Miwako Kagawa, Tetsuji Takayama, Hiromi Yano, Rie Harada, Miyako Niki, Azusa Saito, Tetsu Tomonari, Tetsuo Kimura, Koichi Okamoto, Seisuke Okamura, Masako Kaji, Shinji Kitamura, Toshiya Okahisa, and Miho Tsuda
Purpose: Mobility disorders of the alimentary tract including irritable bowel syndrome (IBS) is now increasing worldwide. Measurement of intracolonic pressure has been conventionally employed for assessment of colonic motility. However, it is very laborious and burdensome for a routine examination. Therefore, in this study, we performed electrocolonography (ECoG), an easy and simple methodology, and investigated its usefulness for evaluation of colonic motility in comparison with the conventional methodology. Method: Twenty-five well-informed healthy volunteers were enrolled. ECoG was performed using a portable electrogastrograph (NIPRO EGG, A&D, Tokyo, Japan). After detecting a sigmoid colon using external ultrasonography, 4 electrodes of ECoG were attached to the abdomen. The ECoG was recorded by a bipolar lead between the central electrode and 3 surface probe electrodes (Ch1-3) at 1-second interval with frequencies of 1.5-6.0 cpm. Mosapride (10mg) or butylscopolamine (10mg) was orally administered during the examinations. For the analysis of ECoG data, the dominant frequencies and peak powers in 3 channels were calculated using a Fast Fourier Transform. In the 3 subjects, intracolonic pressure was measured using mobility visualization system (ManoScan 360, Sierra Scientific Instruments, CA) concurrently with ECoG. A catheter with 36 pressure sensors was introduced through the anus to the sigmoid colon, and the change of the pressure at each point was recorded. Results: Colonic peristalsis at about 2 cpm (1.95 0.41 cpm) was observed by mobility measuring system. The pressure was significantly increased by administration of mosapride, and was decreased by butylscopolamine, consistent with the previous reports. While, a dominant frequency at 2 cpm, which represented action potential of colonic peristalsis, was observed in all channels of ECoG. The peak power of the dominant frequency was significantly increased by mosapride (pre 15.0 ± 7.38uV, after 52.0 ± 50.3uV) and was significantly decreased by butylscopolamine (pre 15.2 ± 6.27uV, after 0.35 ± 0.24uV), corresponding to the change of intracolonic pressure. The dominant frequency did not change after administration of mosapride or butylscopolamine in ECoG. Conclusion:We could detect action potential of colonic peristalsis by ECoG, an easy and simple methodology, and showed the usefulness of ECoG for assessing colonic motility.