Visceral hypersensitivity in irritable bowel syndrome (IBS) patients has been documented by evaluation of perceived stimulations.
The hypersensitivity can reflect abnormalities of both sensory neurocircuitry and cognitive processes.
The presence of actual neurohypersensitivity in human beings has not been documented separately.
Subliminal stimulations are free from the influence of stimulus-related cognitive processes.
In addition, functional magnetic resonance imaging and cortical response to these stimuli can be considered a measure of activity of the neural circuitry alone.
Dr Adeyemi Lawal and colleagues evaluated the cerebral cortical functional magnetic resonance imaging activity response to equal subliminal stimulations.
The researchers compared the responses between irritable bowel syndrome patients and age- and sex-matched controls.
|Magnetic resonance imaging activity volume in IBS was larger with all 3 pressures|
|Amercian Journal of Gastroenterology|
The team studied 10 irritable bowel syndrome patients and 10 healthy controls using a computerized barostat-controlled rectal distention device.
Functional magnetic resonance imaging activity volume and percent maximum signal intensity change for equal subliminal distention pressures were compared.
The researchers used 3 levels of subliminal distention pressures and analyzed for functional magnetic resonance imaging response in both controls and patients.
In all 3 distention levels, the functional magnetic resonance imaging activity volume in irritable bowel syndrome patients was larger.
The team found that the percent maximum signal intensity change was similar between irritable bowel syndrome patients and controls.
Dr Lawa's team concluded, “The volume of cerebral cortical activity response to equal subliminal distention pressures in irritable bowel syndrome patients is significantly larger than in controls.”
“The study documents the existence of hypersensitivity of the neural circuitry in this patient group, irrespective of stimulus-related cognitive processes."