ROLE OF PUDENDAL NERVE-TERMINAL MOTOR LATENCY ASSESSMENT IN CONSTIPATED PATIENTS

The importance of pudendal nerve terminal motor latency assessment for the evaluation of incontinence is well established. However, its role in constipated patients remains unclear. PURPOSE: The purpose of the present study was to assess the incidence of pudendal neuropathy in co nstipated patients and its correlation with others variables including age, sex, anal pressures, and anal electromyography. RESULTS: From 19 88 to 1993, 161 patients with chronic constipation underwent pudendal nerve terminal motor latency assessment, anal electromyography, and an al manometry. The overall incidence of pudendal neuropathy was 23.6 pe rcent; females and males had a similar incidence (24 percent us. 23 pe rcent, respectively; P > 0.05). Patients over 70 years old had a signi ficantly higher incidence of pudendal neuropathy than did patients und er 70 years (37 percent vs. 12 percent, respectively; P < 0.01). Patie nts with paradoxical puborectalis contraction on anal electromyographi c assessment had a higher incidence of bilateral neuropathy; paradoxic al puborectalis contraction (+)23 percent vs. paradoxical puborectalis contraction (-)8 percent, P < 0.05. Patients with pudendal neuropathy also had a higher incidence of decreased motor units potential recrui tment than did patients without pudendal neuropathy (31.5 percent vs. 17 percent, respectively; P > 0.05). CONCLUSIONS: Pudendal nerve termi nal motor latency assessment was able to detect unsuspected pudendal n europathy in 24 percent of patients. This finding correlated with age and with the presence of paradoxical puborectalis contraction but not with manometric anal pressures, motor unit potentials recruitment, or the presence of polyphasia. However, the often espoused relationship b etween pudendal latency and external sphincter function could not be d emonstrated.