title: Sensorimotor cortex excitability and connectivity in Alzheimer's disease: A TMS-EEG Co-registration study.
abstract: Several studies have shown that, in spite of the fact that motor symptoms manifest late in the course of Alzheimer's disease (AD), neuropathological progression in the motor cortex parallels that in other brain areas generally considered more specific targets of the neurodegenerative process. It has been suggested that motor cortex excitability is enhanced in AD from the early stages, and that this is related to disease's severity and progression. To investigate the neurophysiological hallmarks of motor cortex functionality in early AD we combined transcranial magnetic stimulation (TMS) with electroencephalography (EEG). We demonstrated that in mild AD the sensorimotor system is hyperexcitable, despite the lack of clinically evident motor manifestations. This phenomenon causes a stronger response to stimulation in a specific time window, possibly due to locally acting reinforcing circuits, while network activity and connectivity is reduced. These changes could be interpreted as a compensatory mechanism allowing for the preservation of sensorimotor programming and execution over a long period of time, regardless of the disease's progression. Hum Brain Mapp 37:2083-2096, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Neurology, University Campus Biomedico, Rome, Italy.|Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
authors.forename: Florinda
authors.initials: F
authors.lastname: Ferreri
authors.affiliation: Brain Connectivity Laboratory, IRCCS S. Raffaele-Pisana, Rome, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Vecchio
authors.affiliation: Department of Computer Science and Computer Engineering, University Campus Bio-Medico, Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Vollero
authors.affiliation: Department of Neurology, University Campus Biomedico, Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Guerra
authors.affiliation: Department of Computer Science and Computer Engineering, University Campus Bio-Medico, Rome, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Petrichella
authors.affiliation: Department of Neurology, University Campus Biomedico, Rome, Italy.|Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
authors.forename: David
authors.initials: D
authors.lastname: Ponzo
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
authors.forename: Sara
authors.initials: S
authors.lastname: Määtta
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
authors.forename: Esa
authors.initials: E
authors.lastname: Mervaala
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.|Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Mervi
authors.initials: M
authors.lastname: Könönen
authors.affiliation: Department of Neurology, University Campus Biomedico, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ursini
authors.affiliation: Brain Connectivity Laboratory, IRCCS S. Raffaele-Pisana, Rome, Italy.|AFaR Division, Service of Medical Statistics and Information Technology, Fatebenefratelli Foundation for Health Research and Education, Rome, Italy.
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pasqualetti
authors.affiliation: Department of Computer Science and Computer Engineering, University Campus Bio-Medico, Rome, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Iannello
authors.affiliation: Brain Connectivity Laboratory, IRCCS S. Raffaele-Pisana, Rome, Italy.|Institute of Neurology, Department of Geriatrics, Neurosciences, Orthopaedics, Policlinic a. Gemelli, Catholic University, Rome, Italy.
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Rossini
authors.affiliation: Department of Neurology, University Campus Biomedico, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Di Lazzaro
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology; D066191:Sensorimotor Cortex / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D050781:Transcranial Magnetic Stimulation / Q000379:methods
keywords: Alzheimer's disease; EEG; navigated transcranial magnetic stimulation; sensorimotor cortex connectivity; sensorimotor cortex excitability