title: White-matter lesions along the cholinergic tracts are related to cortical sources of EEG rhythms in amnesic mild cognitive impairment.
abstract: Does impairment of cholinergic systems represent an important factor in the development of amnesic mild cognitive impairment (aMCI), as a preclinical stage of Alzheimer's disease (AD)? Here we tested the hypothesis that electroencephalographic (EEG) rhythms, known to be modulated by the cholinergic system, may be particularly affected in aMCI patients with lesions along the cholinergic white-matter tracts. Eyes-closed resting EEG data were recorded in 28 healthy elderly (Nold) and 57 aMCI patients. Lesions along the cholinergic white-matter tracts were detected with fluid-attenuated inversion recovery sequences on magnetic resonance imaging. The estimation of the cholinergic lesion was performed with a validated semi-automatic algorithm pipeline after registration to a stereotactic template, image integration with stereotactic masks of the cholinergic tracts, and normalization to intracranial volume. The aMCI patients were divided into two groups of high (MCI Ch+; N = 29; MMSE = 26.2) and low cholinergic damage (MCI Ch-; N = 28; MMSE = 26.6). EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). Cortical EEG generators were estimated by LORETA software. As main results, (i) power of occipital, parietal, temporal, and limbic alpha 1 sources was maximum in Nold, intermediate in MCI Ch-, and low in MCI Ch+ patients; (ii) the same trend was true in theta sources. These results are consistent with the hypothesis that damage to the cholinergic system is associated with alterations of EEG sources in aMCI subjects.
authors.affiliation: Department of Biomedical Sciences, University of Foggia, Foggia, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Babiloni
authors.forename: Michela
authors.initials: M
authors.lastname: Pievani
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Vecchio
authors.forename: Cristina
authors.initials: C
authors.lastname: Geroldi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Eusebi
authors.forename: Claudia
authors.initials: C
authors.lastname: Fracassi
authors.forename: Evan
authors.initials: E
authors.lastname: Fletcher
authors.forename: Charles
authors.initials: C
authors.lastname: De Carli
authors.forename: Marina
authors.initials: M
authors.lastname: Boccardi
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Rossini
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Frisoni
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000368:Aged; D000513:Alpha Rhythm; D000647:Amnesia / Q000150:complications / Q000473:pathology*; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000293:injuries / Q000473:pathology / Q000503:physiopathology; D003072:Cognition Disorders / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000473:pathology; D009483:Neuropsychological Tests; D013057:Spectrum Analysis
chemical_list: D000109:Acetylcholine