Pudendal neuropathy and the importance of EMG evaluation of fecal incontinence.
A prospective study was undertaken to evaluate pudendal neuropathy in fecal incontinence. Fifty-two patients (38 women and 14 men) with fecal incontinence underwent manometric and electromyographic evaluation (measurement of pudendal nerve terminal motor latency [PNTML] and sphincter muscle mapping). The average age of all patients was 54 +/- 17 years. Fifty-two percent (27/52) were found to have a pudendal neuropathy (PNTML > 2.1 milliseconds). Seventeen of these 27 patients (63 percent) had a bilateral pudendal neuropathy. Patients with a pudendal neuropathy were older than those without a neuropathy (63.7 years vs. 51.9 years; P = 0.01). Women were significantly more likely than men to have a pudendal neuropathy (P = 0.03). Nine patients had an anatomic sphincter defect identified, and six of these (67 percent) had a neuropathy; 4/6 (67 percent) had a bilateral pudendal neuropathy. In the 43 patients who did not have an anatomic sphincter defect, there was no difference in resting pressure (69 mmHg vs. 60 mmHg; P = 0.4) or maximum voluntary contraction (95 mmHg vs. 86 mmHg; P = 0.5) when patients without a neuropathy were compared with those with a neuropathy. Patients with a pudendal neuropathy had a shorter sphincter length than those without a neuropathy (3.0 cm vs. 3.9 cm; P = 0.01). Bilateral pudendal neuropathy tended to occur more frequently in women (P = 0.08) and was not associated with poorer resting pressure, maximum voluntary contraction, or shorter sphincter length. We conclude that pudendal neuropathy is a common cause of fecal incontinence, particularly in older women, and frequently occurs in association with a sphincter defect. Manometric evaluation alone is not helpful in identifying the neuropathic patient. PNTMLs should be routinely measured in the evaluation of fecal incontinence.
Department of Surgery, St. Louis University School of Medicine, Missouri 63110.
A M
AM
Vernava
W E
WE
Longo
G L
GL
Daniel
D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000503:physiopathology; D004576:Electromyography; D005242:Fecal Incontinence / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009119:Muscle Contraction; D009132:Muscles / Q000294:innervation*; D010388:Pelvis / Q000294:innervation*; D010523:Peripheral Nervous System Diseases / Q000150:complications* / Q000503:physiopathology; D011312:Pressure; D011446:Prospective Studies; D012007:Rectum / Q000503:physiopathology; D012737:Sex Factors