title: Cognitive performance in irritable bowel syndrome: evidence of a stress-related impairment in visuospatial memory.
abstract: BACKGROUND
  Central nervous system (CNS) dysfunction is a prominent feature of the functional gastrointestinal (GI) disorder, irritable bowel syndrome (IBS). However, the neurobiological and cognitive consequences of key pathophysiological features of IBS, such as stress-induced changes in hypothalamic-pituitary-adrenal (HPA)-axis functioning, is unknown. Our aim was to determine whether IBS is associated with cognitive impairment, independently of psychiatric co-morbidity, and whether cognitive performance is related to HPA-axis function.
  
  
  METHODS
  A cross-sectional sample of 39 patients with IBS, a disease control group of 18 patients with Crohn's disease (CD) in clinical remission and 40 healthy age- and IQ-matched control participants were assessed using the Paired Associates Learning (PAL), Intra-Extra Dimensional Set Shift (IED) and Spatial Working Memory (SWM) tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and a computerized Stroop test. HPA-axis function was determined by measuring the cortisol awakening response (CAR).
  
  
  RESULTS
  IBS patients exhibited a subtle visuospatial memory deficit at the PAL six- pattern stage (p = 0.03), which remained after psychiatric co-morbidity was controlled for (p = 0.04). Morning cortisol levels were lower in IBS (p = 0.04) and significantly associated with visuospatial memory performance within IBS only (p = 0.02).
  
  
  CONCLUSIONS
  For the first time, altered cognitive function on a hippocampal-mediated test of visuospatial memory, which was related to cortisol levels and independent of psychiatric co-morbidity, has been identified in IBS. Visuospatial memory impairment may be a common, but currently neglected, component of IBS. Further elucidation of the nature of this impairment may lead to a greater understanding of the underlying pathophysiology of IBS, and may provide novel therapeutic approaches.
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: P J
authors.initials: PJ
authors.lastname: Kennedy
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: G
authors.initials: G
authors.lastname: Clarke
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: A
authors.initials: A
authors.lastname: O'Neill
authors.affiliation: Department of Psychology, University of Hull, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Groeger
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: E M M
authors.initials: EM
authors.lastname: Quigley
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: F
authors.initials: F
authors.lastname: Shanahan
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: J F
authors.initials: JF
authors.lastname: Cryan
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: T G
authors.initials: TG
authors.lastname: Dinan
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000209:etiology; D003424:Crohn Disease / Q000150:complications / Q000523:psychology; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000523:psychology*; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D065852:Spatial Memory / Q000502:physiology*; D013315:Stress, Psychological / Q000150:complications*