Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, University of Salzburg, Salzburg, Austria.
Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Salzburg, Austria.
BMC Med. 2020 May 12;18(1):106. doi: 10.1186/s12916-020-01569-y.
Actigraphy has received increasing attention in classifying rest-activity cycles. However, in patients with disorders of consciousness (DOC), actigraphy data may be considerably confounded by passive movements, such as nursing activities and therapies. Consequently, this study verified whether circadian rhythmicity is (still) visible in actigraphy data from patients with DOC after correcting for passive movements.
Wrist actigraphy was recorded over 7-8 consecutive days in patients with DOC (diagnosed with unresponsive wakefulness syndrome [UWS; n = 19] and [exit] minimally conscious state [MCS/EMCS; n = 11]). The presence and actions of clinical and research staff as well as visitors were indicated using a tablet in the patient's room. Following removal and interpolation of passive movements, non-parametric rank-based tests were computed to identify differences between circadian parameters of uncorrected and corrected actigraphy data.
Uncorrected actigraphy data overestimated the interdaily stability and intradaily variability of patients' activity and underestimated the deviation from a circadian 24-h rhythm. Only 5/30 (17%) patients deviated more than 1 h from 24 h in the uncorrected data, whereas this was the case for 17/30 (57%) patients in the corrected data. When contrasting diagnoses based on the corrected dataset, stronger circadian rhythms and higher activity levels were observed in MCS/EMCS as compared to UWS patients. Day-to-night differences in activity were evident for both patient groups.
Our findings indicate that uncorrected actigraphy data overestimates the circadian rhythmicity of patients' activity, as nursing activities, therapies, and visits by relatives follow a circadian pattern itself. Therefore, we suggest correcting actigraphy data from patients with reduced mobility.
运动活动记录仪在对休息-活动周期进行分类方面受到越来越多的关注。然而，在意识障碍（DOC）患者中，运动活动记录仪数据可能会因被动运动而受到严重干扰，例如护理活动和治疗。因此，本研究在纠正被动运动后，验证了是否仍能在 DOC 患者的运动活动记录仪数据中看到昼夜节律。
对诊断为无反应性觉醒综合征（UWS；n=19）和[退出]最小意识状态/微意识状态（MCS/EMCS；n=11）的 DOC 患者连续 7-8 天记录腕部运动活动记录仪。在患者的房间内使用平板电脑记录临床和研究人员以及访客的出现和活动情况。在去除和插入被动运动后，使用非参数基于等级的检验来识别未经校正和校正的运动活动记录仪数据的昼夜参数之间的差异。
未经校正的运动活动记录仪数据高估了患者活动的日间稳定性和日内可变性，低估了与 24 小时昼夜节律的偏差。未经校正的数据中，只有 5/30（17%）患者的偏差超过 1 小时，而校正后的数据中则有 17/30（57%）患者的偏差超过 1 小时。当根据校正后的数据集对比诊断时，与 UWS 患者相比，MCS/EMCS 患者的昼夜节律更强，活动水平更高。两个患者组的活动都存在昼夜差异。
我们的发现表明，未经校正的运动活动记录仪数据高估了患者活动的昼夜节律性，因为护理活动、治疗和亲属探视本身就遵循昼夜节律模式。因此，我们建议纠正活动能力降低的患者的运动活动记录仪数据。
