A Roles of Cinedefecography and Electromyography in the Diagnosis of Paradoxical Puborectalis Syndrome

ABSTRACT

BACKGROUND: Paradoxical puborectalis syndrome (PPS) is a complex and poorly understood entity characterized by contraction rather than relaxation of the pelvic floor muscles during attempted evacuation. Anal electromyography (EMG) and cinedefecography (CD) are the most commonly used tests for the diagnosis of PPS. Therefore, the aim of this study was to prospectively assess the correlation of EMG and CD in the diagnosis of PPS. METHODS: All patients with symptoms of obstructed evacuation who underwent EMG and CD between September 1998 and February 1999, were evaluated. The clinical criteria for PPS included incomplete or difficult evacuation, straining, tenesmus, and the need for an enema or digitation. The EMG criteria included failure to achieve a significant decrease in the electrical activity of the puborectalis during attempted evacuation. The CD criteria included either paradoxical contraction or failure of the puborectalis to relax along with incomplete evacuation. RESULTS: Twenty-nine (29) patients had clinical evidence of PPS, 8 males and 21 females with a mean age of 42.6 years (range, 19-75 years), and underwent CD and EMG. The mean duration of symptoms was 7.2 years (range, 3 months-30 years). Nineteen patients (65.5%) had evidence as having PPS on CD and/or EMG. Of these patients, six patients (20.7%) were diagnosed as having PPS on both tests, five patients (17.2%) were only diagnosed on CD, and eight patients (27.6%) were only diagnosed on EMG. The remaining ten patients had normal puborectalis muscle relaxation on CD and EMG. Therefore, the correlation rate between the two tests was 55.2%. If EMG was considered as the ideal test for the diagnosis of PPS, CD had a sensitivity of 42.9% and a specificity of 66.7%. Conversely, if CD was considered as the ideal test, EMG had a sensitivity of 54.5% and a specificity of 55.6%. CONCLUSIONS: The sensitivity and the specificity values of EMG and CD for the diagnosis of PPS are suboptimal, and a low correlation existed between the two tests. This result suggests that the diagnosis of PPS should not be based upon only one test.