AUTHOR=Moretti Davide V., paternicò donata , Binetti Giuliano , Zanetti Orazio , Frisoni giovanni b.

TITLE=EEG upper/low alpha frequency power ratio relates to temporo-parietal brain atrophy and memory performances in mild cognitive impairment

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=5

YEAR=2013

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2013.00063

DOI=10.3389/fnagi.2013.00063

ISSN=1663-4365

ABSTRACT=<p><bold>Objective:</bold> Temporo-parietal cortex thinning is associated to mild cognitive impairment (MCI) due to Alzheimer disease (AD). The increase of EEG upper/low alpha power ratio has been associated with AD-converter MCI subjects. We investigated the association of alpha3/alpha2 ratio with patterns of cortical thickness in MCI.</p><p><bold>Materials and Methods:</bold> Seventy-four adult subjects with MCI underwent clinical and neuropsychological evaluation, electroencephalogram (EEG) recording and high resolution 3D magnetic resonance imaging. Alpha3/alpha2 power ratio as well as cortical thickness was computed for each subject. Three MCI groups were detected according to increasing tertile values of upper/low alpha power ratio. Difference of cortical thickness among the groups was estimated. Pearson’s <italic>r</italic> was used to assess the topography of the correlation between cortical thinning and memory impairment.</p><p><bold>Results:</bold> High upper/low alpha power ratio group had total cortical gray matter volume reduction of 471 mm<sup>2</sup> than low upper/low alpha power ratio group (<italic>p</italic> &lt; 0.001). Upper/low alpha group showed a similar but less marked pattern (160 mm<sup>2</sup>) of cortical thinning when compared to middle upper/low alpha power ratio group (<italic>p</italic> &lt; 0.001). Moreover, high upper/low alpha group had wider cortical thinning than other groups, mapped to the Supramarginal and Precuneus bilaterally. Finally, in high upper/low alpha group temporo-parietal cortical thickness was correlated to memory performance. No significant cortical thickness differences was found between middle and low alpha3/alpha2 power ratio groups.</p><p><bold>Conclusion:</bold> High EEG upper/low alpha power ratio was associated with temporo-parietal cortical thinning and memory impairment in MCI subjects. The combination of EEG upper/low alpha ratio and cortical thickness measure could be useful for identifying individuals at risk for progression to AD dementia and may be of value in clinical context.</p>