title: Gray matter alterations in chronic pain: A network-oriented meta-analytic approach.
abstract: Several studies have attempted to characterize morphological brain changes due to chronic pain. Although it has repeatedly been suggested that longstanding pain induces gray matter modifications, there is still some controversy surrounding the direction of the change (increase or decrease in gray matter) and the role of psychological and psychiatric comorbidities. In this study, we propose a novel, network-oriented, meta-analytic approach to characterize morphological changes in chronic pain. We used network decomposition to investigate whether different kinds of chronic pain are associated with a common or specific set of altered networks. Representational similarity techniques, network decomposition and model-based clustering were employed: i) to verify the presence of a core set of brain areas commonly modified by chronic pain; ii) to investigate the involvement of these areas in a large-scale network perspective; iii) to study the relationship between altered networks and; iv) to find out whether chronic pain targets clusters of areas. Our results showed that chronic pain causes both core and pathology-specific gray matter alterations in large-scale networks. Common alterations were observed in the prefrontal regions, in the anterior insula, cingulate cortex, basal ganglia, thalamus, periaqueductal gray, post- and pre-central gyri and inferior parietal lobule. We observed that the salience and attentional networks were targeted in a very similar way by different chronic pain pathologies. Conversely, alterations in the sensorimotor and attention circuits were differentially targeted by chronic pain pathologies. Moreover, model-based clustering revealed that chronic pain, in line with some neurodegenerative diseases, selectively targets some large-scale brain networks. Altogether these findings indicate that chronic pain can be better conceived and studied in a network perspective.
authors.affiliation: GCS fMRI, Koelliker Hospital, Department of Psychology, University of Turin, Turin, Italy ; Functional Neuroimaging and Complex Systems Group, Department of Psychology, University of Turin, Turin, Italy ; Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Cauda
authors.affiliation: Functional Neuroimaging and Complex Systems Group, Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Palermo
authors.affiliation: GCS fMRI, Koelliker Hospital, Department of Psychology, University of Turin, Turin, Italy ; Functional Neuroimaging and Complex Systems Group, Department of Psychology, University of Turin, Turin, Italy ; Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Costa
authors.affiliation: Department of Neuroscience, AOU San Giovanni Battista, Turin, Italy ; Psycho-Oncology and Clinical Psychology Unit, University of Turin, Città della Salute e della Scienza, Turin, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Torta
authors.affiliation: GCS fMRI, Koelliker Hospital, Department of Psychology, University of Turin, Turin, Italy ; Functional Neuroimaging and Complex Systems Group, Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Duca
authors.affiliation: GCS fMRI, Koelliker Hospital, Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Ugo
authors.initials: U
authors.lastname: Vercelli
authors.affiliation: GCS fMRI, Koelliker Hospital, Department of Psychology, University of Turin, Turin, Italy ; Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Geminiani
authors.affiliation: GCS fMRI, Koelliker Hospital, Department of Psychology, University of Turin, Turin, Italy ; Functional Neuroimaging and Complex Systems Group, Department of Psychology, University of Turin, Turin, Italy ; Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Diana M E
authors.initials: DM
authors.lastname: Torta
mesh_terms: D000328:Adult; D001931:Brain Mapping; D059350:Chronic Pain / Q000473:pathology*; D016000:Cluster Analysis; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016013:Likelihood Functions; D008279:Magnetic Resonance Imaging; D008297:Male; D055815:Young Adult
keywords: Brain networks; Chronic pain; Gray matter alterations; Voxel-Based Metaanalysis