Sleep actigraphic patterns and cognitive status

Abstract

We performed an actigraphic assessment of sleep characteristics in healthy subjects and patients with cognitive impairment. Thirty subjects were included and classified into controls (10 subjects), mild cognitive impairment (10 patients) and mild-to-moderate Alzheimer's disease (10 patients). Sleep quality was assessed using the Pittsburgh Sleep Quality Index. Participants had a 7-day actigraphic record. Sleep parameters collected were time in bed, total sleep time, sleep efficiency, sleep latency, wakefulness after sleep onset, number of awakenings, and mean motor activity. Significant differences between mild cognitive impairment and controls patients were found for sleep latency (p = 0.05); Alzheimer's disease patients had significantly worse scores for Pittsburgh Sleep Quality Index (p = 0.01), time in bed (p = 0.001), total sleep time (p = 0.04), sleep latency, sleep efficiency, motor activity (p = 0.0001) and wakefulness after sleep onset (p = 0.001) compared to controls. When comparing Alzheimer's disease and mild cognitive impairment, differences were significant for sleep latency (p = 0.01), wakefulness after sleep onset (p = 0.004), sleep efficiency, number of awakenings and motor activity (p = 0.0001). In addition to showing a high prevalence of sleep alterations in subjects with cognitive impairment, our data suggest that they are evident from the earliest stages of cognitive decline. Further studies are needed to assess whether early correction of sleep alterations can positively influence the evolution of cognitive impairment. The opportunity to provide clinically meaningful information with a simple assessment of sleep characteristics based on actigraphy suggests that wider use of the approach in patients with cognitive decline should be considered.

Long-term associations between objective sleep quality and quantity and verbal memory performance in normal cognition and mild cognitive impairment

“…Also, a recent meta-analysis of both actigraphy and polysomnography studies, concluded that sleep continuity indices exhibited marginally significant, weak correlations with episodic memory performance, although there was evidence for a stronger moderating effect of WASO duration on the relationship between age and episodic memory performance in older adults as compared to younger individuals ( Hokett et al, 2021 ). Although baseline WASO duration in our sample was higher compared to other actigraphy studies ( Lysen et al, 2020 ; Buratti et al, 2021 ), significant effects of WASO were found only for immediate verbal recall among MCI persons (with additional marginally significant effects on delayed recall in both clinical groups). Methodological issues such as different sample size and study design, demographic characteristics (fewer years of formal schooling of the MCI group), neuropsychological tests and indices used (free recall vs. recognition measures; associative vs. non-associative memory tasks), and the shorted actigraphic period used in the present study may have led to the aforementioned discrepancies.…”

Characteristics of macroscopic sleep structure in patients with mild cognitive impairment: a systematic review

“…The initial search yielded 5,747 articles (PubMed 1,697, Embase 1,368, Web of Science 1,792, Cochrane Library 354, CNKI 153, SinoMed 331, Wanfang Data 30, VIP Data 22), excluding duplicates of the remaining 3,976 articles. After the title and abstract were read, further reading of the full text was performed and an evaluation of literature quality, 25 titles were ultimately included ( 26 – 50 ). The literature screening process can be seen in Figure 1 .…”

“…The 25 papers that were included ( 26 – 50 ) covered nine countries and were published between 2008 and 2021. Hita-Yañez et al published in 2012 ( 31 ) and 2013 ( 32 ) and were in the same study group, so the basic information of both papers was combined.…”

Sleep Duration Positively Correlates with Global Cognition in the Non-Demented Older Adults with High School or above Education

“…The incidence of insomnia is much higher in older adults, due to medical and social factors, as well as comorbid disorders in the elderly [5]. The lack of high-quality nocturnal sleep leads to day-time dysfunction, such as fatigue, tiredness, drowsiness, distress and impairment in social, occupational, behavioral, academic, or other functional domains [2,3,6,7].…”