[Neurobiology of ejaculation and orgasm disorders]. / Neurobiología de las alteraciones de la eyaculación y orgasmo.

OBJECTIVE: To determine the neurologic alterations of patients with ejaculatory and orgasmic disorders. METHODS: A study of the neuroandrologic profile was performed in eight patients; 6 presented an ejaculation, one premature ejaculation and one presented an orgasm. The neuroandrologic profile consisted in performing selective electromyography of the bulbocavernosus muscle, recording of the S2-S4 evoked potentials, evoked somatosensory potentials of the pudendal nerve, electromyography of the smooth cavernous muscle (SPACE), sympathetic skin response and cystometry. RESULTS: The sympathetic lesion was more frequent in the cases with an ejaculation (four cases; 66%); a pudendal efferent lesion was demonstrated in one case (17%) and a suprasacral lesion in one case (16%). A pudendal afferent lesion was observed in the two cases with premature ejaculation (100%). Both cases with an orgasm had a pudendal afferent lesion (100%) and one of them also presented a sympathetic lesion (50%). CONCLUSIONS: An ejaculation appears to be caused by sympathetic, motor pudendal or suprasacral lesion. An altered perception of genital sensations due to lesion of the afferent pudendal pathway appears to be present in premature ejaculation. An orgasm could be ascribed to an alteration of the pudendal sensibility or to the absence of ejaculation.