition of visual objects for cortical representation and access to awareness to one side.