title: The behavioral significance of coherent resting-state oscillations after stroke.
abstract: Stroke lesions induce not only loss of local neural function, but disruptions in spatially distributed areas. However, it is unknown whether they affect the synchrony of electrical oscillations in neural networks and if changes in network coherence are associated with neurological deficits. This study assessed these questions in a population of patients with subacute, unilateral, ischemic stroke. Spontaneous cortical oscillations were reconstructed from high-resolution electroencephalograms (EEG) with adaptive spatial filters. Maps of functional connectivity (FC) between brain areas were created and correlated with patient performance in motor and cognitive scores. In comparison to age matched healthy controls, stroke patients showed a selective disruption of FC in the alpha frequency range. The spatial distribution of alpha band FC reflected the pattern of motor and cognitive deficits of the individual patient: network nodes that participate normally in the affected functions showed local decreases in FC with the rest of the brain. Interregional FC in the alpha band, but not in delta, theta, or beta frequencies, was highly correlated with motor and cognitive performance. In contrast, FC between contralesional areas and the rest of the brain was negatively associated with patient performance. Alpha oscillation synchrony at rest is a unique and specific marker of network function and linearly associated with behavioral performance. Maps of alpha synchrony computed from a single resting-state EEG recording provide a robust and convenient window into the functionality and organization of cortical networks with numerous potential applications.
authors.affiliation: Division of Neurorehabilitation, University Hospital of Geneva, Switzerland.
authors.forename: Sviatlana
authors.initials: S
authors.lastname: Dubovik
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Pignat
authors.forename: Radek
authors.initials: R
authors.lastname: Ptak
authors.forename: Tatiana
authors.initials: T
authors.lastname: Aboulafia
authors.forename: Lara
authors.initials: L
authors.lastname: Allet
authors.forename: Nicole
authors.initials: N
authors.lastname: Gillabert
authors.forename: Cécile
authors.initials: C
authors.lastname: Magnin
authors.forename: Fabien
authors.initials: F
authors.lastname: Albert
authors.forename: Isabelle
authors.initials: I
authors.lastname: Momjian-Mayor
authors.forename: Louis
authors.initials: L
authors.lastname: Nahum
authors.forename: Agustina M
authors.initials: AM
authors.lastname: Lascano
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Michel
authors.forename: Armin
authors.initials: A
authors.lastname: Schnider
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Guggisberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000513:Alpha Rhythm / Q000502:physiology; D001288:Attention / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology; D009434:Neural Pathways / Q000503:physiopathology; D020521:Stroke / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D014705:Verbal Behavior / Q000502:physiology