Rectal Somatosensory Evoked Potential in Normal Subjects

J Korean Assoc EMG Electrodiagn Med 2000;2(1):35-38.
Published online May 9, 2000.

Abstract

Objectives : To investigate the afferent pathways for signaling of visceral sensation in response to anorectal electrical stimulation. Methods : The study population consisted of healthy 28 males and 22 females. The stimulus was applied via anal probe equipped with bipolar surface stimulating electrode, and the probe was postioned 10 cm above anus. Cerebral evoked response were recorded from 1 cm posterior to vertex (Cz´, international 10~20 system) by needle electrode. Results : We found recognizable and reproducible evoked potentias in 23 subjects. The 13 male and 10 female subjects had an series of successive peaks and troughs. The first component of response had negative peak potentials, 97.2±4.2 msec mean peak latency for men and mean peak latency of 89.2±3.1 msec for women. Conclusion : We demonstrated the feasibility of methods to study visceral afferent nervous system from anorectum. There is some evidence that cortical evoked potentials may be obtained after electrical stimulation of anal canal.

Key Words: Visceral sensation, Anorectal electrical stimulation, Cortical evoked potentials