Bulbocavernosus reflex to somatic and visceral nerve stimulation in normal subjects and in diabetics with erectile impotence.

Bulbocavernosus reflex to stimulation of the vesicourethral junction and glans penis was recorded in 14 normal controls and 24 diabetic men complaining of erectile impotence. In all normal subjects the bulbocavernosus reflex to stimulation of these sites could be obtained, and mean latencies were 59.2 +/- 8.0 msec. and 33.3 +/- 3.7 msec., respectively (p less than 0.00001). A total of 66 per cent of the diabetics (16 patients) exhibited abnormal (delayed or absent) bulbocavernosus reflex to stimulation of the vesicourethral junction, while only 12.5 per cent (3 patients) had delayed response to glans penis stimulation. The latter tended to remain within normal limits, although the mean latency was significantly different from that of normal subjects (p less than 0.05). Abnormalities of the bulbocavernosus reflex to stimulation of the vesicourethral junction correlated strongly with the presence of peripheral and autonomic neuropathy, diabetes and organogenic impotence. Our results indicate that this is an informative test for the evaluation of visceral afferents arising from the bladder neck and, hence, in the differential diagnosis of organogenic versus psychogenic erectile impotence.