title: Sex-related differences in IBS patients: central processing of visceral stimuli.
abstract: OBJECTIVE
  Women have a higher prevalence of irritable bowel syndrome (IBS) and possible differences in response to treatment, suggesting sex-related differences in underlying pathophysiology. The aim of this study was to determine possible sex-related differences in brain responses to a visceral and a psychological stressor in IBS.
  
  
  METHODS
  Regional cerebral blood flow measurements using H(2)(15)O positron emission tomography were compared across 23 female and 19 male nonconstipated patients with IBS during a visceral stimulus (moderate rectal inflation) and a psychological stimulus (anticipation of a visceral stimulus).
  
  
  RESULTS
  In response to the visceral stimulus, women showed greater activation in the ventromedial prefrontal cortex, right anterior cingulate cortex, and left amygdala, whereas men showed greater activation of the right dorsolateral prefrontal cortex, insula, and dorsal pons/periaqueductal gray. Similar differences were observed during the anticipation condition. Men also reported higher arousal and lower fatigue.
  
  
  CONCLUSIONS
  Male and female patients with IBS differ in activation of brain networks concerned with cognitive, autonomic, and antinociceptive responses to delivered and anticipated aversive visceral stimuli.
authors.affiliation: Center for Neurovisceral Sciences and Women's Health, UCLA School of Medicine, CURE Building, 115/Room 223, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA. naliboff@ucla.edu
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Naliboff
authors.forename: Steve
authors.initials: S
authors.lastname: Berman
authors.forename: Lin
authors.initials: L
authors.lastname: Chang
authors.forename: Stuart W G
authors.initials: SW
authors.lastname: Derbyshire
authors.forename: Brandall
authors.initials: B
authors.lastname: Suyenobu
authors.forename: Brent A
authors.initials: BA
authors.lastname: Vogt
authors.forename: Mark
authors.initials: M
authors.lastname: Mandelkern
authors.forename: Emeran A
authors.initials: EA
authors.lastname: Mayer
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D002560:Cerebrovascular Circulation; D003109:Colonic Diseases, Functional / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology*; D012727:Sex Characteristics; D014055:Tomography, Emission-Computed; D014781:Viscera / Q000502:physiology*