title: White matter lesions in euthymic patients with bipolar disorder.
abstract: OBJECTIVE
  We aimed to quantify both load and regional distributions of hyperintensities on magnetic resonance imaging (MRI) in prospectively verified euthymic bipolar patients and matched controls.
  
  
  METHODS
  Cerebral hyperintensities on T2, proton density and fluid-attenuated inversion recovery (FLAIR) MRI were compared between 48 bipolar and 47 control subjects using semi-quantitative rating scales.
  
  
  RESULTS
  Bipolar subjects had more severe frontal deep white matter lesions (DWML). Hyperintensity load was independent of age in bipolar patients but increased with age in controls. Global prevalence and severity of hyperintensities did not differ between groups. Exploratory analysis showed DWML in excess in the left hemisphere in bipolar subjects but not in controls.
  
  
  CONCLUSIONS
  Findings are consistent with clinical, particularly some neurocognitive, features of bipolar disorder and implicate fronto-subcortical circuits in its neurobiology. They more probably reflect a trait abnormality or illness scar rather than a mood state-dependent finding. Processes other than ageing and vascular factors may underlie their development.
authors.affiliation: Psychobiology Group and Stanley Research Centre, Institute of Neuroscience, University of Newcastle upon Tyne NE1 4LP, Newcastle upon Tyne, UK. a.j.lloyd@ncl.ac.uk
authors.forename: A J
authors.initials: AJ
authors.lastname: Lloyd
authors.forename: P B
authors.initials: PB
authors.lastname: Moore
authors.forename: D A
authors.initials: DA
authors.lastname: Cousins
authors.forename: J M
authors.initials: JM
authors.lastname: Thompson
authors.forename: V L
authors.initials: VL
authors.lastname: McAllister
authors.forename: J H
authors.initials: JH
authors.lastname: Hughes
authors.forename: I N
authors.initials: IN
authors.lastname: Ferrier
authors.forename: A H
authors.initials: AH
authors.lastname: Young
mesh_terms: D000367:Age Factors; D001714:Bipolar Disorder / Q000473:pathology* / Q000503:physiopathology / Q000523:psychology; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology* / Q000502:physiology; D012720:Severity of Illness Index