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Cortical evoked potentials in response to rapid balloon distension of the rectum and anal canal
Author(s) -
Haas S.,
Brock C.,
Krogh K.,
Gram M.,
Nissen T. D.,
Lundby L.,
Laurberg S.,
Drewes A. M.
Publication year - 2014
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1111/nmo.12341
Subject(s) - rectum , anal canal , distension , reproducibility , medicine , anorectal manometry , coefficient of variation , latency (audio) , anatomy , repeated measures design , balloon , defecation , surgery , mathematics , statistics , electrical engineering , engineering
Background Neurophysiological evaluation of anorectal sensory function is hampered by a paucity of methods. Rapid balloon distension ( RBD ) has been introduced to describe the cerebral response to rectal distension, but it has not successfully been applied to the anal canal. Methods Nineteen healthy women received 30 RBD s in the rectum and the anal canal at intensities corresponding to sensory and unpleasantness thresholds, and response was recorded as cortical evoked potentials ( CEP s) in 64‐channels. The anal canal stimulations at unpleasantness level were repeated after 4 min to test the within‐day reproducibility. CEP s were averaged, and to overcome latency variation related to jitter the spectral content of single sweeps was also computed. Key Results Repeated stimulation of the anal canal generated CEP s with similar latencies but smaller amplitudes compared to those from the rectum. Due to latency jitter, reproducibility of averaged CEP s was lower than what was found in the rectum. The most reproducible feature was N2P2 peak‐to‐peak amplitude with intra‐class correlation coefficient ( ICC ) of 0.7 and coefficient of variation ( CV ) of 18%. Spectral content of the single sweeps showed reproducibility with ICC s for all bands >0.8 and corresponding CV s <7%. Conclusions & Inferences Cortical potentials evoked from the anal canal are challenged by latency jitter likely related to variability in muscle tone due to the distensions. Using single‐sweep analysis, anal CEP s proved to be reproducible and should be used in future evaluation of the anal function.