Catathrenia is a rare sleep disorder characterised by groaning and prolonged expiration confined to sleep alternating with normal breathing that may occur at all sleep stages. After its first description in 1983 [1], catathrenia was recently introduced into the International Classification of Sleep Disorders [2]. Although the exact pathogenesis remains unknown, catathrenia has been considered a...

BACKGROUND AND OBJECTIVE Studies of the relationship of weight status with timing of puberty in boys have been mixed. This study examined whether overweight and obesity are associated with differences in the timing of puberty in US boys. METHODS We reanalyzed recent community-based pubertal data from the American Academy of Pediatrics' Pediatric Research in Office Settings study in which trai...

Information processing has been suggested to depend on the current state of the brain as well as stimulus characteristics (e.g. salience). We compared processing of salient stimuli (subject's own names [SONs] and angry voice [AV] stimuli) to processing of unfamiliar names (UNs) and neutral voice (NV) stimuli across different vigilance stages (i.e. wakefulness as well as sleep stages N1 and N2) ...

Automatic classification of sleep stages is one of the most important methods used for diagnostic procedures in psychiatry and neurology. This method, which has been developed by sleep specialists, is a time-consuming and difficult process. Generally, electroencephalogram (EEG) signals are used in sleep scoring. In this study, a new complex classifier-based approach is presented for automatic s...

Overnight sleep EEG recorded from 21 derivations was studied for 7 subjects (4 normal and 3 depressive). The multichannel autoregressive model was fitted to all 21 channels simultaneously. Ordinary, multiple and partial coherencies and directed transfer function were estimated for sleep stages and wakefulness. Ordinary coherencies give rather trivial information that coherence decreases with th...

BACKGROUND We investigate the potential usability of a novel in-the-ear electroencephalography recording device for sleep staging. METHODS In one healthy subject we compare simultaneous earelectroencephalography to standard scalp EEG visually and using power spectrograms. Hypnograms independently derived from the records are compared. RESULTS We find that alpha activity, K complexes, sleep ...

OBJECTIVE—Nocturnal hypoglycemia represents an important problem for diabetic patients, which has been primarily attributed to an attenuated hormonal counterregulation during sleep. So far, hypoglycemia counterregulation has been exclusively examined during early nocturnal sleep, although early sleep differs markedly in sleep stage architecture from late sleep. Here, we investigated whether awa...

BACKGROUND Nowadays, sleep quality is one of the most important measures of healthy life, especially considering the huge number of sleep-related disorders. Identifying sleep stages using polysomnographic (PSG) signals is the traditional way of assessing sleep quality. However, the manual process of sleep stage classification is time-consuming, subjective and costly. Therefore, in order to impr...