A Pilot Study Investigating a Novel Non-Linear Measure of Eyes Open versus Eyes Closed EEG Synchronization in People with Alzheimer’s Disease and Healthy Controls
by
Daniel J. Blackburn 1,*
, Yifan Zhao 2, Matteo De Marco 1, Simon M. Bell 1, Fei He 3, Hua-Liang Wei 4, Sarah Lawrence 5, Zoe C. Unwin 5, Michelle Blyth 5, Jenna Angel 5, Kathleen Baster 6, Thomas F. D. Farrow 1, Iain D. Wilkinson 7, Stephen A. Billings 4, Annalena Venneri 1 and Ptolemaios G. Sarrigiannis 5
Daniel J. Blackburn 1,*, Yifan Zhao 2, Matteo De Marco 1, Simon M. Bell 1, Fei He 3, Hua-Liang Wei 4, Sarah Lawrence 5, Zoe C. Unwin 5, Michelle Blyth 5, Jenna Angel 5, Kathleen Baster 6, Thomas F. D. Farrow 1, Iain D. Wilkinson 7, Stephen A. Billings 4, Annalena Venneri 1 and Ptolemaios G. Sarrigiannis 5
1
Department of Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
2
Department of Clinical Neurophysiology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S10 2JF, UK
3
School of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield MK43, UK
4
School of Mathematics & Statistics, University of Sheffield, Sheffield S1 2TN, UK
5
Academic Unit of Radiology, University of Sheffield, Sheffield S1 2TN, UK
6
Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7, UK
7
Department of Automatic Control & Systems Engineering, University of Sheffield, Sheffield S10 2TN, UK
*
Author to whom correspondence should be addressed.
Brain Sci. 2018, 8(7), 134; https://doi.org/10.3390/brainsci8070134
Received: 29 May 2018 / Revised: 27 June 2018 / Accepted: 16 July 2018 / Published: 17 July 2018
Background: The incidence of Alzheimer disease (AD) is increasing with the ageing population. The development of low cost non-invasive diagnostic aids for AD is a research priority. This pilot study investigated whether an approach based on a novel dynamic quantitative parametric EEG method could detect abnormalities in people with AD. Methods: 20 patients with probable AD, 20 matched healthy controls (HC) and 4 patients with probable fronto temporal dementia (FTD) were included. All had detailed neuropsychology along with structural, resting state fMRI and EEG. EEG data were analyzed using the Error Reduction Ratio-causality (ERR-causality) test that can capture both linear and nonlinear interactions between different EEG recording areas. The 95% confidence intervals of EEG levels of bi-centroparietal synchronization were estimated for eyes open (EO) and eyes closed (EC) states. Results: In the EC state, AD patients and HC had very similar levels of bi-centro parietal synchronization; but in the EO resting state, patients with AD had significantly higher levels of synchronization (AD = 0.44; interquartile range (IQR) 0.41 vs. HC = 0.15; IQR 0.17, p < 0.0001). The EO/EC synchronization ratio, a measure of the dynamic changes between the two states, also showed significant differences between these two groups (AD ratio 0.78 versus HC ratio 0.37 p < 0.0001). EO synchronization was also significantly different between AD and FTD (FTD = 0.075; IQR 0.03, p < 0.0001). However, the EO/EC ratio was not informative in the FTD group due to very low levels of synchronization in both states (EO and EC). Conclusion: In this pilot work, resting state quantitative EEG shows significant differences between healthy controls and patients with AD. This approach has the potential to develop into a useful non-invasive and economical diagnostic aid in AD.
View Full-Text
Keywords:
Alzheimer’s disease; electroencephalography; clinical marker; ROC curve; nonlinear dynamics
▼
Show Figures
Figure 1
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
MDPI and ACS Style
Blackburn, D.J.; Zhao, Y.; De Marco, M.; Bell, S.M.; He, F.; Wei, H.-L.; Lawrence, S.; Unwin, Z.C.; Blyth, M.; Angel, J.; Baster, K.; Farrow, T.F.D.; Wilkinson, I.D.; Billings, S.A.; Venneri, A.; Sarrigiannis, P.G. A Pilot Study Investigating a Novel Non-Linear Measure of Eyes Open versus Eyes Closed EEG Synchronization in People with Alzheimer’s Disease and Healthy Controls. Brain Sci. 2018, 8, 134.
Show more citation formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
