title: Is there a cognitive signature for MS-related fatigue?
abstract: The compensatory approach of fatigue argues that it is a state caused by task load. The neuropsychiatric approach argues that fatigue is a trait (like depression), unrelated to environmental challenges. We propose that fatigue is an internal state that can be measured behaviorally only by applying specific cognitive tasks. PubMed was searched for articles concerning the relation between fatigue and cognitive performance or brain atrophy or functional MRI, distinguishing between the following cognitive domains: learning/memory, cognitive speed/selective attention, language, visuospatial processing, working memory, alerting/vigilance. Only tasks assessing alerting/vigilance are strongly related to fatigue. Areas with brain atrophy in fatigue patients overlap with brain regions activated in healthy controls performing alerting/vigilance tasks. Fatigue is not a compensatory state, nor a psychogenic trait. It is a feeling with behavioral effects that seems to be caused by brain atrophy or a neurochemical dysfunction of the alerting/vigilance system.
authors.affiliation: Klinikum Bremen-Ost, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Hanken
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, the Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Eling
authors.affiliation: Klinikum Bremen-Ost, Germany/University of Oldenburg, Institute of Psychology, Germany helmut-hildebrandt@uni-oldenburg.de.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hildebrandt
mesh_terms: D001284:Atrophy / Q000473:pathology; D001288:Attention / Q000502:physiology; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D003071:Cognition / Q000502:physiology; D005221:Fatigue / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology*; D006801:Humans; D009103:Multiple Sclerosis / Q000150:complications* / Q000473:pathology / Q000523:psychology*
keywords: Multiple sclerosis; attentional systems; brain atrophy; cognitive testing; fatigue; neuronal networks of attention; vigilance