Evaluation of erectile dysfunction with the sympathetic skin response in comparison to bulbocavernosus reflex and somatosensory evoked potentials of the pudendal nerve.

Sympathetic skin response (SSR) was investigated in 60 normal subjects (mean age 37.7 +/- 15.9) and 30 patients (mean age 47.2 +/- 12.0) referred from the department of urology for further electrophysiological evaluation of erectile dysfunction (ED). SSR was present in all normal subjects. Mean latency in the lower extremities was 2.16 +/- 0.20 sec. The coefficient of variance for repeated measurements in individual subjects was 10%. The latencies correlated slightly positively with the height of the subjects (r = 0.271, p < 0.05), but not with age. SSR in patients was compared to the bulbocavernosus reflex (BCR) and somatosensory evoked potentials (SSEP) of the pudendal nerve. All patients had a complete urological work-up with evaluation of hormonal function, pharmacotesting and Dopplersonography, as well as pharmacocavernosography and measurement of nocturnal penile tumescence if indicated. Six patients were diagnosed to have functional impotence, 4 dysfunctions were probably of vascular origin, 5 were neurogenic and 15 of the mixed type of vascular and neurogenic origin. Diabetes mellitus was the underlying disease in 14. In the two groups with neurogenic involvement (5 neurogen, 15 mixed) 14 of 20 patients had a pathological BCR, 12 had pathological SSEP and 9 had an absent SSR. Of these 9 patients two showed normal BCR and SSEP. Sensitivity for neurogenic dysfunction was 70% for the BCR, 60% for the BCR and SSEP, but that it detects some patients with erectile dysfunction, in whom other parameters are not pathological.(ABSTRACT TRUNCATED AT 250 WORDS)