Quantitative assessment of nocturnal penile tumescence and rigidity in normal men using a home monitor.

Current methods now permit the measurement of nocturnal penile tumescence and rigidity (NPTR) in men with erectile dysfunction. But the relationship of rigidity to tumescence and the changes in rigidity with age have not been defined in normal men. Accordingly, the authors assessed NPTR in 47 normal men using a portable, take-home monitor (Rigiscan). Penile tumescence time was found to decrease with advancing age (p less than 0.05), whereas the number of erectile episodes and penile rigidity did not significantly change with age for men in the third through sixth decades (p less than 0.05). Using area-under-the-curve as an integrated measure of amplitude and duration, significant correlations between tumescence and rigidity (p less than 0.001), and between tip and base measurements (p less than 0.001) were found. With these normative data, prospective studies should determine the sensitivity and specificity of various NPTR parameters in the diagnosis of erectile dysfunction.