title: Episodic memory impairments in bipolar disorder are associated with functional and structural brain changes.
abstract: OBJECTIVE
  We combined multimodal functional magnetic resonance imaging (fMRI) and structural magnetic resonance imaging to probe abnormalities in brain circuits underpinning episodic memory performance deficits in patients with bipolar disorder (BD).
  
  
  METHODS
  We acquired whole-brain fMRI data in 21 patients with BD and a matched group of 20 healthy controls during a non-verbal episodic memory task, using abstract shapes. We also examined density of gray matter, using voxel-based morphometry (VBM), and integrity of connecting fiber tracts, using diffusion tensor imaging (DTI) and tract-based spatial statistics, for areas with significant activation differences.
  
  
  RESULTS
  Patients with BD remembered less well than controls which shapes they had seen and had lower activation levels during the encoding stage of the task in the anterior cingulate gyrus, the precuneus/cuneus bilaterally, and the left lingual gyrus, and higher activation levels during the retrieval stage in the left temporo-parietal junction. Patients with BD showed reduced gray matter volumes in the left anterior cingulate, the precuneus/cuneus bilaterally, and the left temporo-parietal region in comparison with controls. DTI revealed increased radial, axial, and mean diffusivity in the left superior longitudinal fascicle in patients with BD compared with controls.
  
  
  CONCLUSIONS
  Changes in task-related activation in frontal and parietal areas were associated with poorer episodic memory in patients with BD. Compared with data from single imaging modalities, integration of multimodal neuroimaging data enables the building of more complete neuropsychological models of mental disorders.
authors.affiliation: Laboratory of Neurophysiology and Neuroimaging, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe University.
authors.forename: Viola
authors.initials: V
authors.lastname: Oertel-Knöchel
authors.forename: Britta
authors.initials: B
authors.lastname: Reinke
authors.forename: Richard
authors.initials: R
authors.lastname: Feddern
authors.forename: Annika
authors.initials: A
authors.lastname: Knake
authors.forename: Christian
authors.initials: C
authors.lastname: Knöchel
authors.forename: David
authors.initials: D
authors.lastname: Prvulovic
authors.forename: Johannes
authors.initials: J
authors.lastname: Pantel
authors.forename: David E J
authors.initials: DE
authors.lastname: Linden
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000150:complications*; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology* / Q000473:pathology*; D061212:Memory, Episodic; D008875:Middle Aged; D009434:Neural Pathways / Q000098:blood supply / Q000473:pathology; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011569:Psychiatric Status Rating Scales; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: DTI; VBM; bipolar disorder; fMRI; non-verbal episodic memory