Sleep Characteristics and Cognition in Cerebral Amyloid Angiopathy: An Actigraphy-Based Study

This study investigated whether actigraphy-measured sleep characteristics are associated with cognition in patients with sporadic and Dutch-type hereditary cerebral amyloid angiopathy (CAA). CAA is characterized by amyloid-β deposition, increasing the risk of intracerebral hemorrhage and cognitive decline. As sleep is thought to support amyloid clearance, disruptions may exacerbate cognitive decline. We hypothesized that CAA patients would show disrupted sleep and cognitive impairments, with poorer sleep quality relating to worse cognitive performance. Data came from two prospective cohorts at Leiden University Medical Center. Forty-eight participants (mean age = 62 years, 29% female) completed 14 nights of actigraphy and annual neuropsychological testing over five years. Sleep metrics (Total Sleep Time, Wake After Sleep Onset, awakenings, efficiency, fragmentation) were compared with normative values, while cognition (global, memory, speed, executive) was analyzed cross-sectionally...Show moreThis study investigated whether actigraphy-measured sleep characteristics are associated with cognition in patients with sporadic and Dutch-type hereditary cerebral amyloid angiopathy (CAA). CAA is characterized by amyloid-β deposition, increasing the risk of intracerebral hemorrhage and cognitive decline. As sleep is thought to support amyloid clearance, disruptions may exacerbate cognitive decline. We hypothesized that CAA patients would show disrupted sleep and cognitive impairments, with poorer sleep quality relating to worse cognitive performance. Data came from two prospective cohorts at Leiden University Medical Center. Forty-eight participants (mean age = 62 years, 29% female) completed 14 nights of actigraphy and annual neuropsychological testing over five years. Sleep metrics (Total Sleep Time, Wake After Sleep Onset, awakenings, efficiency, fragmentation) were compared with normative values, while cognition (global, memory, speed, executive) was analyzed cross-sectionally and longitudinally. Sleep-cognition associations were examined using correlations and regressions with multiple-testing correction. Compared to normative data, patients slept longer (median TST = 7.2 h vs. 6.3, p < .001) and showed higher sleep efficiency (86% vs. 78%, p < .001), but also more WASO (1.2 h vs. 0.9, p < .001) and more frequent awakenings (14.7 vs. 1.4, p < .001). Cognitive performance was largely preserved at baseline, with only a small proportion showing impairment (executive 14.6%, global 8.9%, memory 8.0%, speed 7.0%). Longitudinally, global cognition, speed, and executive function remained stable; memory showed a modest decline (β = -0.107 per year, p = .005), but this did not survive correction. No significant associations between sleep and cognition were observed cross-sectionally after adjustment. These findings suggest that in CAA, sleep is characterized by fragmentation and increased nocturnal wakefulness, rather than reduced duration. Cognition was largely preserved with subtle vulnerabilities in memory and executive function. The absence of sleep-cognition associations at baseline may reflect preserved cognition, measurement limitations, and restricted sample size. Clinically, “poor sleep” in CAA may reflect altered sleep architecture rather than reduced sleep time. Scientifically, these results highlight the importance of focusing on qualitative sleep characteristics, particularly fragmentation and slow-wave activity, when studying sleep, vascular pathology, and cognition.Show less

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Sleep Characteristics and Cognition in Cerebral Amyloid Angiopathy: An Actigraphy-Based Study