title: Functional neuroimaging studies in functional dyspepsia patients: a systematic review.
abstract: There is increasing evidence in support of the presence of abnormal central changes (compared to healthy controls) in functional dyspepsia (FD) in addition to the peripheral changes in gastrointestinal tract.
  
  
  
  This systematic review aims to provide an integrative understanding of the abnormal functional brain activity, visceral sensation, dyspeptic symptoms, and psychological changes of FD. Electronic and hand searches were conducted to identify functional neuroimaging studies involving FD patients. Sixteen studies were selected and divided into three categories: 10 resting state studies, three visceral distention studies, and three acupuncture studies. Changes were reported in several brain areas in FD patients including the frontal cortex, somatosensory cortex, insula, anterior cingulate cortex, thalamus, hippocampus, and amygdala. These brain activity changes were associated with visceral hypersensitivity, dyspeptic symptoms, poorer quality of life, anxiety, and depression. The results show that FD is associated with functional abnormalities in sensory and pain modulation, emotion, saliency, and homeostatic processing regions. The diversity of conditions, heterogeneous results, poorly standardized diagnoses of FD, and various comorbidities may be responsible for the variability in the results.
authors.affiliation: Psychosomatic Medicine and Psychotherapy Department, University of Tübingen, Tübingen, Germany.|Graduate Training Centre of Neuroscience, IMPRS for Cognitive and Systems Neuroscience, Tübingen, Germany.
authors.forename: I-S
authors.initials: IS
authors.lastname: Lee
authors.affiliation: Psychosomatic Medicine and Psychotherapy Department, University of Tübingen, Tübingen, Germany.|Graduate Training Centre of Neuroscience, IMPRS for Cognitive and Systems Neuroscience, Tübingen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.affiliation: Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Chae
authors.affiliation: Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany.|German Center for Diabetes Research, Tübingen, Germany.|Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany.|Department Pharmacy and Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Preissl
authors.affiliation: Psychosomatic Medicine and Psychotherapy Department, University of Tübingen, Tübingen, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Enck
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004415:Dyspepsia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods
keywords: PET; brain imaging; fMRI; functional dyspepsia; systematic review