Su2113 High-Intense Rectal Urgency and Its Representation in the Brain
2013 (English)In: Gastroenterology, ISSN 0016-5085, E-ISSN 1528-0012, Vol. 144, no 5, S561-S561 p.Article in journal, Meeting abstract (Refereed) Published
Background: Several brain imaging studies have demonstrated that visceral distensions activate the insular cortex but there is limited knowledge about which subregions of the insula underpin the feeling of rectal urgency. An isobaric rectal balloon distension can be subdivided into the inflation phase when pressure is rising (rise) and a stable phase, when the pressure is constant. The rise phase is characterized by a more distinct sensation of urgency (Akervall et al., 1988). We aimed to study the BOLD response during the rise phase of a standardized rectal distension in subregions of the insula, in healthy controls.
Method:Twenty right-handed female healthy volunteers (mean age 32.2 yrs, range 21-54) were included. Rectal pressure sensory thresholds were determined before functional Magnetic Resonance Imaging (fMRI) while the subjects were placed in the MR scanner. Blood Oxygen Level Dependent (BOLD) signals were measured during the rise periods (6.6-7.2 sec) of 20 rectal distensions (45mmHg). Regions of interest (ROIs) included 10 insula subregions: Left (L) and right (R) anterior ventral, anterior dorsal, posterior ventral, posterior dorsal and mid insula. Results were reported as significant if peak p-value were, 0.05 with familywise error (FWE) correction in the ROIs.
Results: The mean values for rectal sensory thresholds for first sensation, first sensation of urgency and maximum tolerable distension were 16 mmHg (SD 3.9), 28mmHg (SD 6.2) and 55 mmHg (SD 12.3), respectively. Complete fMRI data were available from 18 subjects. The rise period of the rectal distension generated significant BOLD activation in the right hemisphere in the anterior dorsal, anterior ventral, mid and posterior ventral parts of the insula. On the left side BOLD activity was generated in mid, posterior ventral and posterior dorsal parts of the insula but not in the anterior insula. Akervall S et al, 1988, Manovolumetry: A new method for investigation of anorectal function. Gut 29:614-623.
Place, publisher, year, edition, pages
2013. Vol. 144, no 5, S561-S561 p.
IdentifiersURN: urn:nbn:se:liu:diva-113419DOI: 10.1016/S0016-5085(13)62074-0OAI: oai:DiVA.org:liu-113419DiVA: diva2:781818
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