Journal of sleep research
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Journal of sleep research · Sep 2006
Night-to-night alterations in sleep apnea type in patients with heart failure.
In patients with heart failure, apnea type can shift overnight from mainly obstructive to mainly central in association with reductions in PCO(2) and increases in periodic breathing cycle length, indicative of a fall in cardiac output. We hypothesized that the predominant apnea type could also vary from one night to another in association with alterations in PCO(2) and cycle length. ⋯ In contrast, in both the stable central (n = 8, duration between sleep studies 11.9 +/- 5.3 months) and the stable obstructive (n = 8, duration between studies 6.9 +/- 5.2 months) sleep apnea groups, neither PCO(2) nor cycle length changed significantly between the baseline and follow-up sleep studies. We conclude that in some patients with heart failure, OSA and CSA are part of a spectrum of periodic breathing that can shift over time in association with alterations in PCO(2), cycle length and probably cardiac function.
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Journal of sleep research · Sep 2006
Sleep bruxism is associated to micro-arousals and an increase in cardiac sympathetic activity.
Sleep bruxism (SB) subjects show a higher incidence of rhythmic masticatory muscle activity (RMMA) than control subjects. RMMA is associated with sleep micro-arousals. This study aims to: (i) assess RMMA/SB episodes in relation to sleep cycles; (ii) establish if RMMA/SB and micro-arousals occur in relation to the slow wave activity (SWA) dynamics; (iii) analyze the association between RMMA/SB and autonomic cardiac activity across sleep cycles. ⋯ The cross-correlation plot revealed that SWA decreases following SB onset (P
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Journal of sleep research · Dec 2005
CAP and arousals are involved in the homeostatic and ultradian sleep processes.
There is growing evidence that cyclic alternating pattern (CAP) and arousals are woven into the basic mechanisms of sleep regulation. In the present study, the overnight sleep cycles (SC) of 20 normal subjects were analyzed according to their stage composition, CAP rate, phase A subtypes and arousals. Individual SC were then divided into 10 normalized temporal epochs. ⋯ SA showed an exponential decline across the successive SC, according to the homeostatic process. In contrast, the distribution of FA was not influenced by the order of SC, with periodic peaks of FA occurring before the onset of REM sleep, in accordance with the REM-on switch. The dynamics of CAP and arousals during sleep can be viewed as an intermediate level between cellular activities and macroscale EEG phenomena as they reflect the decay of the homeostatic process and the interaction between REM-off and REM-on mechanisms while are slightly influenced by circadian rhythm.
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Journal of sleep research · Dec 2005
Case ReportsAgrypnia excitata in a patient with progeroid short stature and pigmented Nevi (Mulvihill-Smith syndrome).
We report the video-polysomnographic sleep characteristics of a 25-year-old woman with the Mulvihill-Smith syndrome, a rare clinical condition characterized by progeria-like aspect, peculiar multiple pigmented nevi, low stature, and cognitive impairment. Among the various exams, two overnight video-polysomnographic recordings were carried out; moreover, cerebral MRI and molecular analysis of the prion protein gene (PRNP) were also performed. ⋯ Our clinical and neurophysiological study seems to indicate that a particular condition of severe sleep disruption, similar to some extent to that reported in the fatal familial insomnia and in the Morvan fibrillary chorea, which has been indicated as Agrypnia Excitata in recent literature, might be associated with the Mulvihill-Smith syndrome. The inclusion of a detailed study on the sleep characteristics of eventual additional patients will certainly help our understanding of this rare condition.