title: Neurophysiological Evidence of Compensatory Brain Mechanisms in Early-Stage Multiple Sclerosis.
abstract: Multiple sclerosis (MS) is a chronic central nervous system disorder characterized by white matter inflammation, demyelination and neurodegeneration. Although cognitive dysfunction is a common manifestation, it may go unnoticed in recently-diagnosed patients. Prior studies suggest MS patients develop compensatory mechanisms potentially involving enhanced performance monitoring. Here we assessed the performance monitoring system in early-stage MS patients using the error-related negativity (ERN), an event-related brain potential (ERP) observed following behavioral errors. Twenty-seven early-stage MS patients and 31 controls were neuropsychologically assessed. Electroencephalography recordings were obtained while participants performed: a) a stop task and b) an auditory oddball task. Behavior and ERP measures were assessed. No differences in performance were found between groups in most neuropsychological tests or in behavior or ERP components in the auditory oddball task. However, the amplitude of the ERN associated with stop errors in the stop task was significantly higher in patients. ERN amplitude correlated positively with scores on the Expanded Disability Status Scale and the Multiple Sclerosis Severity Score, and negatively with the time since last relapse. Patients showed higher neuronal recruitment in tasks involving performance monitoring. Results suggest the development of compensatory brain mechanisms in early-stage MS and reflect the sensitivity of the ERN to detect these changes.
authors: Multiple Sclerosis Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Medicina, Universitat Autónoma de Barcelona, Barcelona, Spain; Multiple Sclerosis Research Group, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain.
authors: Mariana
authors: M
authors: López-Góngora
authors: Multiple Sclerosis Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Medicina, Universitat Autónoma de Barcelona, Barcelona, Spain; Multiple Sclerosis Research Group, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain.
authors: Antonio
authors: A
authors: Escartín
authors: Movement Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Parkinson's Disease and Movement Disorders Research Group, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain.
authors: Saul
authors: S
authors: Martínez-Horta
authors: Movement Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Parkinson's Disease and Movement Disorders Research Group, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain.
authors: Ramón
authors: R
authors: Fernández-Bobadilla
authors: Multiple Sclerosis Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Multiple Sclerosis Research Group, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain.
authors: Luis
authors: L
authors: Querol
authors: Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB), Universitat Politècnica de Catalunya, BarcelonaTech (UPC), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain.
authors: Sergio
authors: S
authors: Romero
authors: Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB), Universitat Politècnica de Catalunya, BarcelonaTech (UPC), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain.
authors: Miquel Àngel
authors: MÀ
authors: Mañanas
authors: Human Neuropsychopharmacology Group, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain; Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Barcelona, Spain.
authors: Jordi
authors: J
authors: Riba
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000503:physiopathology; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000503:physiopathology* / Q000523:psychology*; D064926:Neurophysiological Monitoring; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*