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Behavioural Neurology
Volume 26, Issue 3, Pages 187-189

EEG Alpha Band Synchrony Predicts Cognitive and Motor Performance in Patients with Ischemic Stroke

Sviatlana Dubovik,1 Radek Ptak,1 Tatiana Aboulafia,2 Cécile Magnin,1 Nicole Gillabert,1 Lara Allet,1 Jean-Michel Pignat,2 Armin Schnider,1 and Adrian G. Guggisberg1

1Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland
2Division of Neurology, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland

Received 21 May 2012; Accepted 21 May 2012

Copyright © 2013 Hindawi Publishing Corporation and the authors. 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.


Functional brain networks are known to be affected by focal brain lesions. However, the clinical relevance of these changes remains unclear. This study assesses resting-state functional connectivity (FC) with electroencephalography (EEG) and relates observed topography of FC to cognitive and motor deficits in patients three months after ischemic stroke. Twenty patients (mean age 61.3 years, range 37–80, 9 females) and nineteen age-matched healthy participants (mean age 66.7 years, range 36–88, 13 females) underwent a ten-minute EEG-resting state examination. The neural oscillations at each grey matter voxel were reconstructed using an adaptive spatial filter and imaginary component of coherence (IC) was calculated as an index of FC. Maps representing mean connectivity value at each voxel were correlated with the clinical data. Compared to healthy controls, alpha band IC of stroke patients was locally reduced in brain regions critical to observed behavioral deficits. A voxel-wise Pearson correlation of clinical performances with FC yielded maps of the neural structures implicated in motor, language, and executive function. This correlation was again specific to alpha band coherence. Ischemic lesions decrease the synchrony of alpha band oscillations between affected brain regions and the rest of the brain. This decrease is linearly related to cognitive and motor deficits observed in the patients.