Sleep and daytime sleepiness in upper airway resistance syndrome compared to obstructive sleep apnoea syndrome. C. Guilleminault, Y. Do Kim, S. Chowdhuri, M. Horita, M. Ohayon, C. Kushida. #ERS Journals Ltd 2001. ABSTRACT: This study has investigated differences in the nocturnal sleep and daytime sleepiness among patients with obstructive sleep apnoea syndrome (OSAS), upper airway resistance (UARS), sleep hypopnoea syndrome, and normal control subjects, using sleep scoring and spectral activity analysis of the electroencephalogram (EEG).Twelve nonobese males with UARS aged 30 -60 yrs were recruited. These subjects were strictly matched for age and body mass index with twelve OSAS patients, 12 sleep hypopnoea syndrome patients, and 12 normal controls, all male. Daytime sleepiness was evaluated using the Epworth Sleepiness Scale (ESS) and the Multiple Sleep Latency Test (MSLT). The macrostructure of sleep was determined using international criteria and spectral analysis of the sleep EEG was obtained from a central lead.The sleep macrostructure of OSAS and UARS patients was significantly different from that of controls. These patients were also sleepier during the daytime than controls. Complaints of tiredness and daytime sleepiness, ESS and MSLT scores were similar in the different patient groups. Mild dysmorphia was present in all three patient groups. However, nocturnal sleep was significantly different among the different groups. OSAS patients had significantly more awake time during sleep than the UARS patients. The spectral activity of the total sleep time of the patient groups also differed significantly from that of controls. When the sleep spectral activity of UARS and OSAS patients were compared, OSAS patients had less slow wave sleep activity than UARS patients. UARS patients had a significantly higher absolute power in the 7 -9 Hz bandwidth than OSAS patients. The absolute delta power over the different sleep cycles was also different between controls and patients, and between UARS and OSAS patients.There are clear differences in the macrostructure and spectral activity of sleep between upper airway resistance and obstructive sleep apnoea syndrome patients, demonstrated by differences in the cortical activity recorded in the central lead during sleep. Despite these nocturnal sleep differences, the tests of subjective daytime sleepiness are not significantly different.

Objective: To study the role of increased sympathetic tone in pathogenesis of hypertension in patients with essential hypertension with neurovascular compression. Methods: Twenty-three patients with essential hypertension, 13 patients with secondary hypertension, and 46 normotensive subjects were investigated. Neurovascular compression was evaluated by MRT. The power spectral components of heart rate variability as indices of autonomic nerve tone were determined to investigate the possibility that sympathetic tone mediates the neurovascular compression-induced increase in blood pressure. Results: Neurovascular compression of the rostral ventrolateral medulla (RVLM) was observed in 70% of essential hypertension group, none of secondary hyperension group and 16% of normotensive group (P Ͻ 0.001). The age-adjusted low-frequency power spectral density (A-PSD) (0.04 to 0.15 Hz), which is an index of

The purpose of this study was to elucidate the agreement of visual scoring of all‐night polysomnographic recordings among many scorers from different laboratories. Ten scorers including the author from different laboratories in Japan scored the same paper recordings of two young male subjects. We calculated the agreement rate for each stage using an epoch by epoch analysis. In both records, the agreement rates for stages 2 and R were high; on the contrary, those for stages 3 and 4 were low. After adding a supplementary definition of high voltage slow wave in deep sleep, we scored the first NREM period of another subject. The mean agreement rate for stage 3 among 10 scorers was significantly higher than those of the two former subjects. However, the agreement for stage 4 did not change so much. This result demonstrates that there is much interrater (laboratory) variability of visual scoring, especially in slow wave sleep. When the result of automatic scoring is compared to that of the visual scoring to evaluate the reliability of automatic scoring, these findings must be considered.

No abstract

Internal stresses in glassy polymer materials arise from two different sources; deviation of polymer conformation from its equilibrium state and change of intersegment distances. These stress components may be separately observed by carrying out simultaneous measurements of tensile stress and birefringence relaxations of polymer films, assuming that they are additive. It is pointed out that the change of intersegment distances occurs first, and conformational deformation is gradually induced if a glassy polymer film is elongated.