Background and Hypothesis Cognitive impairment is a core feature of schizophrenia that worsens with aging and interferes with quality of life. Recent work identifies sleep as an actionable target to alleviate cognitive deficits. Cardinal non-rapid eye movement (NREM) sleep oscillations such as sleep spindles and slow oscillations are critical for cognition. People living with schizophrenia (PLWS) and their first-degree relatives have a specific reduction in sleep spindles and an abnormality in their temporal coordination with slow oscillations that predict impaired memory consolidation. While NREM oscillatory activity is reduced in typical aging, it is not known how further disruption in these oscillations contributes to cognitive decline in older PLWS. Another understudied risk factor for cognitive deficits among older PLWS is obstructive sleep apnea (OSA) which may contribute to cognitive decline. Study Design We conducted a narrative review to examine the published literature on aging, OSA, and NREM sleep oscillations in PLWS. Study Results Spindles are propagated via thalamocortical feedback loops, and this circuitry shows abnormal hyperconnectivity in schizophrenia as revealed by structural and functional MRI studies. While the risk and severity of OSA increase with age, older PLWS are particularly vulnerable to OSA-related cognitive deficits because OSA is often underdiagnosed and undertreated, and OSA adds further damage to the circuitry that generates NREM sleep oscillations. Conclusions We highlight the critical need to study NREM sleep in older PWLS and propose that identifying and treating OSA in older PLWS will provide an avenue to potentially mitigate and prevent cognitive decline.

中文翻译：

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与年龄相关的睡眠变化及其对老年精神分裂症患者认知能力下降的影响：一项批判性回顾

背景和假设认知障碍是精神分裂症的核心特征，随着年龄的增长而恶化并干扰生活质量。最近的研究将睡眠确定为缓解认知缺陷的可行目标。主要非快速眼动 (NREM) 睡眠振荡（例如睡眠纺锤波和慢振荡）对于认知至关重要。精神分裂症患者（PLWS）及其一级亲属的睡眠纺锤波有特定的减少，并且他们的时间协调异常，伴有缓慢的振荡，这预示着记忆巩固受损。虽然 NREM 振荡活动在典型的衰老过程中会减少，但尚不清楚这些振荡的进一步破坏如何导致老年 PLWS 的认知能力下降。老年 PLWS 中认知缺陷的另一个未被充分研究的危险因素是阻塞性睡眠呼吸暂停 (OSA)，它可能会导致认知能力下降。研究设计 我们进行了叙述性回顾，以检查关于 PLWS 中衰老、OSA 和 NREM 睡眠振荡的已发表文献。研究结果 纺锤体通过丘脑皮质反馈回路传播，结构和功能 MRI 研究揭示，该回路在精神分裂症中表现出异常的超连接性。虽然 OSA 的风险和严重程度随着年龄的增长而增加，但老年 PLWS 特别容易受到 OSA 相关认知缺陷的影响，因为 OSA 往往诊断不足和治疗不足，而且 OSA 进一步损害了产生 NREM 睡眠振荡的电路。结论 我们强调研究老年 PWLS 中 NREM 睡眠的迫切需要，并提出识别和治疗老年 PLWS 中的 OSA 将为潜在减轻和预防认知能力下降提供途径。