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Neural Plasticity
Volume 2016 (2016), Article ID 8376108, 10 pages
http://dx.doi.org/10.1155/2016/8376108
Research Article

Parietal Fast Sleep Spindle Density Decrease in Alzheimer’s Disease and Amnesic Mild Cognitive Impairment

1Department of Psychology, “Sapienza” University of Rome, 00185 Rome, Italy
2Department of Physiology and Pharmacology, “Sapienza” University of Rome, 00185 Rome, Italy
3Department of Biomedical and Clinical Sciences “Luigi Sacco”, University of Milan, 20157 Milan, Italy
4Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy
5Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 Coppito, Italy
6Institute of Neurology, Catholic University of The Sacred Heart, 00168 Rome, Italy
7IRCCS San Raffaele Pisana, 00163 Rome, Italy

Received 21 December 2015; Revised 2 February 2016; Accepted 17 February 2016

Academic Editor: Julie Carrier

Copyright © 2016 Maurizio Gorgoni et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Several studies have identified two types of sleep spindles: fast (13–15 Hz) centroparietal and slow (11–13 Hz) frontal spindles. Alterations in spindle activity have been observed in Alzheimer’s disease (AD) and Mild Cognitive Impairment (MCI). Only few studies have separately assessed fast and slow spindles in these patients showing a reduction of fast spindle count, but the possible local specificity of this phenomenon and its relation to cognitive decline severity are not clear. Moreover, fast and slow spindle density have never been assessed in AD/MCI. We have assessed fast and slow spindles in 15 AD patients, 15 amnesic MCI patients, and 15 healthy elderly controls (HC). Participants underwent baseline polysomnographic recording (19 cortical derivations). Spindles during nonrapid eye movements sleep were automatically detected, and spindle densities of the three groups were compared in the derivations where fast and slow spindles exhibited their maximum expression (parietal and frontal, resp.). AD and MCI patients showed a significant parietal fast spindle density decrease, positively correlated with Minimental State Examination scores. Our results suggest that AD-related changes in spindle density are specific for frequency and location, are related to cognitive decline severity, and may have an early onset in the pathology development.