Sleep spindles and slow oscillations predict cognition and biomarkers of neurodegeneration in mild to moderate Alzheimer's disease

Alzheimer s & Dementia, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Abstract INTRODUCTION Changes in sleep physiology can predate cognitive symptoms by decades persons with Alzheimer's disease (AD), but it remains unclear which characteristics predict and neurodegenerative changes after AD onset. METHODS Using data from a prospective cohort of mild to moderate ( n = 60), we analyzed non‐rapid eye movement spindles slow oscillations (SOs) at baseline their associations amyloid beta (Aβ) tau cognition 3‐year follow‐up. RESULTS Higher spindle SO activity predicted significant Aβ baseline, lower Disease Assessment Scale Cognitive Subscale (better performance) score, higher Mini‐Mental State Examination score 36 months. Spindles SOs mediated the effect phosphorylated 181 (pTau181)/Aβ42 on cognition, while pTau181/aβ42 moderated cognition. DISCUSSION Our findings demonstrate that during constitute predictive non‐invasive biomarkers neurodegeneration patients. Highlights Sleep long‐term performance AD. be predictive, for may one most important modifiable risk factors progression. microarchitecture is novel therapeutic target preserving brain heath. provide targets

Language: Английский

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Perceptions of the use of mobile applications to assess sleep-dependent memory in older adults with subjective and objective cognitive impairment: A focus group approach (Preprint)

JMIR Aging, Journal Year: 2025, Volume and Issue: 8, P. e68147 - e68147

Published: March 19, 2025

Abstract Background Sleep-dependent memory (SDM) is the phenomenon where newly obtained traces are consolidated from short-term stores to long-term memory, underpinning for daily life. Administering SDM tasks presents considerable challenges, particularly older adults with concerns, due need sleep laboratories and research staff being present administer task. In response, we have developed a prototype mobile app aimed at automating data collection process. Objective This study investigates perspectives of adults, subjective or objective cognitive impairment, regarding barriers facilitators using new at-home assessment SDM. Methods total, 11 participants aged 50 years were recruited Healthy Brain Ageing clinic, specialized clinic that focuses on early intervention decline. Two focus groups conducted thematically analyzed NVivo (version 13; Lumivero). Results On average, 68.5 (SD 5.1) years, 4/11 male. Eight had 3 mild (objective) impairment. main themes emerged groups, shedding light participants’ use phones challenges associated transitioning traditional laboratory-based assessments home assessments. These include maintaining accurate data, engaging humans versus robots, ensuring accessibility task compliance. Additionally, potential solutions these identified. Conclusions Our findings underscore importance flexibility in accommodating diverse user needs preferences as well overcoming barriers. While some individuals required high-level assistance, others expressed ability navigate independently minimal support. conclusion, provided valuable insights into modifications, needs, requirements enabling home-based assessment.

Language: Английский

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Threshold Values of Sleep Spindles Features in Healthy Adults Using Scalp‐EEG and Associations With Sleep Parameters

Annals of Clinical and Translational Neurology, Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

ABSTRACT Objective Sleep spindles are an electrophysiological fingerprint of the sleeping human brain. They can be described in terms duration, frequency, amplitude, and density, vary widely according to age sex. Spindles play a role sleep wake functions altered several neurological psychiatric disorders. This study established first threshold values for healthy adults using scalp‐EEG explored their associations with other parameters. Methods observational prospective was conducted 80 participants stratified by sex (40.9 years, range 19–74, 50% females). All underwent in‐laboratory polysomnography. during N2 were analyzed automated procedure categorized as fast (> 13 Hz) or slow (≤ Hz). Results For spindles, duration (0.80–1.11 s), frequency (13.4–14.3 Hz), amplitude (5.2–15.2 μV), density (1.0–5.8 spindles/min). (0.79–1.17 (12.3–12.9 (4.1–13.2 (0.03–3.15 From 40 onwards, both types decreased; amplitudes higher females. Higher associated increased excessive daytime sleepiness proportion slow‐wave sleep. Interpretation provides spindle characteristics adults. The findings emphasize importance investigating develop innovative biomarkers disorders gain deeper insights into functioning

Language: Английский

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Effects of early midlife ovarian removal on sleep: Polysomnography-measured cortical arousal, homeostatic drive, and spindle characteristics

Hormones and Behavior, Journal Year: 2024, Volume and Issue: 165, P. 105619 - 105619

Published: Aug. 22, 2024

Bilateral salpingo-oophorectomy (BSO; removal of ovaries and fallopian tubes) prior to age 48 is associated with elevated risk for both Alzheimer's disease (AD) sleep disorders such as insomnia apnea. In early midlife, individuals BSO show reduced hippocampal volume, function, hippocampal-dependent verbal episodic memory performance changes in sleep. It unknown whether affects fine-grained measurements (sleep microarchitecture) how these might relate memory. We recruited thirty-six midlife participants BSO. Seventeen were taking 17β-estradiol therapy (BSO+ET) 19 had never taken ET (BSO). Twenty age-matched control intact (AMC) also included. Overnight at-home polysomnography recordings collected, along subjective quality hot flash frequency. Multivariate Partial Least Squares (PLS) analysis was used assess varied between groups. Compared AMC, without significantly decreased time spent non-rapid eye movement (NREM) stage 2 well increased NREM 3 beta power, delta spindle power maximum amplitude. Increased amplitude negatively correlated performance. Decreased latency, efficiency, rapid observed BSO+ET. Findings suggest there an association ovarian hormone loss microarchitecture, which may contribute poorer cognitive outcomes be ameliorated by ET.

Language: Английский

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Associations between Quantitative Sleep Analysis and Cognitive Functions in Healthy Adults

Neurological Sciences and Neurophysiology, Journal Year: 2024, Volume and Issue: 41(2), P. 104 - 111

Published: April 1, 2024

A BSTRACT Background: We investigated the role of sleep structure and spindles on cognitive functions in healthy adults. Materials Methods: Our study included 41 participants aged 18–65 years who had no other medical/sleep disorders. All underwent full-night polysomnography (PSG). The Standardized Mini-Mental Examination (SMME), Clock Drawing Test (CDT), forward backward Digit Span (DST), Stroop test, Beck Depression Inventory (BDI) were performed all participants. Results: comprised 12 (29.2%) women 29 (70.8%) men whose mean age was 47.0 ± 12.2 years. DST score significantly better than ( P = 0.025). As increased, number incorrect answers test 0.016) increased. Of PSG data, a shorter duration superficial associated with scores t −2.219; 0.040) −2.463; 0.024). Sleep spindle analysis showed that lower density compared 0.046). trend for negative correlation observed between increased −0.442; 0.051). SMME, CDT, BDI significant associations structure. Decreased correlated higher −0.480; 0.032) −0.489; Conclusion: functioning attention, although they lesser amount women. This finding may be explained by socioenvironmental differences sexes. characteristics, such as duration, are possibly functions.

Language: Английский

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Perceptions of the use of mobile applications to assess memory in older adults with subjective and objective cognitive impairment: A focus group approach (Preprint)

Published: Oct. 29, 2024

Sleep-dependent memory is the phenomenon where newly obtained traces are consolidated from short-term stores to long-term memory, underpinning for daily life. Administering sleep-dependent tasks presents considerable challenges, particularly older adults with concerns due need sleep laboratories and research staff present administer task. In response, we have developed a prototype mobile application aimed at automating data collection process. This study investigates perspectives of adults, both without cognitive impairment, regarding barriers facilitators using new at-home assessment Sleep-Dependent Memory. Eleven participants aged over 50 were recruited Healthy Brain Ageing clinic, specialised clinic that focuses on early intervention decline. Two focus groups conducted thematically analysed NVivo techniques described in Braun Clarke (2006). On average, 68.5 (4/11 male), eight had subjective three mild impairment. main themes emerged groups, shedding light participants' use phones challenges associated transitioning traditional laboratory-based assessments home assessments. These include maintaining accurate data, engaging humans versus robots, ensuring accessibility task compliance. Additionally, potential solutions these identified. Our findings underscore importance app flexibility accommodating diverse user needs preferences, as well overcoming barriers. While some individuals require high-level assistance, others express ability navigate independently minimal support. conclusion, regardless status, desire applications used

Language: Английский

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Screening for obstructive sleep apnea in the memory clinic: A comparison of questionnaires, pulse oximetry, and polysomnography

Journal of Alzheimer s Disease, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 29, 2024

Background Obstructive sleep apnea (OSA) is highly prevalent among older adults and has been associated with cognitive decline dementia risk. The suitability of screening tools for detecting OSA in memory clinic settings unclear. Objective To evaluate the utility validity STOP-Bang questionnaire (SBQ) pulse oximeter as a tool, compared to gold-standard polysomnography (PSG) attending clinic. Methods Participants aged over 50 new onset cognitive/mood concerns attended clinic, then completed SBQ, oximetry, PSG. SBQ oximetry's accuracy moderate-severe severe was evaluated using receiver operating curves. Intraclass correlation Bland-Altman plots oximeter's adjusted oxygen desaturation index (ODI-Ox) PSG's apnea-hypopnea (AHI-PSG). Results Of 194 participants (mean age = 65.6, 64 males) who PSG, 184 138 oximetry. demonstrated limited performance (sensitivity 52%, specificity 62%, AUC 0.600) 18%, 87%, 0.577). Oximetry satisfactory 67%, 73%, 0.769) 50%, 88%, 0.730). diagnostic improved cut-offs at ODI-Ox ≥ 11 AHI-PSG 15 20 30. intraclass indicated acceptable agreement Conclusions findings suggest that while may be unsuitable detect moderate or impairment, oximetry viable tool. Given treatment can optimize slow decline, routine should part assessments.

Language: Английский

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