Anal sphincter EMG in anorectal disorders

In 26 patients with different anorectal disorders electromyography was performed in combination with anal manometry. EMG was carried out with a concentric needle electrode as well as with a single fibre electrode. Also the pudendal nerve terminal motor latency (PNTML) was assessed. A relationship was found between maximal squeeze pressure in anal manometry and maximal voluntary contraction pattern in concentric needle EMG. Mean fibre density (FD) was increased while mean PNTML was not increased. However a relationship was found between PNTML and FD. This discrepancy, increased FD with normal PNTML could mean that a myogenic factor plays an important role in our patients.