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 activity (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 across sleep cycles. DESIGN: N/A SETTING: N/A PATIENTS: A polysomnographic study was performed on 15 adult sleepwalkers and 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 decrease in SWA across NREM cycles. Sleepwalkers had a significantly lower level 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.