Assessment of local sympathetic function in patients with erectile dysfunction.

Fifty men with erectile dysfunction (ED) were urologically investigated for autonomic deficit by evaluation of the sympathetic skin response at the penis. They were additionally subjected to thorough urological, vascular, psychiatric and neurological examinations, and well-established neurophysiological tests of the somatosensory, sympathetic, and parasympathetic function. Patients with clinical evidence of neurological deficit showed abnormal results (68%) in at least one test of the autonomic nervous system. The sympathetic skin response at the penis was absent in 11 cases (37%) with clinical evidence of neuronal aetiology of the erectile dysfunction and was normal in all cases with positive evidence of a psychiatric origin of erectile dysfunction and no clinical indication of a neuronal deficit. Moreover, the sympathetic skin response at the penis was abnormal in three cases with normal results in the other neurophysiological tests. The results emphasize that the local sympathetic skin response at the penis is a useful extension of autonomic testing in ED patients since this method tests local sympathetic pathways and is sometimes the only evidence for autonomic deficit. From a clinical viewpoint, the sympathetic skin response at the penis is a very simple and time-saving neurophysiological method suitable for clinical routine and also for the investigation of outpatients.