Dynamics of slow-wave activity during the NREM sleep of sleepwalkers and control subjects

Study Objective: To compare the number and distribution of awakenings from slow-wave sleep (SWS) and both the power and dynamics of EEG slow-wave acti vity (SWA) in sleepwalkers and controls. Somnambulism is considered to be a disorder of arousal from NREM sleep and related to anomalous SWS and SWA. Power spectral analyses have never been used to quantify patients' SWA acro ss sleep cycles. Design: N/A Setting: N/A Patients: A polysomnographic study was performed on 15 adult sleepwalkers a nd 15 age- and sex-matched controls. Interventions: N/A Measurements & Results: Sleepwalkers had a significantly greater number of awakenings from SWS than did control subjects. Controls showed a greater de crease in SWA across NREM cycles. Sleepwalkers had a significantly lower le vel of SWA during the first NREM period, where most awakenings take place. Conclusion: Sleepwalkers appear to suffer from an abnormality in the neural mechanisms responsible for the regulation of SWS.