Significance of impaired penile tumescence and associated polysomnographic abnormalities in the impotent patient.

Of 15 consecutive patients with secondary impotence 7 (46 per cent) had varied degrees of abnormal nocturnal penile tumescence and 1 or more of the following sleep-associated events: frequent apnea and hypoventilation, myoclonus and a slow but remarkably stable heart rate even during episodes of respiratory impairment. All nocturnal penile tumescence measurements, except circumference change at the glans, were significantly lower than in patients with psychogenic impotence or normal subjects. These findings, not described previously, suggest probable central nervous system etiology of organic impotence in some patients. Skilled nocturnal penile tumescence assessment in conjunction with a comprehensive polysomnographic study is an essential diagnostic procedure in the evaluation of the impotent patient.