title: Cortical thickness and surface area relate to specific symptoms in early relapsing-remitting multiple sclerosis.
abstract: BACKGROUND
  Cortical atrophy is common in early relapsing-remitting multiple sclerosis (RRMS). Whether this atrophy is caused by changes in cortical thickness or cortical surface area is not known, nor is their separate contributions to clinical symptoms.
  
  
  OBJECTIVE
  To investigate the difference in cortical surface area, thickness and volume between early RRMS patients and healthy controls; and the relationship between these measures and neurological disability, cognitive decline, fatigue and depression.
  
  
  METHODS
  RRMS patients (n = 61) underwent magnetic resonance imaging (MRI), neurological and neuropsychological examinations. We estimated cortical surface area, thickness and volume and compared them with matched healthy controls (n = 61). We estimated the correlations between clinical symptoms and cortical measures within the patient group.
  
  
  RESULTS
  We found no differences in cortical surface area, but widespread differences in cortical thickness and volume between the groups. Neurological disability was related to regionally smaller cortical thickness and volume. Better verbal memory was related to regionally larger surface area; and better visuo-spatial memory, to regionally larger cortical volume. Higher depression scores and fatigue were associated with regionally smaller cortical surface area and volume.
  
  
  CONCLUSIONS
  We found that cortical thickness, but not cortical surface area, is affected in early RRMS. We identified specific structural correlates to the main clinical symptoms in early RRMS.
authors.affiliation: Oslo University Hospital, Norway/University of Oslo, Norway g.o.nygaard@medisin.uio.no.
authors.forename: Gro O
authors.initials: GO
authors.lastname: Nygaard
authors.affiliation: Oslo University Hospital, Norway/University of Oslo, Norway.
authors.forename: Kristine B
authors.initials: KB
authors.lastname: Walhovd
authors.affiliation: Oslo University Hospital, Norway/University of Oslo, Norway.
authors.forename: Piotr
authors.initials: P
authors.lastname: Sowa
authors.affiliation: University of Oslo, Norway.
authors.forename: Joy-Loi
authors.initials: JL
authors.lastname: Chepkoech
authors.affiliation: Oslo University Hospital, Norway/University of Oslo, Norway.
authors.forename: Atle
authors.initials: A
authors.lastname: Bjørnerud
authors.affiliation: Oslo University Hospital, Norway.
authors.forename: Paulina
authors.initials: P
authors.lastname: Due-Tønnessen
authors.affiliation: University of Oslo, Norway.
authors.forename: Nils I
authors.initials: NI
authors.lastname: Landrø
authors.affiliation: Karolinska Institutet, Stockholm, Sweden.
authors.forename: Soheil
authors.initials: S
authors.lastname: Damangir
authors.affiliation: Karolinska Institutet, Stockholm, Sweden.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Spulber
authors.affiliation: University of Oslo, Norway.
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Storsve
authors.affiliation: Oslo University Hospital, Norway/University of Oslo, Norway.
authors.forename: Mona K
authors.initials: MK
authors.lastname: Beyer
authors.affiliation: Oslo University Hospital, Norway/University of Oslo, Norway.
authors.forename: Anders M
authors.initials: AM
authors.lastname: Fjell
authors.affiliation: Oslo University Hospital, Norway.
authors.forename: Elisabeth G
authors.initials: EG
authors.lastname: Celius
authors.affiliation: Oslo University Hospital, Norway/University of Oslo, Norway.
authors.forename: Hanne F
authors.initials: HF
authors.lastname: Harbo
mesh_terms: D000328:Adult; D001284:Atrophy / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology*; D003072:Cognition Disorders / Q000209:etiology; D003863:Depression / Q000209:etiology; D005221:Fatigue / Q000209:etiology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications* / Q000473:pathology*; D009483:Neuropsychological Tests; D055815:Young Adult
keywords: Brain function; cerebral cortex; cortical surface area; cortical thickness; depression; fatigue; magnetic resonance imaging; multiple sclerosis; neurological disability; relapsing–remitting multiple sclerosis; symptoms