Cyclic alternating pattern in obstructive sleep apnea: A preliminary study

Abstract

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Obstructive sleep apnea and multiple facets of a neuroinflammatory response: a narrative review

“…One of the important unresolved questions in the sleep medicine is whether its second most prevalent sleep disorder, OSA, may indeed also lead to inflammatory responses in the brain (5,6,42,43). This is of particular note as neuroinflammation has been argued to act as a shared archetypal mechanism in the pathogenesis of Alzheimer's disorder (AD), depression and several other major neurologic and psychiatric disorders with which OSA appears to share a complex bidirectional link (6,42,44).…”

“…This is of particular note as neuroinflammation has been argued to act as a shared archetypal mechanism in the pathogenesis of Alzheimer's disorder (AD), depression and several other major neurologic and psychiatric disorders with which OSA appears to share a complex bidirectional link (6,42,44). Our group has long argued that accumulating data does suggest that neuroinflammatory process occurs in OSA, and that it drives specific structural and behavioural changes known to afflict some susceptible OSA patients (42,43,(45)(46)(47)(48)(49). More recently, we have been able to demonstrate that under OSA-like conditions in rodents, the neuroinflammatory response is indeed instigated in the forebrain and the septal nuclei regions, important cholinergic regions of the brain, with a later widespread and marked chronic component.…”

Development and assessment of a risk prediction model for moderate-to-severe obstructive sleep apnea

“…A cyclic EEG alteration occurs during NREM, namely the cyclic alternating pattern (CAP), which reflects the microstructure of sleep and has a crucial role in establishing and maintaining sleep integrity (Terzano and Parrino, 2000;Smerieri et al, 2007). The CAP represents an adaptive state of persistent arousal instability that oscillates between higher levels of arousal and activation (stage A) and lower levels of arousal and deactivation (stage B) (Parrino et al, 2012;Gnoni et al, 2021). CAP and arousal are fundamental mechanisms of sleep regulation, with subtype A1 contributing to the accumulation and consolidation of deep slow-wave sleep (SWS), while subtypes A2 and A3 attenuate sleep and lead to episodes of REM sleep or arousal (Terzano et al, 2005).…”

“…CAP and arousal are fundamental mechanisms of sleep regulation, with subtype A1 contributing to the accumulation and consolidation of deep slow-wave sleep (SWS), while subtypes A2 and A3 attenuate sleep and lead to episodes of REM sleep or arousal (Terzano et al, 2005). Studies have shown that CAP subtype A1 predominates in the mild OSA, while CAP subtypes A2 and A3 predominate in patients with moderate-to-severe OSA (Gnoni et al, 2021). In patients with mild OSA, CAP A1 subtypes may enhance sleep continuity, whereas, in moderate-to-severe OSA, there may be a loss of compensation of these sleep stabilization mechanisms and more invasive CAP fluctuations disrupting sleep circuits (Gnoni et al, 2021).…”

“…Studies have shown that CAP subtype A1 predominates in the mild OSA, while CAP subtypes A2 and A3 predominate in patients with moderate-to-severe OSA (Gnoni et al, 2021). In patients with mild OSA, CAP A1 subtypes may enhance sleep continuity, whereas, in moderate-to-severe OSA, there may be a loss of compensation of these sleep stabilization mechanisms and more invasive CAP fluctuations disrupting sleep circuits (Gnoni et al, 2021). Thus, compared to patients with mild OSA, patients with moderate-to-severe OSA constantly experience sleep fragmentation, producing physical symptoms such as drowsiness and fatigue, as well as psychological symptoms such as stress (Bardwell et al, 2000;Santos et al, 2017).…”