CINEDEFECOGRAPHY AND ELECTROMYOGRAPHY IN THE DIAGNOSIS OF NONRELAXINGPUBORECTALIS SYNDROME

A prospective study was undertaken to assess the correlation between e lectromyography (EMG) and cinedefecography (CD) for the diagnosis of n onrelaxing puborectalis syndrome (NRPR). Clinical criteria for NRPR in cluded straining, incomplete evacuation, tenesmus, and the need for en emas, suppositories, or digitation. EMG criteria included failure to a chieve a significant decrease in electrical activity of the puborectal is (PR) during attempted evacuation. CD criteria included either parad oxical contraction or failure of relaxation of the PR along with incom plete evacuation. In addition, other etiologies for incomplete evacuat ion, such as rectoanal intussusception or nonemptying rectocele, were excluded by proctoscopy and defecography in all cases. One hundred twe lve patients with constipation, 81 females and 31 males, with a mean a ge of 59 (range, 12-83) years were studied by routine office evaluatio n, CD, and EMG. Forty-two patients (37 percent) had evidence of NRPR o n CD (rectal emptying: none, 24; incomplete, 18). Twenty-eight of thes e patients (67 percent) also had evidence of NRPR on EMG. EMG findings of NRPR were present in 12 of 70 patients (17 percent) with normal re ctal emptying. Conversely, 14 of 72 patients (19 percent) with normal PR relaxation on EMG had an NRPR pattern on CD. The sensitivity and sp ecificity for the EMG diagnosis of NRPR were 67 percent and 83 percent , and the positive and negative predictive values were 70 percent and 80 percent, respectively. Conversely, if EMG is considered as the idea l test for the diagnosis of NRPR, CD had a sensitivity of 70 percent, a specificity of 80 percent, and positive and negative predictive valu es of 66 percent and 82 percent, respectively. In summary, sensitivity , specificity, and predictive values of EMG and CD are suboptimal. The refore, a combination of these two tests is suggested for the diagnosi s of NRPR.