Boord Monique S, Feuerriegel Daniel, Coussens Scott W, Davis Daniel H J, Psaltis Peter J, Garrido Marta I, Bourke Alice, Keage Hannah A D
Cognitive Ageing and Impairment Neurosciences Laboratory, Justice and Society, University of South Australia, Adelaide, 5072, South Australia, Australia.
College of Education, Psychology and Social Work, Flinders University, Adelaide, 5042, South Australia, Australia.
Brain Commun. 2024 Sep 5;6(5):fcae298. doi: 10.1093/braincomms/fcae298. eCollection 2024.
Delirium is a common and acute neurocognitive disorder in older adults associated with increased risk of dementia and death. Understanding the interaction between brain vulnerability and acute stressors is key to delirium pathophysiology, but the neurophysiology of delirium vulnerability is not well defined. This study aimed to identify pre-operative resting-state EEG and event-related potential markers of incident delirium and its subtypes in older adults undergoing elective cardiac procedures. This prospective observational study included 58 older participants (mean age = 75.6 years, SD = 7.1; 46 male/12 female); COVID-19 restrictions limited recruitment. Baseline assessments were conducted in the weeks before elective cardiac procedures and included a 4-min resting-state EEG recording (2-min eyes open and 2-min eyes closed), a 5-min frequency auditory oddball paradigm recording, and cognitive and depression examinations. Periodic peak power, peak frequency and bandwidth measures, and aperiodic offsets and exponents were derived from resting-state EEG data. Event-related potentials were measured as mean component amplitudes (first positive component, first negative component, early third positive component, and mismatch negativity) following standard and deviant auditory stimuli. Incident delirium occurred in 21 participants: 10 hypoactive, 6 mixed, and 5 hyperactive. Incident hyperactive delirium was associated with higher pre-operative eyes open ( = 0.045, = 1.0) and closed ( = 0.036, = 1.0) aperiodic offsets. Incident mixed delirium was associated with significantly larger pre-operative first positive component amplitudes to deviants ( = 0.037, = 1.0) and larger third positive component amplitudes to standards ( = 0.025, = 1.0) and deviants ( = 0.041, = 0.9). Other statistically non-significant but moderate-to-large effects were observed in relation to all subtypes. We report evidence of neurophysiological markers of delirium risk weeks prior to elective cardiac procedures in older adults. Despite being underpowered due to COVID-19-related recruitment impacts, these findings indicate pre-operative dysfunction in neural excitation/inhibition balance associated with different delirium subtypes and warrant further investigation on a larger scale.
谵妄是老年人常见的急性神经认知障碍，与痴呆和死亡风险增加相关。了解脑易损性与急性应激源之间的相互作用是谵妄病理生理学的关键，但谵妄易损性的神经生理学尚未明确界定。本研究旨在确定择期心脏手术老年患者术后谵妄及其亚型的术前静息态脑电图和事件相关电位标志物。这项前瞻性观察性研究纳入了58名老年参与者（平均年龄=75.6岁，标准差=7.1；46名男性/12名女性）；新冠疫情限制导致招募受限。在择期心脏手术前几周进行基线评估，包括4分钟静息态脑电图记录（2分钟睁眼和2分钟闭眼）、5分钟频率听觉oddball范式记录以及认知和抑郁检查。从静息态脑电图数据中得出周期性峰值功率、峰值频率和带宽测量值，以及非周期性偏移和指数。事件相关电位通过标准和异常听觉刺激后的平均成分振幅（第一个正成分、第一个负成分、早期第三个正成分和失配负波）来测量。21名参与者发生了术后谵妄：10名活动减退型、6名混合型和5名活动亢进型。术后活动亢进型谵妄与术前睁眼（P=0.045，β=1.0）和闭眼（P=0.036，β=1.0）时较高的非周期性偏移相关。术后混合型谵妄与术前对异常刺激的第一个正成分振幅显著增大（P=0.037，β=1.0）以及对标准刺激（P=0.025，β=1.0）和异常刺激（P=0.041，β=0.9）的第三个正成分振幅增大相关。在所有亚型方面还观察到其他统计学上无显著意义但为中度至高度的效应。我们报告了老年患者择期心脏手术前数周谵妄风险神经生理标志物的证据。尽管由于新冠疫情相关的招募影响样本量不足，但这些发现表明与不同谵妄亚型相关的术前神经兴奋/抑制平衡功能障碍，值得进一步开展大规模研究。
