TY - JOUR
T1 - “Small World” architecture in brain connectivity and hippocampal volume in Alzheimer’s disease: a study via graph theory from EEG data
AU - Vecchio, Fabrizio
AU - Miraglia, Francesca
AU - Piludu, Francesca
AU - Granata, Giuseppe
AU - Romanello, Roberto
AU - Caulo, Massimo
AU - Onofrj, Valeria
AU - Bramanti, Placido
AU - Colosimo, Cesare
AU - Rossini, Paolo Maria
PY - 2017
Y1 - 2017
N2 - Brain imaging plays an important role in the study of Alzheimer’s disease (AD), where atrophy has been found to occur in the hippocampal formation during the very early disease stages and to progress in parallel with the disease’s evolution. The aim of the present study was to evaluate a possible correlation between “Small World” characteristics of the brain connectivity architecture—as extracted from EEG recordings—and hippocampal volume in AD patients. A dataset of 144 subjects, including 110 AD (MMSE 21.3) and 34 healthy Nold (MMSE 29.8) individuals, was evaluated. Weighted and undirected networks were built by the eLORETA solutions of the cortical sources’ activities moving from EEG recordings. The evaluation of the hippocampal volume was carried out on a subgroup of 60 AD patients who received a high-resolution T1-weighted sequence and underwent processing for surface-based cortex reconstruction and volumetric segmentation using the Freesurfer image analysis software. Results showed that, quantitatively, more correlation was observed in the right hemisphere, but the same trend was seen in both hemispheres. Alpha band connectivity was negatively correlated, while slow (delta) and fast-frequency (beta, gamma) bands positively correlated with hippocampal volume. Namely, the larger the hippocampal volume, the lower the alpha and the higher the delta, beta, and gamma Small World characteristics of connectivity. Accordingly, the Small World connectivity pattern could represent a functional counterpart of structural hippocampal atrophying and related-network disconnection.
AB - Brain imaging plays an important role in the study of Alzheimer’s disease (AD), where atrophy has been found to occur in the hippocampal formation during the very early disease stages and to progress in parallel with the disease’s evolution. The aim of the present study was to evaluate a possible correlation between “Small World” characteristics of the brain connectivity architecture—as extracted from EEG recordings—and hippocampal volume in AD patients. A dataset of 144 subjects, including 110 AD (MMSE 21.3) and 34 healthy Nold (MMSE 29.8) individuals, was evaluated. Weighted and undirected networks were built by the eLORETA solutions of the cortical sources’ activities moving from EEG recordings. The evaluation of the hippocampal volume was carried out on a subgroup of 60 AD patients who received a high-resolution T1-weighted sequence and underwent processing for surface-based cortex reconstruction and volumetric segmentation using the Freesurfer image analysis software. Results showed that, quantitatively, more correlation was observed in the right hemisphere, but the same trend was seen in both hemispheres. Alpha band connectivity was negatively correlated, while slow (delta) and fast-frequency (beta, gamma) bands positively correlated with hippocampal volume. Namely, the larger the hippocampal volume, the lower the alpha and the higher the delta, beta, and gamma Small World characteristics of connectivity. Accordingly, the Small World connectivity pattern could represent a functional counterpart of structural hippocampal atrophying and related-network disconnection.
KW - Alzheimer
KW - Behavioral Neuroscience
KW - Cellular and Molecular Neuroscience
KW - Cognitive Neuroscience
KW - EEG
KW - Functional connectivity
KW - Graph theory
KW - Hippocampus
KW - MRI
KW - Neurology
KW - Neurology (clinical)
KW - Psychiatry and Mental Health
KW - Radiology, Nuclear Medicine and Imaging
KW - eLORETA
KW - Alzheimer
KW - Behavioral Neuroscience
KW - Cellular and Molecular Neuroscience
KW - Cognitive Neuroscience
KW - EEG
KW - Functional connectivity
KW - Graph theory
KW - Hippocampus
KW - MRI
KW - Neurology
KW - Neurology (clinical)
KW - Psychiatry and Mental Health
KW - Radiology, Nuclear Medicine and Imaging
KW - eLORETA
UR - http://hdl.handle.net/10807/92803
UR - http://www.springer.com/east/home?sgwid=5-102-70-173667707-0&changeheader=true
U2 - 10.1007/s11682-016-9528-3
DO - 10.1007/s11682-016-9528-3
M3 - Article
SN - 1931-7557
VL - 11
SP - 473
EP - 485
JO - Brain Imaging and Behavior
JF - Brain Imaging and Behavior
ER -