Value of nocturnal penile tumescence and rigidity (NPTR) recording in impotent patients with multiple sclerosis.

The etiology of impotence in patients with multiple sclerosis (MS) is difficult to assess due to the possibility of normal nocturnal penile tumescence and rigidity (NPTR) recording despite neurologic involvement. Sixteen patients with MS and impotence were studied with Rigiscan, cavernous artery doppler, neurophysiological tests and intracavernous injection of PGE1. When more restrictive criteria of normality than usual are used for Rigiscan (rigidity > or = 80% and/or duration > 30 minutes), an inverse relationship between NPTR recording and sexuality score or PGE1 dose is reported. No significant difference is noted for neurophysiological tests. With such criteria, Rigiscan alone or combined with intracavernous PGE1 is a valuable means to differentiate neurogenic from psychogenic impotence in MS patients. Neurophysiological tests are of limited clinical value.