External intercostal muscles and external anal sphincter electromyographic activity during coughing.

Few studies focused on concomitant electromyographic recordings of pelvic floor muscles and muscles involved in cough initiation. The objective of this study was to investigate the temporal course of external anal sphincter activation during coughing. Informed consent was obtained from ten healthy volunteers and ten women presenting with stress urinary incontinence (SUI). Simultaneously, recordings of electromyographic activity of external intercostal muscles (EIC EMGi) and external anal sphincter (EAS EMGi) during coughing have been performed. It was chosen to study intercostals muscles because they are synchronous to diaphragmatic muscle during cough initiation. Median (interquartile range) latency between the onset of the EAS EMGi and the onset of the EIC EMGi was -210 ms (-398; -135) and 0 ms (-30; +111.7) in volunteers' group and in SUI group, respectively (p = 0.0009). Abnormal temporal course of external anal sphincter activation is observed during coughing in women presenting with SUI compared to healthy volunteers.