[Electrophysiologic diagnosis in erectile dysfunction]

So far, electrophysiological examinations have rarely been used in the diagnosis of erectile dysfunction (ED) mainly because the methods available only allow somatic neuron pathways to be examined whose relevance for the mainly autonomically controlled crection is evaluated differently. At present, impaired penile nerve supply as the possible cause of ED can only be evaluated through neurophysiological screening of the somatic and autonomic pathways of the pelvic floor, and not just by one simple method. Diagnosing ED should include testing of motoric efferences through electroneurography of the pudendal nerve and electromyography of the external anal sphincter and the urethral sphincter. Sensitive afference is tested with somatosensory evoked potentials of the pudendal nerve. New methods that are available for the examination of autonomic pathways are the penile sympathetic skin response and the EMG of the corpus cavernosum. Together with the other electrophysiological examinations, they allow neurogenic causes to be determined and differentiate not only between central and peripheric lesions, but also between acute and chronic changes. Prognosis can also be estimated. A crucial diagnostic deficit is the fact that it is still not possible to test the parasympathetic system directly.