TRANSCUTANEOUS ELECTRORECTOGRAPHY - HUMAN ELECTRORECTOGRAPHY FROM SURFACE ELECTRODES

The rectal electric activity or electrorectography was recorded transc utaneously in 24 healthy volunteers (mean age 39.6 years). A silver-si lver chloride electrode was applied lateral to each of the two sacroil iac joints, and a third one was placed midway between the left greater trochanter and the ischial tuberosity. The reference electrode was ap plied to the right lower limb. At least two 20-min recording sessions were performed for each of the 24 subjects. In addition, an intrarecta l electrorectographic recording was done in 10 of the 24 subjects usin g silver-silver chloride electrodes attached to the rectal mucosa by s uction. Pacesetter potentials (PPs) were recorded transcutaneously. Th e wave was triphasic with a small positive, a large negative and anoth er small positive deflection. PPs had a regular rhythm and were reprod ucible. The mean frequency was 3.1 cycles/min. The transcutaneously re corded PPs could be confirmed by the intrarectal route. Both routes ha d similar electrorectographic recordings, except for the action potent ials (APs) which did not show in the transcutaneous electrorectogram. In conclusion, the study demonstrates that PPs could be recorded trans cutaneously. Transcutaneous electrorectography is simple, easy, reprod ucible and cost-effective, and may prove to be a useful investigative tool in the diagnosis of anorectal disorders.