Endocrinologic Aspects of Disturbed Potency

Bulbocavernosus reflex: its validity as a diagnostic test of neurogenic impotence

Measurement of the bulbocavernosus reflex is used widely to diagnose underlying neurogenic disorders in erectile dysfunction. A prolonged bulbocavernosus reflex latency (that is more than 45 msec.) or the absence of a reflex response of the bulbocavernosus muscles during electrical stimulation of the glans penis is considered a sign of neurological disease. Since only a few experimental studies have been performed in man related to the neurophysiological mechanism of erection, and since the results of these studies were contradictory the diagnostic validity of bulbocavernosus reflex measurement was reassessed. We determine whether men with abnormal bulbocavernosus reflex latencies have concomitant organic erectile dysfunction as confirmed by nocturnal plethysmographic and rigidity recordings. The bulbocavernosus reflex was recorded in 90 subjects and 19 had abnormal bulbocavernosus reflex latencies. Of these 19 subjects 8 had normal nocturnal erections, thus, confirming a diagnosis of psychogenic impotence. These results cast some doubts on the validity of bulbocavernosus reflex measurement for the diagnosis of organic erectile dysfunction due to a neurological disease.

Practical diagnostic screening for impotence

The author presents the view that there is a real need to diagnose impotence in more detail as demand for physiologic solutions to erectile dysfunction make inroads into the simplistic solution offered by penile implantation. Penile blood pressure measurements are diagnostic of vascular insufficiency only when values are low, since it is possible to demonstrate obstructive disease of the internal pudendal artery and its branches with selective arteriography of the presence of normal penile blood pressure. A rational approach to the workup of impotence is called for and practitioners are asked to weigh the ultimate usefulness of each test in the context of the individual patient's needs.