title: Differential relations between fronto-limbic metabolism and executive function in patients with remitted bipolar I and bipolar II disorder.
abstract: OBJECTIVE
  The aim of this study was to investigate the relationship between resting brain glucose metabolism and cognitive profiles in patients with remitted bipolar I disorder (BD-I) and bipolar II disorder (BD-II). We hypothesized that BD-I patients (compared to BD-II patients) would perform worse on tests of cognitive function because of abnormal metabolism in the prefrontal cortex and other mood-related brain areas.
  
  
  METHODS
  Thirty-four patients with remitted bipolar disorder (BD) (BD-I = 17, BD-II = 17) under treatment and 17 well-matched healthy controls received both fluorodeoxyglucose ((18) F-FDG) positron emission tomography (PET) and neuropsychological tests of attention, memory, and executive function.
  
  
  RESULTS
  Clinical features in patients with BD-I and BD-II were comparable. Executive function, as indicated by performance on the Wisconsin Card Sorting Test, was significantly worse (i.e., higher percentage of errors, lower percentage of conceptual level responses, and fewer categories completed) in BD-I patients than in BD-II patients and healthy subjects. No difference in attention and memory tests was found among these three groups. Brain PET analysis showed that BD-I patients (compared to BD-II patients) had significantly lower glucose uptake in the bilateral anterior cingulum, insula, striatum, and part of the prefrontal cortex, and higher glucose uptake in the left parahippocampus. Further analyses revealed significant correlations between poor executive function and abnormal glucose uptake in other brain areas in BD-I patients.
  
  
  CONCLUSIONS
  There are neurobiological differences between subtypes of BD. BD-I is associated with more impaired fronto-limbic circuitry, which might account for reduced executive function in BD-I patients during remission.
authors.affiliation: Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Cheng-Ta
authors.initials: CT
authors.lastname: Li
authors.forename: Jen-Chuen
authors.initials: JC
authors.lastname: Hsieh
authors.forename: Shyh-Jen
authors.initials: SJ
authors.lastname: Wang
authors.forename: Bang-Hung
authors.initials: BH
authors.lastname: Yang
authors.forename: Ya-Mei
authors.initials: YM
authors.lastname: Bai
authors.forename: Wei-Chen
authors.initials: WC
authors.lastname: Lin
authors.forename: Chen-Chia
authors.initials: CC
authors.lastname: Lan
authors.forename: Tung-Ping
authors.initials: TP
authors.lastname: Su
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000145:classification / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D056344:Executive Function / Q000502:physiology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008032:Limbic System / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18