title: Combined analysis of grey matter voxel-based morphometry and white matter tract-based spatial statistics in late-life bipolar disorder.
abstract: BACKGROUND
  Previous magnetic resonance imaging (MRI) studies in young patients with bipolar disorder indicated the presence of grey matter concentration changes as well as microstructural alterations in white matter in various neocortical areas and the corpus callosum. Whether these structural changes are also present in elderly patients with bipolar disorder with long-lasting clinical evolution remains unclear.
  
  
  METHODS
  We performed a prospective MRI study of consecutive elderly, euthymic patients with bipolar disorder and healthy, elderly controls. We conducted a voxel-based morphometry (VBM) analysis and a tract-based spatial statistics (TBSS) analysis to assess fractional anisotropy and longitudinal, radial and mean diffusivity derived by diffusion tensor imaging (DTI).
  
  
  RESULTS
  We included 19 patients with bipolar disorder and 47 controls in our study. Fractional anisotropy was the most sensitive DTI marker and decreased significantly in the ventral part of the corpus callosum in patients with bipolar disorder. Longitudinal, radial and mean diffusivity showed no significant between-group differences. Grey matter concentration was reduced in patients with bipolar disorder in the right anterior insula, head of the caudate nucleus, nucleus accumbens, ventral putamen and frontal orbital cortex. Conversely, there was no grey matter concentration or fractional anisotropy increase in any brain region in patients with bipolar disorder compared with controls.
  
  
  CONCLUSIONS
  The major limitation of our study is the small number of patients with bipolar disorder.
  
  
  CONCLUSIONS
  Our data document the concomitant presence of grey matter concentration decreases in the anterior limbic areas and the reduced fibre tract coherence in the corpus callosum of elderly patients with long-lasting bipolar disorder.
authors.affiliation: Service neuro-diagnostique et neuro-interventionnel DISIM, University Hospitals of Geneva, Geneva, Switzerland. sven.haller@hcuge.ch
authors.forename: Sven
authors.initials: S
authors.lastname: Haller
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Xekardaki
authors.forename: Christophe
authors.initials: C
authors.lastname: Delaloye
authors.forename: Alessandra
authors.initials: A
authors.lastname: Canuto
authors.forename: Karl Olof
authors.initials: KO
authors.lastname: Lövblad
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gold
authors.forename: Panteleimon
authors.initials: P
authors.lastname: Giannakopoulos
mesh_terms: D000368:Aged; D016880:Anisotropy; D001714:Bipolar Disorder / Q000473:pathology* / Q000523:psychology; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging / Q000379:methods / Q000523:psychology* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D036421:Nerve Fibers, Unmyelinated / Q000473:pathology*; D059906:Neuroimaging / Q000379:methods / Q000523:psychology* / Q000706:statistics & numerical data; D009483:Neuropsychological Tests / Q000706:statistics & numerical data