Sleep induction for EEG revisited: technical note

Forty-two patients each were randomly assigned in equal numbers to receive either zolpidem or secobarbital for sleep EEG recording. Three groups were compared; zolpidem, secobarbital and a control group of patients who drowsed spontaneously. All patients were evaluated before and immediately after the EEG and several hours later with measures of anxiety, perceptual-motor performance, locomotion, and subjective judgments of sleepiness. EEG response to standard activation procedures, signs of drowsiness and sleep and overall diagnoses were compared among the three groups. No differences emerged in demographic measures, psychiatric diagnoses, current drug treatment and experience with hypnotics. There were no statistically significant differences among the three groups or between the patients receiving the hypnotics on the anxiety performance and locomotion measures or degree of alertness. As a result of the experimental design, the unmedicated control patients showed EEG signs of drowsiness and sleep significantly sooner than patients receiving hypnotics. They also showed more slow or paroxysmal activity in response to hyperventilation, which may have been due to their greater effort. These results led us to retain secobarbital as the hypnotic for EEG sleep, mainly for economic reasons.