Brain imaging and functional gastrointestinal disorders: has it helped our understanding?

Correspondence to: Dr Q Aziz, University of Manchester, Section of GI Sciences, Hope Hospital, Salford, Lancashire M6 8HD, UK; [email protected] _________________________ T he 1990s were heralded as the ‘‘decade of the brain’’ amid excitement that major advances in imaging technology coupled with huge financial investment would finally allow neuroscientists to unravel the mysteries of the human brain. Several gastrointestinal disease research groups, frustrated by the lack of objective methods to assess gastrointestinal sensory dysfunction in functional gastrointestinal disorders (FGD), recognised this period as an opportunity to utilise these new brain imaging techniques and gain a novel insight into brain-gut interactions. What followed was a period of intense activity and a flurry of publications describing the cortical representation of visceral sensation appeared (for review see Derbyshire). It seemed only a matter of time before central mechanisms for chronic gastrointestinal pain in FGD patients would be identified, and appropriate treatment strategies designed. Nearly a decade on from the initiation of these studies, we are still waiting. The apparent failure of brain imaging to have an impact on the diagnosis and treatment of FGD has, rather like the emperors new clothes, led an increasing number of sceptics to wonder whether this has been another false dawn in the search for a solution to the problem of chronic pain in FGD. Despite such scepticism, we believe that brain imaging has greatly increased our understanding of the neuroanatomy and functional relevance of the cortical and subcortical structures involved in processing gastrointestinal sensation. The aim of this article is to guide the reader through a summary of this information, paying particular attention to its relevance to FGD.