The effects on sleep of two well known hypnotics, lormetazepam and zolpidem, during experimentally induced environmental noise were compared with placebo. In a double-blind, crossover study, 12 normal volunteers were subjected to prerecorded traffic noise with a mean noise level of 52 dB(A) and peaks to 77 dB(A) continuously for 8 hours in bed. Both hypnotics increased total sleep time, predominantly stage 2 sleep. A significant decrease in the number of sleep stage transitions, arousals, and awakenings longer than 3 minutes was found only with lormetazepam. No significant effects on rapid eye movement (REM) and slow wave sleep were observed. Latencies to persistent sleep and REM sleep onset were not different for either active treatment compared with placebo. Only after lormetazepam was performance on the morning reaction time test significantly affected. However, no differences were found in the subjective sleep quality and alertness ratings. Changes in the distribution of sleep stages throughout the night were related to the elimination half-life characteristics of the hypnotics, but few trends were detected. Both the protective properties against environmental noise of the hypnotics studied and the validity of the model of induced sleep disturbance in evaluating hypnotic agents are discussed.

No abstract

Snoring is a common phenomenon and a primary symptom in obstructive sleep apnea syndrome, a sleep-related breathing disorder in which neuropsychological function is reported to be impaired. The first purpose of the present study was to compare cognitive and motor function in 25 heavy nonapneic snorers and 26 sleep apneics. As the basis for impairments in heavy nonapneic snorers is still unclear, the influence of nighttime breathing disturbances and morning alertness, respectively, on daytime performance was evaluated too. Nonapneic snorers exhibit more slow wave sleep and tend to have fewer changes in sleep stage than sleep apnea patients, but values for other sleep variables are similar. Snorers also show comparable alertness. Deficits in immediate visual memory and in visuospatial reasoning are not found. However, there are some indications that snorers show decreased manual dexterity and eye-hand coordination for the nonpreferred hand and that they have deficits in focused attention. In addition, snorers may show difficulties in finger-tapping speed. These performance measures tend to be associated with reduced morning alertness, except for the score on focused attention which has a tendency to be related to the nocturnal breathing disturbances.

Neuropsychological functioning is reported to be impaired in patients suffering from obstructive sleep apnea syndrome (OSAS). This syndrome is characterized by nocturnal respiratory disturbances, blood oxygen desaturations, sleep fragmentation, and excessive daytime sleepiness. Opinions arc divided concerning the exact relationship between the observed cognitive deficits, nocturnal hypoxia, sleep disruption, and impaired daytime alertness. In the present study, morning neuropsychological function of 26 moderate to severe middle-aged sleep apneics is compared to that of 22 primary insomniacs. There were no performance differences on a range of neuropsychological tests among the two patient groups. In addition, the data suggest that morning alertness impairment, which is closely associated with a lack of slow wave sleep (SWS) and rapid eye movement (REM) sleep, is of major importance in inducing poorer cognitive performance in patients with moderate to severe sleep apnea. (JINS, 1996, 2,306–314.)

In this single-blind study the sedative and hypnotic properties of buspirone, a nonbenzodiazepine anxiolytic, were investigated in 8 anxious outpatients. Polysomnographic recordings were gathered during baseline, at the start of active medication, after 3 weeks of treatment and one night after discontinuing treatment. Daytime alertness was measured using the Multiple Sleep Latency Test and performance tests. The effects of buspirone on sleep structure were minimal and of no clinical consequence. Subjectively, the patients reported improved sleep quality. There were no effects on daytime alertness at the beginning, after 3 weeks or at sudden discontinuation of the medication. It is concluded that buspirone does not have a sedative or hypnotic effect in anxiety patients.