Study objectives: To determine whether sleep-related erections occur in veg
etative state and if so, to investigate their relationship with rapid eye m
ovement (REM) sleep.
Design: N/A
Setting: Major rehabilitation hospital.
Patients: Nine male patients in vegetative state aged 17-40 years.
Interventions: Continuous 24-hour polysomnographic recordings including pen
ile circumferencial changes.
Measurements and Results: Sleep-related erection episodes (SREe's) were not
ed in all nine patients, ranging in number from 1-7/24 hr (average 4.4+2.4)
and lasting 6 to 50 min (average 22.0+5.7 min). The number of REM periods
(REMp's) ranged from 4-11 (average 6.6+2.5) and lasted for 1.0 to 44.0 min
(average 16.0+6.6 min). Ninety-five percent of the SREe's recorded were ass
ociated with REMp's, usually (76.3%) appearing simultaneously with the REMp
or soon thereafter; 64.6% of the REMp's were associated with SRE's. For bo
th the nocturnal and diurnal periods, there were more REMp's with SREe's th
an without, and the REMp's associated with SREe's were of longer duration (
by 25.5% and 28.4%, respectively). There were no statistically significant
differences for any of the REMp or SREe parameters between the recovered an
d nonrecovered patients.
Conclusions: The sleep-related erection characteristics of patients in vege
tative state are similar to those of normal individuals. These findings may
have implications for the assessment of the reorganization of REM sleep du
ring recovery from vegetative state and may further help in our understandi
ng of the pathophysiology of vegetative state. More studies are needed in l
arger groups of patients.