[Several techniques proposed for the differential diagnosis of diabetic impotence]

The measurements of changes in penile circumference during nocturnal erection is commonly used to differentiate between organic and psychogenic impotence. Unfortunately, this measuring technique do not record variations in penile rigidity which may be insufficient to achieve coitus despite a normal circumference. We carried out a study with a penile cuff to measure penile rigidity. The validation of this penile cuff as a measurement device of penile rigidity permits us to determine the criteria of normality of penile rigidity and, subsequently, to differentiate more accurately between organic and psychogenic dysfunctions. Measurement of the bulbocavernous reflex (BCR) is widely used to diagnose underlying neurologic disorders in erectile dysfunctions. A prolonged BCR latency, more than 45 ms, or absence of a reflex response of the BC muscles during electrical stimulation of the glans penis, is considered like a sign of neurologic disease. We recorded the BCR in 90 subjects. Nineteen had abnormal BCR latencies. Furthermore, eight of these 19 subjects had normal nocturnal erections, thus confirming the diagnosis of psychogenic impotence. These results cast doubt on the validity of BCR measurements of the diagnosis of organic erectile dysfunction due to a neurologic disease. We recorded the BCR in 90 subjects. Nineteen had abnormal BCR latencies. Furthermore, eight of these 19 subjects had normal nocturnal erections, thus confirming the diagnosis of psychogenic impotence. These results cast doubt on the validity of BCR measurements for the diagnosis of organic erectile dysfunction due to a neurologic disease.