58. Cortical sources of resting state EEG rhythms in Alzheimer’s disease patients are related to the integrity of structural brain connectivity as revealed by tractography: An EEG-DTI combined study

Abstract

Alzheimer’s disease (AD) patients show abnormal cortical sources of resting state EEG rhythms, especially at delta (1–4 Hz) and alpha (8–13 Hz) bands. Here we hypothesized that this abnormality is correlated to impaired structural brain connectivity. Eyes closed resting state EEG and structural MRI-DTI (diffusion tensor imaging) data were acquired in 21 AD and in 9 mild cognitive impairment (MCI) patients. LORETA and FSL were used for data analysis. Compared to MCI subjects, AD patients showed a reduction of DTI fractional anisotropy (FA) in several white matter brain bundles (p < 0.05 corrected). Among these bundles, there was a negative correlation in AD patients between delta sources and FA in Forceps minor, left Superior longitudinal fasciculus, and bilateral Inferior longitudinal fasciculus (p < 0.05 corrected). Analogously, there was a positive correlation in AD patients between alpha sources and FA in Forceps minor, right Superior longitudinal, and left Inferior longitudinal fasciculus (p < 0.05 corrected). In AD patients, abnormal cortical sources of delta and alpha rhythms are correlated to the atrophy of structural long-tract brain connectivity. Cortical sources of resting state EEG rhythms in AD patients reflect a neurodegenerative brain disconnection.