BACKGROUND: Cognitive inhibition processes were found to be deficient early in the clinical course of Alzheimer's disease (AD). The inhibition of redundant information is a precondition for efficient cognitive processing and presumably modulated by prefrontal attentional networks. Deficits in the suppression of the evoked potential P50 response to paired clicks are well known in schizophrenic patients and undergo cholinergic modulation. In this study, we aimed to investigate inhibitory gating deficits of P50 in AD and their relation to neuropsychological measures. METHOD: P50 suppression was assessed in 19 AD-patients in comparison to a young and elderly control group (n=17 each) and related to MMSE and specific neuropsychological assessments. RESULTS: Patients showed reduced sensory gating compared to healthy elderly (p<0.021) and exhibited significantly higher N40-P50-amplitudes. There were no age or gender effects in controls. Frontal neuropsychological tests (TMT-B, verbal fluency) and working memory requiring inhibition, but not declarative memory functions, were significantly correlated with inhibitory gating and test amplitude in both, AD-patients and controls. CONCLUSIONS: The results support an early inhibitory deficit interfering with executive functions and working memory in AD independent from physiological aging. P50 gating might be applicable as a marker for inhibition deficits and thereby be important for prognosis estimation. Copyright 2008 Elsevier Inc. All rights reserved.
BACKGROUND: Cognitive inhibition processes were found to be deficient early in the clinical course of Alzheimer's disease (AD). The inhibition of redundant information is a precondition for efficient cognitive processing and presumably modulated by prefrontal attentional networks. Deficits in the suppression of the evoked potential P50 response to paired clicks are well known in schizophrenicpatients and undergo cholinergic modulation. In this study, we aimed to investigate inhibitory gating deficits of P50 in AD and their relation to neuropsychological measures. METHOD:P50 suppression was assessed in 19 AD-patients in comparison to a young and elderly control group (n=17 each) and related to MMSE and specific neuropsychological assessments. RESULTS:Patients showed reduced sensory gating compared to healthy elderly (p<0.021) and exhibited significantly higher N40-P50-amplitudes. There were no age or gender effects in controls. Frontal neuropsychological tests (TMT-B, verbal fluency) and working memory requiring inhibition, but not declarative memory functions, were significantly correlated with inhibitory gating and test amplitude in both, AD-patients and controls. CONCLUSIONS: The results support an early inhibitory deficit interfering with executive functions and working memory in AD independent from physiological aging. P50 gating might be applicable as a marker for inhibition deficits and thereby be important for prognosis estimation. Copyright 2008 Elsevier Inc. All rights reserved.
Authors: Marijn Lijffijt; F Gerard Moeller; Nash N Boutros; Scott Burroughs; Scott D Lane; Joel L Steinberg; Alan C Swann Journal: J Psychophysiol Date: 2009 Impact factor: 1.333
Authors: Oleg Korzyukov; Eishi Asano; Valentina Gumenyuk; Csaba Juhász; Michael Wagner; Robert D Rothermel; Harry T Chugani Journal: Brain Topogr Date: 2009-08-22 Impact factor: 3.020
Authors: Marijn Lijffijt; Scott D Lane; Stacey L Meier; Nash N Boutros; Scott Burroughs; Joel L Steinberg; F Gerard Moeller; Alan C Swann Journal: Psychophysiology Date: 2009-06-08 Impact factor: 4.016