Correlations between dynamic urethral profilometry and perivaginal pelvic muscle activity

Of 208 ambulatory female subjects evaluated for complaints of urinary incontinence, complete history, physical findings, and urodynamic data were available on 163 patients allowing correlation of measures of perivaginal muscle activity to urethral profilometry measurement of sphincter strength. Perivaginal measures include pelvic digital exam score as well as vaginal electromyography with a modified perinometer. Urethral profilometry was performed at rest and during pelvic muscle contractions in both supine and standing positions. There was a moderate and significant correlation (r = 0.19 to 0.32) between profilometry measures of voluntary sphincter contractions and perivaginal EMG parameters of endurance peak and area, as well as to the digital test parameters of pressure and displacement. The correlation values between the vaginal EMG and the Digital Test scale of perivaginal strength were higher (r = 0.28 to 0.74). When the patients with pure stress incontinence were stratified by degrees of incontinence (mild, moderate, severe), urethral prolfilometry measures were a more accurate indicator of severity of incontinence than measures of perivaginal strength or the degree of bladder neck mobility as measured by the Q-tip test.