title: Functional connectivity disruptions correlate with cognitive phenotypes in Parkinson's disease.
abstract: Cognitive deficits in Parkinson's disease are thought to be related to altered functional brain connectivity. To date, cognitive-related changes in Parkinson's disease have never been explored with dense-EEG with the aim of establishing a relationship between the degree of cognitive impairment, on the one hand, and alterations in the functional connectivity of brain networks, on the other hand. This study was aimed at identifying altered brain networks associated with cognitive phenotypes in Parkinson's disease using dense-EEG data recorded during rest with eyes closed. Three groups of Parkinson's disease patients (N = 124) with different cognitive phenotypes coming from a data-driven cluster analysis, were studied: G1) cognitively intact patients (63), G2) patients with mild cognitive deficits (46) and G3) patients with severe cognitive deficits (15). Functional brain networks were identified using a dense-EEG source connectivity method. Pairwise functional connectivity was computed for 68 brain regions in different EEG frequency bands. Network statistics were assessed at both global (network topology) and local (inter-regional connections) level. Results revealed progressive disruptions in functional connectivity between the three patient groups, typically in the alpha band. Differences between G1 and G2 (p< 0.001, corrected using permutation test) were mainly frontotemporal alterations. A statistically significant correlation (ρ = 0.49,p< 0.001) was also obtained between a proposed network-based index and the patients' cognitive score. Global properties of network topology in patients were relatively intact. These findings indicate that functional connectivity decreases with the worsening of cognitive performance and loss of frontotemporal connectivity may be a promising neuromarker of cognitive impairment in Parkinson's disease.
authors.affiliation: INSERM, U1099, F-35000 Rennes, France; University of Rennes 1, LTSI, F-35000 Rennes, France.
authors.forename: M
authors.initials: M
authors.lastname: Hassan
authors.affiliation: CHU Lille, Clinical Neurophysiology Department, F-59000 Lille, France.
authors.forename: L
authors.initials: L
authors.lastname: Chaton
authors.affiliation: INSERM, U1099, F-35000 Rennes, France; University of Rennes 1, LTSI, F-35000 Rennes, France.
authors.forename: P
authors.initials: P
authors.lastname: Benquet
authors.affiliation: University of Lille, U1171 - Degenerative & Vascular Cognitive Disorders, F-59000 Lille, France; INSERM, U1171, F-59000 Lille, France; CHU Lille, Clinical Neurophysiology Department, F-59000 Lille, France.
authors.forename: A
authors.initials: A
authors.lastname: Delval
authors.affiliation: University of Lille, U1171 - Degenerative & Vascular Cognitive Disorders, F-59000 Lille, France; INSERM, U1171, F-59000 Lille, France; CHU Lille, Clinical Neurophysiology Department, F-59000 Lille, France.
authors.forename: C
authors.initials: C
authors.lastname: Leroy
authors.affiliation: University of Lille, U1171 - Degenerative & Vascular Cognitive Disorders, F-59000 Lille, France; INSERM, U1171, F-59000 Lille, France; CHU Lille, Clinical Neurophysiology Department, F-59000 Lille, France.
authors.forename: L
authors.initials: L
authors.lastname: Plomhause
authors.affiliation: Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: A J H
authors.initials: AJ
authors.lastname: Moonen
authors.affiliation: Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: A A
authors.initials: AA
authors.lastname: Duits
authors.affiliation: Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: A F G
authors.initials: AF
authors.lastname: Leentjens
authors.affiliation: Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: V
authors.initials: V
authors.lastname: van Kranen-Mastenbroek
authors.affiliation: University of Lille, U1171 - Degenerative & Vascular Cognitive Disorders, F-59000 Lille, France; INSERM, U1171, F-59000 Lille, France; CHU Lille, Neurology and Movement Disorders Department, F-59000 Lille, France.
authors.forename: L
authors.initials: L
authors.lastname: Defebvre
authors.affiliation: University of Lille, U1171 - Degenerative & Vascular Cognitive Disorders, F-59000 Lille, France; INSERM, U1171, F-59000 Lille, France; CHU Lille, Clinical Neurophysiology Department, F-59000 Lille, France.
authors.forename: P
authors.initials: P
authors.lastname: Derambure
authors.affiliation: INSERM, U1099, F-35000 Rennes, France; University of Rennes 1, LTSI, F-35000 Rennes, France.
authors.forename: F
authors.initials: F
authors.lastname: Wendling
authors.affiliation: University of Lille, U1171 - Degenerative & Vascular Cognitive Disorders, F-59000 Lille, France; INSERM, U1171, F-59000 Lille, France; CHU Lille, Neurology and Movement Disorders Department, F-59000 Lille, France.
authors.forename: K
authors.initials: K
authors.lastname: Dujardin
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology*; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology*; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D013057:Spectrum Analysis; D013223:Statistics as Topic
keywords: Brain connectivity; Cognitive deficits; Dense electroencephalography; Network measures; Parkinson's disease