%0 Journal Article
%T Quantitative EEG Markers in Mild Cognitive Impairment: Degenerative versus Vascular Brain Impairment
%A D. V. Moretti
%A O. Zanetti
%A G. Binetti
%A G. B. Frisoni
%J International Journal of Alzheimer's Disease
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/917537
%X We evaluated the relationship between brain rhythmicity and both the cerebrovascular damage (CVD) and amygdalohippocampal complex (AHC) atrophy, as revealed by scalp electroencephalography (EEG) in a cohort of subjects with mild cognitive impairment (MCI). All MCI subjects underwent EEG recording and magnetic resonance imaging. EEGs were recorded at rest. Relative power was separately computed for delta, theta, alpha1, alpha2, and alpha3 frequency bands. In the spectral band power the severity of CVD was associated with increased delta power and decreased alpha2 power. No association of vascular damage was observed with alpha3 power. Moreover, the theta/alpha1 ratio could be a reliable index for the estimation of the individual extent of CV damage. On the other side, the group with moderate hippocampal atrophy showed the highest increase of alpha2 and alpha3 power. Moreover, when the amygdalar and hippocampal volumes are separately considered, within amygdalohippocampal complex (AHC), the increase of theta/gamma ratio is best associated with amygdalar atrophy whereas alpha3/alpha2 ratio is best associated with hippocampal atrophy. CVD and AHC damages are associated with specific EEG markers. So far, these EEG markers could have a prospective value in differential diagnosis between vascular and degenerative MCI. 1. Introduction Mild cognitive impairment (MCI) is a clinical state intermediate between elderly normal cognition and dementia that affects a significant amount of the elderly population, featuring memory complaints and cognitive impairment on neuropsychological testing, but no dementia [1¨C3]. The hippocampus is one of the first and most affected brain regions impacted by both Alzheimer¡¯s disease and mild cognitive impairment (MCI; [4¨C9]). In mild-to-moderate Alzheimer¡¯s disease patients, it has been shown that hippocampal volumes are 27% smaller than in normal elderly controls [10, 11], whereas patients with MCI show a volume reduction of 11% [11]. So far, from a neuropathological point of view, the progression of disease from MCI state to later stages seems to follow a linear course. Nevertheless, there is some evidence from functional [12¨C14] and biochemical studies [15] that the process of conversion from nondemented to clinically evident demented state is not so linear. Recent fMRI studies have suggested increased medial temporal lobe (MTL) activations in MCI subjects versus controls, during the performance of memory tasks [16, 17]. Nonetheless, fMRI findings in MCI are discrepant, as MTL hypoactivation similar to that seen in AD patients
%U http://www.hindawi.com/journals/ijad/2012/917537/