Standardization of anal sphincter electromyography: Effect of chronic constipation

Severe chronic constipation has been implicated as a cause of damage to the pelvic floor innervation. The aim of the present study was to examine the role of mild to moderate chronic constipation, a condition more relevant fo r clinical electromyographers, because this complaint is common in patients sent for evaluation of possible neurogenic dysfunction of lower sacral myo tomes, A group of 59 subjects without major uroneurological dysfunction, pr octological disorders, or neurological abnormalities participated in the st udy, which involved concentric needle electromyography of the external anal sphincter (EAS). Motor unit potentials (MUPs; sampled using multi-MUP anal ysis) and interference pattern (IP, sampled using turn/ amplitude analysis) of chronically constipated and control subjects were compared. No effect o f chronic constipation on MUP/IP parameters compatible with neurogenic inju ry was found. Our results suggest that mild chronic constipation does not c ause damage to the EAS innervation, and that no separate reference values a re needed for this group of subjects, (C) 2000 John Wiley & Sons, Inc.