University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Complexity changes in preclinical Alzheimer’s disease: An MEG study of subjective cognitive decline and mild cognitive impairment

Shumbayawonda, Elizabeth, López-Sanz, David, Bruña, Ricardo, Serrano, Noelia, Fernández, Alberto, Maestú, Fernando and Abasolo, Daniel (2020) Complexity changes in preclinical Alzheimer’s disease: An MEG study of subjective cognitive decline and mild cognitive impairment Clinical Neurophysiology, 131 (2). pp. 437-445.

Shumbayawonda_et_al_ClinNeurophysiol_final_version_2019.pdf - Accepted version Manuscript

Download (473kB) | Preview



To analyse magnetoencephalogram (MEG) signals with Lempel-Ziv Complexity (LZC) to identify the regions of the brain showing changes related to cognitive decline and Alzheimeŕs Disease (AD).


LZC was used to study MEG signals in the source space from 99 participants (36 male, 63 female, average age: 71.82 ± 4.06) in three groups (33 subjects per group): healthy (control) older adults, older adults with subjective cognitive decline (SCD), and adults with mild cognitive impairment (MCI). Analyses were performed in broadband (2–45 Hz) and in classic narrow bands (theta (4–8 Hz), alpha (8–12 Hz), low beta (12–20 Hz), high beta (20–30 Hz), and, gamma (30–45 Hz)).


LZC was significantly lower in subjects with MCI than in those with SCD. Moreover, subjects with MCI had significantly lower MEG complexity than controls and SCD subjects in the beta frequency band. Lower complexity was correlated with smaller hippocampal volumes.


Brain complexity – measured with LZC – decreases in MCI patients when compared to SCD and healthy controls. This decrease is associated with a decrease in hippocampal volume, a key feature in AD progression.


This is the first study to date characterising the changes of brain activity complexity showing the specific spatial pattern of the alterations as well as the morphological correlations throughout preclinical stages of AD.

Item Type: Article
Divisions : Faculty of Engineering and Physical Sciences > Mechanical Engineering Sciences
Authors :
López-Sanz, David
Bruña, Ricardo
Serrano, Noelia
Fernández, Alberto
Maestú, Fernando
Date : February 2020
DOI : 10.1016/j.clinph.2019.11.023
Copyright Disclaimer : Copyright 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved
Uncontrolled Keywords : Lempel-Ziv complexity; Magnetoencephalogram; Subjective cognitive decline; Mild cognitive impairment; Source space; Alzheimer’s disease
Additional Information : This study was supported by a project from the Spanish Ministry of Economy and Competitiveness, PSI2009-14415-C03-01 and a project by Comunidad de Madrid, B2017/BMD-3760 (NEUROCENTRO-CM). Elizabeth Shumbayawonda was supported by a Santander Universities Postgraduate Research Award.
Depositing User : Diane Maxfield
Date Deposited : 17 Jan 2020 11:10
Last Modified : 07 Dec 2020 02:08

Actions (login required)

View Item View Item


Downloads per month over past year

Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800