Erectile dysfunction in narcoleptic patients.

Many male narcoleptic patients complain of erectile dysfunction related to chemotherapy, and some find it so distressing that they fail to continue treatments. This is a potentially dangerous situation. We studied the erectile capabilities of 28 narcoleptic men who had complaints of erectile dysfunction with our objective sleep laboratory measurement of nocturnal penile tumescence (NPT) for diagnostic workup. We found that while short REM latency, a classic indicator of narcolepsy, was present in all patients, NPT, which is associated with REM sleep, did not coincide with the short REM latencies in about half the patients. This may be partially due to the fact that first-cycle REM is often not accompanied by NPT episodes (even in the control population). We also found that, in a few cases, the patients' subjective beliefs about their erectile capacity tended to underestimate our measurements. The patients receiving drug treatment already had some vasculogenic or neurogenic genital impairment, which probably made them more vulnerable to the effects of the drugs. Patients who had none of these complications showed similar erectile impairment under the influence of medication. Additionally, we found unique manifestations of the disease in three drug-free patients; one had cataplectic attacks upon arousal, and two had unexplained erectile impairment.