title: Different cortical underpinnings for fatigue and depression in MS?
abstract: BACKGROUND
  Fatigue is a common complaint in MS patients but its origins are still not fully understood. A major difficulty is that fatigue seems strongly correlated with depression.
  
  
  METHODS
  95 MS patients and 15 healthy control subjects were included. The Fatigue Severity Scale and Beck's Depression Inventory were used to assess symptom-severity and to determine group membership for five groups: MS patients with and without fatigue, and with or without depressive mood, healthy controls. Participants were scanned using high-resolution structural 3D T1-weighted imaging. Cortical thickness for 84 areas was calculated using the NeuroQLab software in combination with the atlas for the Automated Anatomical Labeling software. A stepwise forward regression analysis was performed to predict group membership of the MS patients by thickness of cortical areas. We also performed a series of post-hoc ANOVAs to explore differences between the four patients groups and the healthy controls.
  
  
  RESULTS
  About 20% of the patients suffered only from fatigue or only from depressive mood. Regression analysis explained 17.3% of the variance and thickness of the right inferior parietal cortex, middle temporal pole and parahippocampus contributed significantly to the model. Patients with pure fatigue showed a specific decrease in cortical thickness in the inferior parietal lobe, patients with both depressive mood and fatigue in the right middle temporal pole. Additional ANOVAs revealed cortical thinning in the right middle cingulate cortex in the group with pure fatigue as well as the groups with depression.
  
  
  CONCLUSIONS
  Fatigue and depression can be dissociated in larger MS-patient groups using questionnaires and cortical thickness measures, but the cortical thickness measures only explain a small portion of variance of these neuropsychiatric symptoms.
authors.affiliation: University of Oldenburg, Department of Psychology, 26111 Oldenburg, Germany; Klinikum Bremen-Ost, Department of Neurology, Züricher Str. 40, 28325 Bremen, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Hanken
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Eling
authors.affiliation: Fraunhofer MEVIS Institute for Medical Image Computing, Universitätsallee 29, 28359 Bremen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Klein
authors.affiliation: Neurological Rehabilitation Unit Oldenburg, Brandenburger Straße 31, 26133 Oldenburg, Germany.
authors.forename: Esther
authors.initials: E
authors.lastname: Klaene
authors.affiliation: University of Oldenburg, Department of Psychology, 26111 Oldenburg, Germany; Klinikum Bremen-Ost, Department of Neurology, Züricher Str. 40, 28325 Bremen, Germany. Electronic address: helmut-hildebrandt@uni-oldenburg.de.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hildebrandt
mesh_terms: D000328:Adult; D001284:Atrophy; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000473:pathology; D003863:Depression / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D004185:Disability Evaluation; D005221:Fatigue / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology / Q000523:psychology*; D009929:Organ Size; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012720:Severity of Illness Index; D012984:Software
keywords: Brain atrophy; Cortical thickness measures; Depressive mood; Fatigue; Multiple sclerosis