Not true about nocturnal penile tumescence is -: (A) Totals about 100 min / night, (B) Normal phenomenon, (C) Occurs in NREM sleep, (D) Can be used to distinguish between psychological or organic impotence
Answer is C. Nocturnal penile tumescence occurs in REM sleep. It is a normal phenomenon and occurs for 80-120 minutes per night. It can differentiate psychogenic impotence from organic impotence.