Role of penile nocturnal tumescence and rigidity measurement in the diagnosis of erectile impotence.

Reviewing a group of 100 patients undergoing nocturnal penile tumescence and rigidity measurement (NPTR), we tried to define normal values and compared these results with those of other authors. We also tried to answer two important questions: Is an abnormal NPTR registration always a proof of biogenic impotence? Is a normal NPTR always a proof of psychogenic impotence?