Evoked sacral potentials in subjects with true premature ejaculation.

Evoked sacral potentials were used to study the bulbo-cavernous reflex in 85 patients with true premature ejaculation (TPE) and in 52 subjects as a control group. In the perineal and perianal recordings the amplitudes of the evoked responses (means +/- SD) were 70 +/- 91.1 microV and 35.6 +/- 36 microV in the TPE patients, and 39.2 +/- 36.8 microV and 26 +/- 21.6 microV in the controls, respectively. Both these differences resulted significant (P less than 0.01 and P congruent to 0.05, respectively). Our results suggest a reflex hyperexcitability, or an impaired "modulation" of the motor neurons of the pudendal nucleus by the regulating upper centers in the TPE patients.