Descartes and His Peculiar Sleep Pattern.

Rene Descartes (1596-1650) was a mathematician, philosopher, and scholar, whose work set a foundation for modern science. Among other interests, he focused on locating the "core and the seat of the soul" and concluded that the pineal gland was such a structure. Recent scientific findings validate Descartes' deep interest in pineal gland, appreciating its role as part of the circadian rhythm system. On the other hand, the biographical information suggests that Descartes had an aberration of the circadian rhythm (delayed sleep phase). Coincidentally, this meant that one of the most important things in his private life and one of the most significant areas of his research intersected in an overlooked way.

Serbian translation of the 20-item Toronto Alexithymia Scale: psychometric properties and the new methodological approach in translating scales.

INTRODUCTION: Since inception of the alexithymia construct in 1970's, there has been a continuous effort to improve both its theoretical postulates and the clinical utility through development, standardization and validation of assessment scales. OBJECTIVE: The aim of this study was to validate the Serbian translation of the 20-item Toronto Alexithymia Scale (TAS-20) and to propose a new method of translation of scales with a property of temporal stability. METHODS: The scale was expertly translated by bilingual medical professionals and a linguist, and given to a sample of bilingual participants from the general population who completed both the English and the Serbian version of the scale one week apart. RESULTS: The findings showed that the Serbian version of the TAS-20 had a good internal consistency reliability regarding total scale (alpha=0.86), and acceptable reliability of the three factors (alpha=0.71-0.79). CONCLUSION: The analysis confirmed the validity and consistency of the Serbian translation of the scale, with observed weakness of the factorial structure consistent with studies in other languages. The results also showed that the method of utilizing a self-control bilingual subject is a useful alternative to the back-translation method, particularly in cases of linguistically and structurally sensitive scales, or in cases where a larger sample is not available. This method, dubbed as 'forth-translation' could be used to translate psychometric scales measuring properties which have temporal stability over the period of at least several weeks.

Sleep-laughing--hypnogely.

OBJECTIVE: To explain relatively common phenomenon of laughing during sleep and help to better define criteria for differentiating between physiological and pathological sleep-laughing. METHODS: Observational study of patients who underwent a sleep assessment in a referential tertiary health facility. RESULTS: A total of ten patients exhibited sleep laughing, nine of whom had episodes associated with rapid eye movement (REM) sleep. Also, in one of the patients sleep-laughing was one of the symptoms of REM sleep Behaviour Disorder, and in another patient sleep-laughing was associated with NREM sleep arousal parasomnia. CONCLUSION: The collected data and review of literature suggests that hypnogely in majority of the cases presents as a benign physiological phenomenon related to dreaming and REM sleep. Typically, these dreams are odd, bizarre or even unfunny for a person when awake. Nevertheless, they bring a sense of mirth and a genuine behavioural response. In a minority of cases, sleep-laughing appears to be a symptom of neurological disorders affecting the central nervous system. In these patients the behavioural substrate differs when compared to physiological laughing, and the sense of mirth is usually absent.

[Principles of diagnosis of apnea in sleep].

One of the most important fields in sleep medicine is that of respiratory disorders in sleep. There was a steady progress in a development of new diagnostic methods and procedures, particularly after the introduction of portable apnea screening devices. The review provides update on techniques and procedures in respect to the diagnosis of sleep apnoea. Current trends are discussed, including the increasing role of portable devices and at-home monitoring in the screening and diagnostic process. A comparison between the procedures is discussed, as well as the polysomnographic examples of different types of studies (Type 1 to Type 4, attended v. non-attended).

Sexual behaviour in sleep: an internet survey.

The objective of the study was to provide further information related to newly described parasomnia variant, Sexual Behaviour in Sleep (SBS, sexsomnia). Previous studies dealt with selected population, typically middle-aged males, featuring extensive medico-legal exposure. At the same time, an anecdotal evidence suggested higher involvement of younger population, and skew towards balance between genders comparable to those seen in other non-Rapid Eye Movement (NREM) sleep parasomnias. The epidemiological information regarding this condition is still virtually non-existent. In order to sample this difficult-to-reach population, a 28-item Internet survey was posted on the sexsomnia reference site and the link was also sent to prospective respondents (mostly registered visitors to this site). The respondents were able to complete the survey anonymously, which resulted in a need for the screening of bogus and duplicate results. At the end, a total of 219 validated responses were collected and analysed. The results showed greater representation of females (31% of the total number), and wider age distribution (mean age of 30.4 years). The respondents typically reported multiple sexsomnia episodes, in most cases precipitated by body contact, stress and fatigue. Relatively small number of respondents reported involvement of legal authorities (8.6% of males and 3% of females) and participation of minors in their sexsomnia (6% of the total sample). In spite of known limitations of such surveys, the study provided much needed insight into this complex nocturnal behaviour. It confirmed the anecdotal evidence about the gender and age distribution, and provided information on some key features, such as precipitating factors, type of behaviour, medication use, personal medical history and medico-legal aspects.

Positive sleep state misperception - a new concept of sleep misperception.

OBJECTIVES: To better define the concept of sleep misperception and analyse a category of patients who overestimate their sleep. At present, a condition of underestimation of sleep is classified as paradoxical insomnia. Overestimation of sleep has also been reported in the past, with no clear reference to corresponding polysomnographic (PSG) findings or its clinical significance. PATIENTS AND METHODS: Patients were recruited from the general population undergoing a PSG assessment for a cross-sectional retrospective study in a sleep clinic affiliated with a tertiary health center. RESULTS: A group of patients who overestimated their sleep had mostly non-discriminating PSG findings when compared to patients who underestimated their sleep, and correct estimators. The only parameters that were significantly different were objective sleep duration and efficiency, and, importantly, respective multiple sleep latency test (MSLT) results. The patients who overestimated their sleep had a mean MSLT result of 7.8 min, which indicates moderate daytime sleepiness. Patients who underestimated their sleep and correct estimators had the respective MSLT results of >10 min, making a statistically significant difference. CONCLUSION: The authors identified a condition opposite the previously described sleep underestimation, and named it 'positive sleep state misperception' (PSSM). The condition is characterised by a gross overestimation of sleep. Inadequate sleep results in a clinically significant excessive daytime sleepiness, which patients were not able to predict. The authors propose a new model that incorporates both ends of the sleep misperception spectrum.

Sleep-disordered breathing, cardiac arrhythmia, and panic disorder.

Sleep-disordered breathing often presents as a cardiac or psychiatric problem. Such presentation may lead to suboptimal diagnostic and therapeutic decisions. The authors present a case in which a patient's condition improved only after the primary disorder was diagnosed and properly managed.

REM sleep behaviour disorder in a child with Tourette's syndrome.

PURPOSE: To describe an association of Tourette's syndrome with rapid eye movement sleep behaviour disorder (RBD) in a prepubescent boy. METHODS: A four year longitudinal single-case study. RESULTS: The co-existence of Tourette's syndrome and RBD was confirmed after polysomnographic studies using the standard criteria. The authors propose possible overlap in the pathophysiological mechanisms underlying the two disorders.

Sexsomnia--a new parasomnia?

OBJECTIVE: To describe a distinct parasomnia involving sexual behaviour, which we have named sexsomnia. METHOD: We have used a case series as a basis for the description of sexsomina. RESULTS: Eleven patients with distinct behaviours of the sexual nature during sleep are described. The features in common with other nonrapid eye movement arousal parasomnias, such as sleepwalking are documented. Some patients had simply been referred to a tertiary sleep clinic for investigation of unrelated sleep problems. A small number had been involved in medicolegal issues. Sexsomnia has some distinct features that separate it from sleepwalking. The automatic arousal is more prominent, motor activities are relatively restricted and specific, and some form of dream mentation is often present. CONCLUSIONS: A significant number of patients with this unusual parasomnia behaviour were identified only after specific questions were asked, suggesting that the behaviour is more common than previously thought.