Cerebral PET glucose hypometabolism in subjects with mild cognitive impairment and higher EEG high-alpha/low-alpha frequency power ratio

• Published in: Neurobiology of aging Vol. 58; pp. 213 - 224
• Main Authors: Moretti, Davide Vito, Pievani, Michela, Pini, Lorenzo, Guerra, Ugo Paolo, Paghera, Barbara, Frisoni, Giovanni Battista
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2017
• Subjects: Aged; Alpha rhythm; Alzheimer Disease - diagnosis; Amyloid beta-Peptides - cerebrospinal fluid; Biomarkers - cerebrospinal fluid; Brain - diagnostic imaging; Brain - metabolism; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - metabolism; CSF; EEG; Electroencephalography; Female; Fluorodeoxyglucose F18; Glucose - metabolism; Humans; Magnetic Resonance Imaging; Male; MCI; Middle Aged; MRI; Neuroimaging; Peptide Fragments - cerebrospinal fluid; PET; Positron-Emission Tomography; Radiopharmaceuticals; tau Proteins - cerebrospinal fluid; Alpha rhythm; MCI; MRI; EEG; PET; CSF
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2017.06.009

In Alzheimer's disease (AD) research, both 2-deoxy-2-(18F)fluoro-D-glucose (FDG) positron emission tomography (PET) and electroencephalography (EEG) are reliable investigational modalities. The aim of this study was to investigate the associations between EEG High-alpha/Low-alpha (H-alpha/L-alpha) power ratio and cortical glucose metabolism. A total of 23 subjects with mild cognitive impairment (MCI) underwent FDG-PET and EEG examinations. H-alpha/L-alpha power ratio was computed for each subject and 2 groups were obtained based on the increase of the power ratio. The subjects with higher H-alpha/L-alpha power ratio showed a decrease in glucose metabolism in the hub brain areas previously identified as typically affected by AD pathology. In subjects with higher H-alpha/L-alpha ratio and lower metabolism, a “double alpha peak” was identified in the EEG spectrum and a U-shaped correlation between glucose metabolism and increase of H-alpha/L-alpha power ratio has been found. Moreover, in this group, a conversion rate of 62.5% at 24 months was detected, significantly different from the chance percentage expected. The neurophysiological meaning of the interplay between alpha oscillations and glucose metabolism and the possible interest of the H-alpha/L-alpha power ratio as a clinical biomarker in AD have been discussed.