RESUMEN
PURPOSE: To determine whether sleep-related erections(SREs) occur during chronic vegetative state and if so, to investigate what factors are involved. MATERIALS AND METHODS: Twenty-six men in a vegetative state aged 16~65 were selected. Exclusion criteria were the lack of informed consent, mean blood pressure under 90/60 mmHg during last 3 days, erectile dysfunction before brain injury, and a history of any anti-androgen treatment. Serum testosterone, albumin, sex hormone binding globulin(SHBG), and dehydroepiandrosterone sulfate(DHEAS) were assayed, and bioavailable testosterone(cBT) and free testosterone(cFT) were calculated. Nocturnal penile erections were counted and evaluated using the Rigiscan device for72 hours. Data on the number of erections, erection duration, minimal and maximal base tumescence, minimal and maximal tip tumescence, and base and tip rigidity were taken. RESULTS: SREs were noted in 25 patients. The mean erection number was 4.65+/-3.93(1~15), and the mean erection duration was 128.85+/-46.86 minutes(0~478.5). SREs were negatively correlated with age(r=-0.445, p<0.05), systolic BP(r=-0.394, p<0.05) and diastolic BP(r=-0.403, p<0.05), but positively correlated with DHEAS(r=0.395, p<0.05). SREs were not correlated with total testosterone, cBT or cFT. CONCLUSIONS: These preliminary findings suggest that SREs are a normal occurrence in vegetative patients. They contribute to penile blood perfusion if the supraspinal erection control center is intact and serum testosterone level is above the minimum required for SREs.