title: Normalization of aberrant resting state functional connectivity in fibromyalgia patients following a three month physical exercise therapy.
abstract: Physical exercise is one of the most efficient interventions to mitigate chronic pain symptoms in fibromyalgia (FM). However, little is known about the neurophysiological mechanisms mediating these effects. In this study we investigated resting-state connectivity using functional magnetic resonance imaging (fMRI) before and after a 15 week standardized exercise program supervised by physical therapists. Our aim was to gain an understanding of how physical exercise influences previously shown aberrant patterns of intrinsic brain activity in FM. Fourteen FM patients and eleven healthy controls successfully completed the physical exercise treatment. We investigated post- versus pre-treatment changes of brain connectivity, as well as changes in clinical symptoms in the patient group. FM patients reported improvements in symptom severity. Although several brain regions showed a treatment-related change in connectivity, only the connectivity between the right anterior insula and the left primary sensorimotor area was significantly more affected by the physical exercise among the fibromyalgia patients compared to healthy controls. Our results suggest that previously observed aberrant intrinsic brain connectivity patterns in FM are partly normalized by the physical exercise therapy. However, none of the observed normalizations in intrinsic brain connectivity were significantly correlated with symptom changes. Further studies conducted in larger cohorts are warranted to investigate the precise relationship between improvements in fibromyalgia symptoms and changes in intrinsic brain activity.
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Flodin
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Martinsen
authors.affiliation: Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Mannerkorpi
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Löfgren
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: I
authors.initials: I
authors.lastname: Bileviciute-Ljungar
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Kosek
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Fransson
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D005081:Exercise Therapy; D005260:Female; D005356:Fibromyalgia / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D066191:Sensorimotor Cortex / Q000503:physiopathology
keywords: FIQ, Fibromyalgia Impact Questionnaire; FM, fibromyalgia; Fibromyalgia; Functional connectivity; PAG, periaqueductal grey; Physical exercise; Resting state fMRI; SF36BP, bodily pain subscale of the Short Form Health Survey