title: Structural 'connectomic' alterations in the limbic system of multiple sclerosis patients with major depression.
abstract: BACKGROUND
  Major depression (MD) is a common psychiatric disorder in multiple sclerosis (MS). Despite the negative impact of MD on the quality of life of MS patients, little is known about its underlying brain mechanisms.
  
  
  OBJECTIVE
  We studied the whole-brain connectivity patterns that were associated with MD in MS. Alterations were mainly expected within limbic circuits.
  
  
  METHODS
  Diffusion tensor imaging data were collected in 20 MS patients with MD, 22 non-depressed MS patients and 16 healthy controls. We used deterministic tractography and graph analysis to study the white-matter connectivity patterns that characterized MS patients with MD.
  
  
  RESULTS
  We found that MD in MS was associated with increased local path length in the right hippocampus and right amygdala. Further analyses revealed that these effects were driven by an increased shortest distance between both the right hippocampus and right amygdala and a series of regions including the dorsolateral and ventrolateral prefrontal cortex, orbitofrontal cortex, sensory-motor cortices and supplementary motor area.
  
  
  CONCLUSIONS
  Our data provide strong support for neurobiological accounts positing that MD in MS is mediated by abnormal 'communications' within limbic circuits. We also found evidence that MD in MS may be linked with connectivity alterations at the limbic-motor interface, a group of regions that translates emotions into survival-oriented behaviors.
authors.affiliation: Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Nigro
authors.affiliation: Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy luca.passamonti@cnr.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Passamonti
authors.affiliation: Department of Medical and Surgical Sciences, 'Magna Graecia' University, Catanzaro, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Riccelli
authors.affiliation: Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy/AA Martinos Center for Biomedical Imaging, Harvard Medical School, Boston, MA, USA.
authors.forename: Nicola
authors.initials: N
authors.lastname: Toschi
authors.affiliation: Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Rocca
authors.affiliation: Department of Medical and Surgical Sciences, 'Magna Graecia' University, Catanzaro, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Valentino
authors.affiliation: Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Nisticò
authors.affiliation: Department of Medical and Surgical Sciences, 'Magna Graecia' University, Catanzaro, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Fera
authors.affiliation: Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy/Department of Medical and Surgical Sciences, 'Magna Graecia' University, Catanzaro, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Quattrone
mesh_terms: D000328:Adult; D000679:Amygdala / Q000473:pathology; D063132:Connectome; D003865:Major Depressive Disorder / Q000209:etiology / Q000473:pathology* / Q000523:psychology*; D056324:Diffusion Tensor Imaging; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008032:Limbic System / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000473:pathology* / Q000523:psychology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications / Q000473:pathology / Q000523:psychology; D009434:Neural Pathways / Q000473:pathology*; D066127:White Matter / Q000473:pathology; D055815:Young Adult
keywords: Diffusion Tensor Imaging (DTI); connectome; graph analysis; limbic circuits; major depression; multiple sclerosis; white-matter connectivity patterns