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External anal sphincter contraction during cough: Not a simple spinal reflex
Author(s) -
Deffieux Xavier,
Raibaut Patrick,
ReneCorail Patrick,
Katz Rose,
Perrigot Michel,
Ismael Samer Sheikh,
Thoumie Philippe,
Amarenco Gérard
Publication year - 2006
Publication title -
neurourology and urodynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 90
eISSN - 1520-6777
pISSN - 0733-2467
DOI - 10.1002/nau.20228
Subject(s) - medicine , external anal sphincter , reflex , diaphragmatic breathing , electromyography , anesthesia , contraction (grammar) , cough reflex , muscle contraction , pelvic floor , physical medicine and rehabilitation , surgery , anatomy , anal canal , rectum , alternative medicine , pathology
Aims: To assess whether the anal contraction during voluntary coughing is a simple spinal reflex‐mediated activity or not. To address this question we studied the external intercostal (EIC) muscle activity and external anal sphincter (EAS) response to cough. Materials and Methods: Electromyographic recordings were made from pre‐gelled disposable surface electrodes. EAS electromyographic recordings were made from the EAS of the pelvic floor in 15 continent women all suffering from urgency and/or frequency without urge or stress urinary incontinence, and referred for urodynamic investigation. Electromyographic signal was immediately integrated (EMGi). The abdominal pressure was recorded with bladder and rectal pressure. EAS EMGi was recorded during successive voluntary cough. In three women, we have also recorded EIC EMGi activity since it is synchronous with diaphragmatic EMG activity during cough initiation. Results: In all subjects, EAS EMGi activity precedes the onset of the abdominal pressure increase. The mean latency of EAS EMGi was 615 msec (±278). In the three subjects whose EMGi activity was recorded both on EAS and EIC, the onset of EAS EMGi activity occurred before the EIC EMGi activity (latency ranging from 40 to 780 msec) and before the increase in the abdominal pressure. Conclusions: The present study suggests that during coughing, EAS EMG activity increases before external intercostal muscle EMGi activity. The contraction of the EAS preceding the activation of muscles involved in coughing indicates that this response is not a result of a simple spinal reflex, but more likely the result of a more intricate reflex involving complex integrative centers. Neurourol. Urodynam. 25:782–787, 2006. © 2006 Wiley‐Liss, Inc.