Derk-Jan Dijk

Derk-Jan Dijk
University of Surrey · Faculty of Health and Medical Sciences

PhD

About

557
Publications
121,142
Reads
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42,739
Citations
Additional affiliations
November 2009 - February 2010
Woolcock Institute of Medical Research
Position
  • Visiting Scientist
August 1995 - October 1999
Brigham and Women's Hospital
Position
  • Associate Neuroscientist
November 1999 - present
University of Surrey
Position
  • Professor (Full)

Publications

Publications (557)
Preprint
The two-process model (2pm) of sleep regulation is not only a conceptual framework but consists of mathematical equations that have meaning and structure. Despite the apparent simplicity of its graphical representation, the mathematical structure of the 2pm is complex and falls within the wider class of coupled oscillator models. The structure of t...
Article
Full-text available
Background Changes in sleep patterns are common in Alzheimer’s disease and impact the quality of life of both people living with Alzheimer’s (PLWA) and their caregivers. Longitudinal recordings and assessment of night‐to‐night variations in sleep and physiology can improve our understanding of how sleep influences clinical outcomes and caregiver we...
Article
Full-text available
Background Disruption in diurnal rest‐activity rhythms is a hallmark of Alzheimer’s disease. Currently, we know little about how physiology, symptoms, and biomarkers change over the 24‐hour day in people living with Alzheimer’s disease. In particular, we don’t know whether plasma biomarkers of neurodegeneration, which offer promise as diagnostic or...
Preprint
Full-text available
Introduction: Portable electroencephalography (EEG) devices offer the potential for accurate quantification of sleep at home but have not been evaluated in relevant populations. Methods: We assessed the Dreem headband (DHB), and its automated sleep staging algorithm in 62 older adults [Age (mean±SD) 70.5±6.7 years; 12 Alzheimers]. The accuracy of s...
Preprint
Full-text available
Mechanisms regulating human sleep and physiology have evolved in response to rhythmic variation in environmental variables driven by the Earth's rotation around its axis and the sun. To what extent these mechanisms are operable in vulnerable people who are primarily exposed to the indoor environment remains unknown. We analysed 26,523 days of data...
Article
Full-text available
Plasma biomarkers of dementia, including phosphorylated tau (p-tau217), offer promise as tools for diagnosis, stratification for clinical trials, monitoring disease progression, and assessing the success of interventions in those living with Alzheimer’s disease. However, currently, it is unknown whether these dementia biomarker levels vary with the...
Article
Study objectives Alpha and theta oscillations characterize the waking human electroencephalogram (EEG) and can be modulated by closed-loop auditory stimulation (CLAS). These oscillations also occur during rapid eye movement (REM) sleep, but their function here remains elusive. CLAS represents a promising tool to pinpoint how these brain oscillation...
Article
Full-text available
Alpha oscillations play a vital role in managing the brain’s resources, inhibiting neural activity as a function of their phase and amplitude, and are changed in many brain disorders. Developing minimally invasive tools to modulate alpha activity and identifying the parameters that determine its response to exogenous modulators is essential for the...
Preprint
Full-text available
Disturbed sleep is common in ageing and dementia, but objectively quantifying it over time is challenging. We validated a contactless under-mattress pressure sensor and developed a data analysis method to assess sleep patterns in the home over long periods. Data from 13,588 individuals (3.7 million nights) from the general population were compared...
Article
Introduction We investigated whether the relationship between daytime sleepiness and previous night’s sleep duration changes with age using a protocol in which individuals were studied both after habitual sleep duration and after multiple days with extended sleep opportunities. Methods 35 younger (18-32 years old, 18 F) and 18 older (60-76 years o...
Article
Full-text available
Objective: Sleep monitoring has extensively utilized electroencephalogram (EEG) data collected from the scalp, yielding very large data repositories and well-trained analysis models. Yet, this wealth of data is lacking for emerging, less intrusive modalities, such as ear-EEG. Methods and procedures: The current study seeks to harness the abundan...
Article
Full-text available
Accurate assessment of the intrinsic period of the human circadian pacemaker is essential for a quantitative understanding of how our circadian rhythms are synchronized to exposure to natural and man-made light-dark (LD) cycles. The gold standard method for assessing intrinsic period in humans is forced desynchrony (FD) which assumes that the confo...
Article
Full-text available
Twenty-four-hour rhythms in physiology and behaviour are shaped by circadian clocks, environmental rhythms, and feedback of behavioural rhythms onto physiology. In space, 24 h signals such as those associated with the light-dark cycle and changes in posture, are weaker, potentially reducing the robustness of rhythms. Head down tilt (HDT) bed rest i...
Preprint
Full-text available
Background: Alpha and theta oscillations characterize the waking human electroencephalogram (EEG) and can be modulated by closed-loop auditory stimulation (CLAS). These oscillations also occur during rapid eye movement (REM) sleep, but whether they can be modulated by CLAS is not known. Objective: Investigate whether CLAS can modulate alpha and the...
Article
Full-text available
Sleep and circadian rhythm disturbance are predictors of poor physical and mental health, including dementia. Long-term digital technology-enabled monitoring of sleep and circadian rhythms in the community has great potential for early diagnosis, monitoring of disease progression, and assessing the effectiveness of interventions. Before novel digit...
Article
Full-text available
Sleep disturbance is a prevalent and disabling comorbidity in Parkinson’s disease (PD). We performed multi-night (n = 57) at-home intracranial recordings from electrocorticography and subcortical electrodes using sensing-enabled Deep Brain Stimulation (DBS), paired with portable polysomnography in four PD participants and one with cervical dystonia...
Article
Background Increased daytime napping and excessive sleepiness are associated with cognitive decline in older adults, especially in people living with dementia (PLWD) [1]. Subjective assessments of naps are burdensome and maybe unreliable in PLWD and hence there is a need for technologies that provide objective longitudinal assessment of the inciden...
Article
Background Increased daytime napping and excessive sleepiness are associated with cognitive decline in older adults, especially in people living with dementia (PLWD) [1]. Subjective assessments of naps are burdensome and maybe unreliable in PLWD and hence there is a need for technologies that provide objective longitudinal assessment of the inciden...
Article
Background Sleep abnormalities are increasingly recognized as markers and potential drivers of neurodegenerative proteinopathies. However, the sleep phenotype of less common dementias remains poorly characterised. In particular, clinical experience suggests that patients with focal temporal lobe degeneration in the frontotemporal dementia spectrum...
Article
Full-text available
Sleep timing varies between individuals and can be altered in mental and physical health conditions. Sleep and circadian sleep phenotypes, including circadian rhythm sleep-wake disorders, may be driven by endogenous physiological processes, exogeneous environmental light exposure along with social constraints and behavioural factors. Identifying th...
Preprint
Full-text available
Plasma biomarkers of dementia, including phosphorylated tau (p-tau217), offer promise as tools for diagnosis, stratification for clinical trials, monitoring disease progression, and assessing the success of interventions in those living with Alzheimer’s disease. However, currently, it is unknown whether these dementia biomarker levels vary with tim...
Article
Sleep is considered essential for the brain and body. A predominant concept is that sleep is regulated by circadian rhythmicity and sleep homeostasis, processes that were posited to be functionally and mechanistically separate. Here we review and re-evaluate this concept and its assumptions using findings from recent human and rodent studies. Alter...
Article
Full-text available
The regional integrity of brain subcortical structures has been implicated in sleep–wake regulation, however, their associations with sleep parameters remain largely unexplored. Here, we assessed association between quantitative Magnetic Resonance Imaging (qMRI)-derived marker of the myelin content of the brainstem and the variability in the sleep...
Preprint
Full-text available
Sleep and circadian rhythm disturbance are predictors of poor physical and mental health, including dementia. Long-term monitoring of sleep and circadian rhythms in people living in the community may have great potential for early diagnosis, monitoring of disease progression and assessing the effectiveness of interventions in dementia and other hea...
Preprint
Full-text available
Background Sleep disturbance is a prevalent and highly disabling comorbidity in individuals with Parkinson's disease (PD) that leads to worsening of daytime symptoms, reduced quality of life and accelerated disease progression. Objectives We aimed to record naturalistic overnight cortico-basal neural activity in people with PD, in order to determ...
Preprint
Full-text available
Introduction: Longitudinal monitoring of vital signs provides a method for identifying changes to general health in an individual and particularly so in older adults. The nocturnal sleep period provides a convenient opportunity to assess vital signs. Contactless technologies that can be embedded into the bedroom environment are unintrusive and burd...
Preprint
BACKGROUND Longitudinal monitoring of vital signs provides a method for identifying changes to general health in an individual and particularly so in older adults. The nocturnal sleep period provides a convenient opportunity to assess vital signs. Contactless technologies that can be embedded into the bedroom environment are unintrusive and burdenl...
Article
Background Longitudinal monitoring of vital signs provides a method for identifying changes to general health in an individual, particularly in older adults. The nocturnal sleep period provides a convenient opportunity to assess vital signs. Contactless technologies that can be embedded into the bedroom environment are unintrusive and burdenless an...
Article
Full-text available
Background Contactless sleep technologies (CSTs) hold promise for longitudinal, unobtrusive sleep monitoring in the community and at scale. They may be particularly useful in older populations wherein sleep disturbance, which may be indicative of the deterioration of physical and mental health, is highly prevalent. However, few CSTs have been evalu...
Preprint
Full-text available
Transcriptome studies aim at gaining insight into the molecular pathways underlying biological processes. Analyses of gene-expression dynamics in research on circadian rhythms and sleep homeostasis describe these two processes independently, using separate models such as sinusoidal oscillations and exponential saturating functions. Rhythmically exp...
Article
Full-text available
Study objectives: To compare the 24-hour sleep assessment capabilities of two contactless sleep technologies (CSTs) to actigraphy in community-dwelling older adults. Methods: We collected 7 to 14 days of data at home from 35 older adults (age: 65-83), some with medical conditions, using Withings Sleep Analyser (WSA, n=29), Emfit-QS (Emfit, n=17)...
Article
Full-text available
Introduction A variety of dimensions of psychopathology are observed in psychosis. However, the validation of clinical assessment scales, and their latent variable structure, is often derived from cross-sectional rather than longitudinal data, limiting our understanding of how variables interact and reinforce one another. Objectives Using experien...
Preprint
Full-text available
Accurate assessment of the intrinsic period of the human circadian pacemaker is essential for a quantitative understanding of how our circadian rhythms are synchronised to exposure to natural and man-made light-dark cycles. The gold standard method for assessing intrinsic period in humans is forced desynchrony (FD) which assumes that the confoundin...
Preprint
Brain structural integrity has been suggested to contribute to the variability in human sleep quality and composition. The associations between sleep parameters and the regional integrity of subcortical structures implicated in sleep-wake regulation remain, however, largely unexplored. The present study aimed at assessing association between quanti...
Preprint
Background Sleep disturbance is a prevalent and highly disabling comorbidity in individuals with Parkinson’s disease (PD) that leads to worsening of daytime symptoms, accelerated disease progression and reduced quality of life. Objectives We aimed to investigate changes in sleep neurophysiology in PD particularly during non-rapid eye movement (NRE...
Article
Background Disturbances of sleep and night‐time behaviours are amongst the most disabling symptoms of dementia. They often increase carers’ burden and the risk of institutionalization. The causes are complex and are difficult to investigate because of a lack of acceptable methods for monitoring behaviours in the home. Here we show that a passive un...
Article
Background More than 70% of people living with dementia (PLWD) experience sleep disturbances (e.g., early bedtime, long time in bed) even in the early stages of cognitive decline. Light interventions have been proposed as a promising non‐pharmacological approach to improve sleep timing, but current implementations are burdensome and not personalise...
Article
Background Sleep disturbances are both risk factors for and symptoms of dementia. Current methods for assessing sleep disturbances are largely based on either polysomnography (PSG) which is costly and inconvenient, or self‐ or care‐giver reports which are prone to measurement error. Low‐cost methods to monitor sleep disturbances longitudinally and...
Article
Background Sleep disturbance is common among people living with dementia as well as their caregivers. Non‐contact video technology can be used to characterise such disturbances as well as quantifying sleep quality by measuring the number of sleep body positions (poses). Such an approach may be beneficial for home‐based longitudinal clinical monitor...
Preprint
Full-text available
Sleep timing varies between individuals and can be altered in mental and physical health conditions. Sleep and circadian sleep phenotypes, including circadian rhythm sleep-wake disorders, may be driven by endogenous physiological processes, exogeneous environmental light exposure along with social constraints and behavioural factors. Identifying th...
Article
Full-text available
The brain has a unique macroscopic waste clearance system, termed the glymphatic system which utilises perivascular tunnels surrounded by astroglia to promote cerebrospinal-interstitial fluid exchange. Rodent studies have demonstrated a marked increase in glymphatic clearance during sleep which has been linked to a sleep-induced expansion of the ex...
Article
Full-text available
Sleep has been suggested to contribute to myelinogenesis and associated structural changes in the brain. As a principal hallmark of sleep, slow-wave activity (SWA) is homeostatically regulated but also differs between individuals. Besides its homeostatic function, SWA topography is suggested to reflect processes of brain maturation. Here, we assess...
Preprint
BACKGROUND Contactless sleep technologies (CSTs) hold promise for longitudinal, unobtrusive sleep monitoring in health and disease at scale, particularly in older people where the increased incidence of sleep abnormalities with aging is considered a risk factor for several neurodegenerative disorders. However, few CST have been evaluated in older p...
Article
Full-text available
Background: Sleep disorders are common among the aging population and people with neurodegenerative diseases. Sleep disorders have a strong bidirectional relationship with neurodegenerative diseases, where they accelerate and worsen one another. Although one-to-one individual cognitive behavioral interventions (conducted in-person or on the intern...
Article
Full-text available
Survival prediction is integral to oncology and palliative care, yet robust prognostic models remain elusive. We assessed the feasibility of combining actigraphy, sleep diary data, and routine clinical parameters to prognosticate. Fifty adult outpatients with advanced cancer and estimated prognosis of <1 year were recruited. Patients were required...
Article
Background: People living with dementia (PLWD) often exhibit marked sleep disturbances. These cause substantial care challenges and may be causally related to dementia progression. Collecting ecologically valid data on sleep disturbance in naturalistic settings has been difficult. As a result, sleep assessments in PLWD are generally limited to sho...
Article
Background: Disturbances of sleep and night-time behaviours are amongst the most disabling symptoms of dementia. They often increase carers' burden and the risk of institutionalization. The causes are complex and are difficult to investigate because of a lack of acceptable methods for monitoring behaviours in the home. Here we show that a passive...
Article
People living with dementia (PLWD) often exhibit marked sleep disturbances. These cause substantial care challenges and may be causally related to dementia progression. Collecting ecologically valid data on sleep disturbance in naturalistic settings has been difficult. As a result, sleep assessments in PLWD are generally limited to short studies in...
Article
The incidence of sleep disturbances increases with normal aging and is highly prevalent among people living with dementia (PLWD). To facilitate management and improvement of sleep quality in PLWD, validated unintrusive contactless technologies for long term objective monitoring of sleep are needed. Here we evaluate the ability of a contactless slee...
Preprint
Full-text available
The waking brain's ubiquitous alpha oscillations are thought to play an important role in managing the brain's resources, inhibiting neural activity as a function of their phase and amplitude. In accordance with this physiological excitability, perceptual and cognitive processes fluctuate with alpha oscillations. Here we demonstrate that the alpha...
Preprint
Full-text available
Contactless sleep technologies hold promise for longitudinal, unobtrusive sleep monitoring in health and disease at scale, but few have been evaluated in older people. The performance of three contactless sleep technologies (a bedside radar [Somnofy] and two under-mattress devices [Withings sleep analyser and Emfit-QS]) were compared to polysomnogr...
Article
Circadian clocks drive cyclic variations in many aspects of physiology, but some daily variations are evoked by periodic changes in the environment or sleep-wake state and associated behaviors, such as changes in posture, light levels, fasting or eating, rest or activity and social interactions; thus, it is often important to quantify the relative...
Article
Introduction Disturbances of sleep/wake behaviour are amongst the most disabling symptoms of dementia, leading to increased carers’ burden and institutionalisation. The lack of unobtrusive, low- burden technologies validated to monitor sleep in patients living with dementia (PLWD) has prevented longitudinal studies of nocturnal disturbances and the...
Article
The daily alternation between sleep and wakefulness is one of the most dominant features of our lives and is a manifestation of the intrinsic 24 h rhythmicity underlying almost every aspect of our physiology. Circadian rhythms are generated by networks of molecular oscillators in the brain and peripheral tissues that interact with environmental and...
Article
Full-text available
Laboratory-based sleep manipulations show asymmetries between positive and negative affect, but say little about how more specific moods might change. We report extensive analyzes of items from the Positive and Negative Affect Scale (PANAS) during days following nights of chronic sleep restriction (6 h sleep opportunity), during 40 h of acute sleep...
Article
Full-text available
Cortisol is a robust circadian signal that synchronises peripheral circadian clocks with the central clock in the suprachiasmatic nucleus via glucocorticoid receptors that regulate peripheral gene expression. Misalignment of the cortisol rhythm with the sleep–wake cycle, as occurs in shift work, is associated with negative health outcomes, but unde...
Conference Paper
Full-text available
Wearable heart rate monitors offer a cost-effective way of non-invasive, long-term monitoring of cardiac health. Validation of wearable technologies in an older populations is essential for evaluating their effectiveness during deployment in healthcare settings. To this end, we evaluated the validity of heart rate measures from a wearable device, E...
Article
Full-text available
Introduction: Sleep disturbances are commonly reported in people living with Alzheimer's disease (AD), but it is currently unknown whether night-to-night variation in sleep predicts day-to-day variation in vigilance, cognition, mood, and behavior (daytime measures). Methods: Subjective and objective sleep and daytime measures were collected dail...
Article
Full-text available
Several cellular pathways contribute to neurodegenerative tauopathy-related disorders. Microglial activation, a major component of neuroinflammation, is an early pathologic hallmark that correlates with cognitive decline, while the unfolded protein response (UPR) contributes to synaptic pathology. Sleep disturbances are prevalent in tauopathies and...
Article
Full-text available
Background Twenty-four-hour rhythmicity in mammalian tissues and organs is driven by local circadian oscillators, systemic factors, the central circadian pacemaker and light-dark cycles. At the physiological level, the neural and endocrine systems synchronise gene expression in peripheral tissues and organs to the 24-h-day cycle, and disruption of...
Poster
Full-text available
Biological rhythms pervade physiology and pathophysiology across multiple timescales. Insight into the influence of these rhythms on the efficacy of bioelectronic medicine has so far been infeasible due to technology limitations. New devices capable of long-term data recording are highlighting the role of these rhythms during disease. Future device...
Article
Full-text available
Biological rhythms pervade physiology and pathophysiology across multiple timescales. Due to the limited sensing and algorithm capabilities of neuromodulation device technology to-date, insight into the influence of these rhythms on the efficacy of bioelectronic medicine has been infeasible. As the development of new devices begin to mitigate previ...
Article
Full-text available
Background: Nocturnal disturbance is frequently observed in dementia and is a major contributor to institutionalisation. Unobtrusive technology that can quantify sleep/wake and determine bed occupancy during the major nocturnal sleep episode may be beneficial for long-term clinical monitoring and the carer. Such technologies have, however, not been...