title: Increasing hippocampal atrophy and cerebrovascular damage is differently associated with functional cortical coupling in MCI patients.
abstract: The aim of this study was to assess the changes of intrahemispheric and interhemispheric linear spectral electroencephalography (EEG) coherence associated with increasing hippocampal atrophy (HA) and white matter hyperintensities (WMHs) in patients with mild cognitive impairment (MCI). Eighty-five MCI patients underwent clinical and neuropsychologic assessment, EEG recordings, and magnetic resonance imaging. Intrahemispheric (fronto-temporal, temporo-parietal, and fronto-parietal) and interhemispheric (frontal, temporal, and parietal) linear EEG coherence was computed. MCI patients were categorized into classes of increasing HA and WMHs on the basis of tertile distribution of volume loss (high, mid, and low). Neuropsychologic tests were also gathered and compared in MCI subgroups. As expected, MCI patients with high WMHs had poorer performance on visuospatial and cognitive flexibility, whereas those with high HA failed on memory tests. Significant differences of EEG functional coupling were present in the fronto-temporal network in patients with high WMHs and high HA, but without a different pattern. In high WMHs the EEG coherence in low frequencies was increased (with the exception of alpha1 band), whereas coherence in the fast frequencies was decreased proportional to increasing damage. In high HA a change of coherence was present in the delta and alpha2 frequency bands that was not proportional to HA, fast frequencies being unaffected. Our results show a lateralization (right hemisphere for cerebrovascular disease and left hemisphere for hippocampal atrophy) of the pathologic modifications of functional coupling.
authors: IRCCS S Giovanni di Dio Fatebenefratelli, Brescia, Italy. davide.moretti@afar.it
authors: Davide Vito
authors: DV
authors: Moretti
authors: Michela
authors: M
authors: Pievani
authors: Cristina
authors: C
authors: Geroldi
authors: Giuliano
authors: G
authors: Binetti
authors: Orazio
authors: O
authors: Zanetti
authors: Maria
authors: M
authors: Cotelli
authors: Paolo M
authors: PM
authors: Rossini
authors: Giovanni B
authors: GB
authors: Frisoni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001284:Atrophy / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000473:pathology* / Q000503:physiopathology; D003072:Cognition Disorders / Q000473:pathology* / Q000503:physiopathology; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011597:Psychomotor Performance / Q000502:physiology