Effects of different sleep deprivation protocols on sleep perception in healthy volunteers.

OBJECTIVES: To investigate whether different protocols of sleep deprivation modify sleep perception. METHODS: The effects of total sleep deprivation (TD) and selective rapid eye movement (REM) sleep deprivation (RD) on sleep perception were analyzed in normal volunteers. Thirty-one healthy males with normal sleep were randomized to one of three conditions: (i) normal uninterrupted sleep; (ii) four nights of RD; or (iii) two nights of TD. Morning perception of total sleep time was evaluated for each condition. Sleep perception was estimated using total sleep time (in hours) as perceived by the volunteer divided by the total sleep time (in hours) measured by polysomnography (PSG). The final value of this calculation was defined as the perception index (PI). RESULTS: There were no significant differences among the three groups of volunteers in the total sleep time measured by PSG or in the perception of total sleep time at baseline condition. Volunteers submitted to RD exhibited lower sleep PI scores as compared with controls during the sleep deprivation period (P <0.05). Both RD and TD groups showed PI similar to controls during the recovery period. CONCLUSION: Selective REM sleep deprivation reduced the ability of healthy young volunteers to perceive their total sleep time when compared with time measured by PSG. The data reinforce the influence of sleep deprivation on sleep perception.

Narcolepsy with cataplexy in monozygotic twins.

INTRODUCTION: This paper describes narcolepsy with cataplexy in two monozygotic twin sisters. OBJECTIVE: To clinically illustrate the involvement of neurological, genetic and immunologic systems in narcolepsy. MATERIAL AND METHODS: We performed a restropective study of these patients that were followed in the sleep medicine ambulatory clinic of the Faculdade de Medicina de Ribeirao Preto. RESULTS: These sisters are two of the few cases in the literature concordant for narcolepsy with catalepsy and without a "positive HLA" for narcolepsy. They had a typical clinical course of narcolepsy with cataplexy and attended all the neurophysiological diagnostic criteria for narcolepsy. CONCLUSION: In addition to known possible genetical similarity, this report stresses the role of environmental or unknown genetical factors acting on a specific neuro-imuno-genetical background and resulting in narcolepsy.

Sleep perception in insomniacs, sleep-disordered breathing patients, and healthy volunteers--an important biologic parameter of sleep.

BACKGROUND: The mechanisms involved in sleep perception are not widely known. Therefore, we believe that investigating this phenomenon is the best way to understand some of the mechanisms involved in several sleep disturbances, particularly insomnias. OBJECTIVE: The objective of our study was to evaluate sleep perception in insomniacs, sleep-disordered breathing (SDB) patients, and healthy volunteers. Our hypothesis was that insomniacs have less sleep perception than healthy individuals and patients with sleep respiratory disorders. METHODS: We studied 199 individuals who were divided into the following four groups: (1) insomnia group; (2) patients with sleep-disordered breathing; (3) patients with insomnia complaints and an associated sleep respiratory disorder; and (4) healthy individuals with no sleep complaints. All patients were subjected to polysomnography (PSG) followed by a questionnaire addressing their perception about the previous night's sleep. In addition to analysis of all sleep parameters, we determined sleep perception as the percentage of the ratio between total sleep time perceived by the patient and the total sleep time obtained by PSG. RESULTS: Sleep perception was significantly lower in insomnia patients than in sleep-disordered breathing patients or the normal group. In addition, no significant differences across the four groups were observed in sleep efficiency and total sleep time. CONCLUSIONS: The results showed that the reported sleep perception of insomniacs is lower than that of sleep-disordered breathing patients or normal individuals. We believe that sleep perception is as important as other commonly measured parameters, such as sleep efficiency.