title: EEG functional network topology is associated with disability in patients with amyotrophic lateral sclerosis.
abstract: Amyotrophic Lateral Sclerosis (ALS) is one of the most severe neurodegenerative diseases, which is known to affect upper and lower motor neurons. In contrast to the classical tenet that ALS represents the outcome of extensive and progressive impairment of a fixed set of motor connections, recent neuroimaging findings suggest that the disease spreads along vast non-motor connections. Here, we hypothesised that functional network topology is perturbed in ALS, and that this reorganization is associated with disability. We tested this hypothesis in 21 patients affected by ALS at several stages of impairment using resting-state electroencephalography (EEG) and compared the results to 16 age-matched healthy controls. We estimated functional connectivity using the Phase Lag Index (PLI), and characterized the network topology using the minimum spanning tree (MST). We found a significant difference between groups in terms of MST dissimilarity and MST leaf fraction in the beta band. Moreover, some MST parameters (leaf, hierarchy and kappa) significantly correlated with disability. These findings suggest that the topology of resting-state functional networks in ALS is affected by the disease in relation to disability. EEG network analysis may be of help in monitoring and evaluating the clinical status of ALS patients.
authors.affiliation: Department of Electrical and Electronic Engineering, University of Cagliari, Piazza D'armi, Cagliari, 09123, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Fraschini
authors.affiliation: Department of Clinical Neurophysiology and MEG Center, VU University Medical Centre, Amsterdam, The Netherlands.
authors.forename: Matteo
authors.initials: M
authors.lastname: Demuru
authors.affiliation: Department of Clinical Neurophysiology and MEG Center, VU University Medical Centre, Amsterdam, The Netherlands.
authors.forename: Arjan
authors.initials: A
authors.lastname: Hillebrand
authors.affiliation: Biomedical Engineering Course, University of Cagliari, Piazza D'armi, Cagliari, 09123, Italy.
authors.forename: Lorenza
authors.initials: L
authors.lastname: Cuccu
authors.affiliation: Department of Neurology, AOU Cagliari, University of Cagliari, Cagliari, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Porcu
authors.affiliation: Department of Neurology, AOU Cagliari, University of Cagliari, Cagliari, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Di Stefano
authors.affiliation: Department of Neurology, AOU Cagliari, University of Cagliari, Cagliari, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Puligheddu
authors.affiliation: Department of Neurology, AOU Cagliari, University of Cagliari, Cagliari, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Floris
authors.affiliation: Department of Neurology, AOU Cagliari, University of Cagliari, Cagliari, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Borghero
authors.affiliation: Department of Neurology, AOU Cagliari, University of Cagliari, Cagliari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Marrosu
mesh_terms: D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D006233:Persons with Disabilities; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons; D009434:Neural Pathways / Q000503:physiopathology; D011379:Prognosis; D012720:Severity of Illness Index