Nadia Gosselin

Université de Montréal | UdeM · Department of Psychology

Background Collaborative research with end-users is an effective way to generate meaningful research applications and support greater impact on practice and knowledge exchange. To address these needs, a Citizen Advisory Group (CAG) of nine older adults (ages 64–80, 67% women) was formed to advise scientists on the development of Brain Health PRO (B...

This study aimed to progress the understanding of idiopathic hypersomnia (IH) by assessing the moderating influence of individual characteristics, such as age, sex, and body mass index (BMI) on sleep architecture. In this retrospective study, 76 IH participants (38.1 ± 11.3 years; 40 women) underwent a clinical interview, an in-laboratory polysomno...

Patients with idiopathic hypersomnia frequently report having unrefreshing naps. However, whether they have abnormal sleep architecture during naps that may explain their unrefreshing aspect is unknown. We compared sleep architecture during short daytime naps in patients with idiopathic hypersomnia reporting unrefreshing and refreshing naps. One‐hu...

Sleep slow waves are the hallmark of deeper non-rapid eye movement sleep. It is generally assumed that gray matter properties predict slow-wave density, morphology, and spectral power in healthy adults. Here, we tested the association between gray matter volume (GMV) and slow-wave characteristics in 27 patients with moderate-to-severe traumatic bra...

INTRODUCTION The limbic system is critical for memory function and degenerates early in the Alzheimer's disease continuum. Whether obstructive sleep apnea (OSA) is associated with alterations in the limbic white matter tracts remains understudied. METHODS Polysomnography, neurocognitive assessment, and brain magnetic resonance imaging (MRI) were p...

Introduction Abnormal cortical synchronization during sleep could affect the restorative function of sleep and consequently, increase daytime sleepiness. Slow wave (SW) density and characteristics provide a unique window of how cortical neurons synchronize during non-rapid eye movement (NREM) sleep. Here, we aimed at verifying whether NREM sleep SW...

Background In traumatic brain injury patients (TBI) admitted to the intensive care unit (ICU), agitation can lead to accidental removal of catheters, devices as well as self-extubation and falls. Actigraphy could be a potential tool to continuously monitor agitation. The objectives of this study were to assess the feasibility of monitoring agitati...

Study Objectives Apolipoprotein E ɛ4 (APOE4) is the strongest genetic risk factor for Alzheimer’s disease (AD). In addition, APOE4 carriers may exhibit sleep disturbances, but conflicting results have been reported, such that there is no clear consensus regarding which aspects of sleep are impacted. Our objective was to compare objective sleep arch...

Introduction: Following a traumatic brain injury (TBI), meal preparation may become challenging as it involves multiple cognitive abilities and sub-tasks. To support this population, the Cognitive Orthosis for coOKing (COOK) was developed in partnership with an alternative residential resource for people with severe TBI. However, little is known a...

Background Rapid-eye movement (REM) sleep highly depends on the activity of cholinergic basal forebrain (BF) neurons and is reduced in Alzheimer’s disease. Here, we investigated the associations between the volume of BF nuclei and REM sleep characteristics, and the impact of cognitive status on these links, in late middle-aged and older participant...

Study objectives: Unrefreshing naps are supportive clinical features of idiopathic hypersomnia (IH) and are reported by more than 50% of IH patients. They are, however, not mandatory for the diagnosis, and their pathophysiological nature is not understood. This study aimed at verifying whether IH patients with and without unrefreshing naps constit...

Introduction Obstructive sleep apnea (OSA) is increasingly recognized as a risk factor for cognitive decline, and has been associated with structural brain alterations in regions relevant to memory processes and Alzheimer’s disease. However, it is unclear whether OSA is associated with disrupted functional connectivity (FC) patterns between these r...

During acute hospitalization, many caregivers decide to stay at the care recipient's bedside over the course of several days or months, coping with a stressful situation and a poor sleeping environment. Our objective was to characterize caregiver sleep-wake cycles during care recipient hospital admission and test the association between sleep locat...

Background Obstructive sleep apnea (OSA) is associated with risk of cognitive decline in older adults. Our group previously observed that more severe OSA was associated with lower functional connectivity between the hippocampus and multiple regions of the default‐mode network (DMN) and the limbic system. However, whether these lower functional conn...

Research on the relationship between obstructive sleep apnea and cognitive functioning has yielded conflicting results, particularly in the older population, and moderators of this association have rarely been studied. Here we investigated the cross-sectional association between obstructive sleep apnea and cognitive functioning as well as the moder...

Challenging behaviours significantly impact the lives of people with traumatic brain injury (TBI) and their family caregivers. However, these behaviours are rarely defined from the perspectives of both individuals, a necessary step to developing interventions targeting meaningful goals for individuals and caregivers. This study aimed to (1) explore...

Sleep disturbances are widely prevalent following a traumatic brain injury (TBI) and have the potential to contribute to numerous post-traumatic physiological, psychological, and cognitive difficulties developing chronically, including chronic pain. An important pathophysiological mechanism involved in the recovery of TBI is neuroinflammation, whic...

The basal forebrain cholinergic system (BFCS) degenerates in Alzheimer’s disease (AD) before the onset of dementia. Interestingly, rapid‐eye movement (REM) sleep is highly dependent on cholinergic activity. In AD patients, REM sleep duration is reduced but the underlying brain mechanisms are still unclear. Our objective was to investigate the assoc...

Studies investigating the possible links between obstructive sleep apnea (OSA) and cognitive dysfunction have yet led to heterogenous results. Individual characteristics, such as sex and age, could moderate this association and explain part of this heterogeneity. Here, we characterized the sex‐ and age‐specific association between OSA risk and cogn...

Neuroimaging studies in obstructive sleep apnea (OSA) have found both gray matter atrophy and hypertrophy in medial temporal lobe subregions, the latter probably reflecting edema. Whether and how these changes progress over time when OSA is treated or untreated remains unclear. Here, we investigated gray matter volume changes in medial temporal lob...

Medial temporal structures, namely the hippocampus, the entorhinal cortex and the parahippocampal gyrus, are particularly vulnerable to Alzheimer’s disease and hypoxemia. Here, we tested the associations between obstructive sleep apnea (OSA) severity and medial temporal lobe volumes in 114 participants aged 55–86 years (35 % women). We also investi...

The sleep slow wave (SW) transition between negative and positive phases is thought to mirror synaptic strength and likely depends on brain health. This transition shows significant age-related changes but has not been investigated in pathological aging. The present study aimed at comparing the transition speed and other characteristics of SW betwe...

Résumé Les syndromes d’hypersomnolence d’origine centrale (c.-à-d. narcolepsie de type-1, narcolepsie de type-2 et hypersomnie idiopathique), la dépression ainsi qu’un sous-type du syndrome post-COVID-19 peuvent être confondus lors de l’établissement d’un diagnostic. Ce défi diagnostique s’explique par un symptôme clinique caractéristique retrouvé...

Study Objectives To examine the longitudinal association between probable insomnia status and both subjective and objective memory decline in middle-aged and older adults. Methods 26,363 participants, ≥45 years, completed baseline and follow-up (3 years after baseline) self-reported evaluations of sleep and memory, and neuropsychological testing i...

Study Objectives Traumatic brain injuries (TBI) cause persistent cerebral damage and cognitive deficits. Because sleep may be a critical factor to brain recovery, we characterized the sleep of patients with traumatic brain injury from early hospitalization to years post-injury, and explored the hypothesis that better sleep during hospitalization pr...

Determining the prevalence and characteristics of individuals susceptible to present with obstructive sleep apnea (OSA) is essential for developing targeted and efficient prevention and screening strategies. We included 27,210 participants aged ≥45 years old (50.3% women) from the Canadian Longitudinal Study on Aging. Using the STOP questionnaire c...

Objective To determine how results on the EXACT (EXAmen Cognitif abrégé en Traumatologie), a new test specifically designed to briefly assess global cognitive functioning during the acute phase of traumatic brain injury (TBI), can predict long-term functional outcome compared to length of post-traumatic amnesia (PTA), a well-established predictor....

Background The association between obstructive sleep apnea and cognitive functioning is not yet fully understood and could be influenced by factors such as sex, age and systemic inflammation. We determined the sex- and age-specific association between obstructive sleep apnea risk and cognitive performance, and the influence of systemic inflammation...

Objectives This study aimed to investigate the feasibility of implementing an assistive technology for meal preparation called COOK within a supported community residence for a person with an acquired brain injury. Methods Using a mixed-methods approach, a multiple baseline single-case experimental design and a descriptive qualitative study were c...

Background Recent studies have suggested that obstructive sleep apnea (OSA) could be a modifiable risk factor for dementia. Consequently, efforts have been made to better understand the role of OSA on brain structure integrity, but results between studies are inconsistent. Discrepancies could be partly due to moderating factors (e.g., sex) or compl...

Background Our research team has demonstrated that quantitative electroencephalography (qEEG) slowing during rapid‐eye movement (REM) sleep is a more powerful tool to discriminate patients with mild cognitive impairment (MCI) or Alzheimer Disease (AD) from healthy controls than waking EEG. Cortical activation during REM sleep highly depends on the...

Background Women bear the greatest burden of Alzheimer’s disease (AD), and early (<45y) ovarian hormone deprivation via surgical menopause further increases risk (Rocca et al., 2007). Given that sleep disturbance is implicated in AD progression (Lim et al., 2013), an important area of investigation is determining whether younger women with early su...

Background Growing evidence supports associations between cognitive impairment and obstructive sleep apnea (OSA). Our study aimed at determining the age and sex‐specific, independent relationship between risk of having OSA and cognitive performance, and the influence of systemic inflammation on this relationship. Method Our sample included 25,712...

Sleep slow waves are studied for their role in brain plasticity, homeostatic regulation and their changes during aging. Here, we address the possibility that two types of slow waves co-exist in humans. Thirty young and 29 older adults underwent a night of polysomnographic recordings. Using the Transition frequency, slow waves with a slow transition...

Around 40% of dementia risk is attributable to modifiable risk factors such as physical inactivity, hypertension, diabetes and obesity. Recently, sleep disorders, including obstructive sleep apnea (OSA), have also been considered among these factors. However, despite several epidemiological studies investigating the link between OSA and cognitive d...

Introduction Approximately 50% (between 16–74%) of adults with Parkinson’s disease (PD) show excessive daytime sleepiness. Besides its important role for vision, light conveys a powerful stimulating signal for alertness and cognition. Recent research has demonstrated that the blue part of light spectrum is the most efficient in enhancing vigilance...

Obstructive sleep apnea (OSA) is associated with abnormal cerebral perfusion at wakefulness, but whether these anomalies evolve over time is unknown. Here, we examined longitudinal changes in regional cerebral blood flow (rCBF) distribution in late middle‐aged and older adults with treated or untreated OSA. Twelve controls (64.8 ± 8.0 years) and 23...

Even though sleep modification is a hallmark of the aging process, age-related changes in functional connectivity using functional Magnetic Resonance Imaging (fMRI) during sleep, remain unknown. Here, we combined electroencephalography and fMRI to examine functional connectivity differences between wakefulness and light sleep stages (N1 and N2 stag...

Purpose of Review Obstructive sleep apnea is extremely prevalent in the elderly and may precipitate dementia. We review recent advances on gray and white matter structure in obstructive sleep apnea, the impact of treatment, and potential pathological and neurodegenerative processes underlying brain structural changes. Recent Findings Two opposite...

Sleep slow waves are studied for their role in brain plasticity, homeostatic regulation and their changes during aging. Here, we address the possibility that two types of slow waves co-exist in humans. Thirty young and 29 older adults underwent a night of polysomnographic recordings. Using the Transition frequency, slow waves with a slow transition...

Obstructive sleep apnea (OSA) affects the central nervous system (CNS), and may lead to significant deficits in affected patients. The focus on its CNS effects is warranted given the raise in its prevalence and the increased awareness of its links to dementia and several major psychiatric disorders. This article describes the cognitive deficits and...

Background: Obstructive sleep apnea (OSA) is a risk factor for cognitive decline, but the effect of sex on this association is unknown. This study aims at characterizing the relationship between risk of OSA and cognitive function in older men and women. Method: We included 152 women (73 ± 6 years) and 89 men (75 ± 6 years) matched for education, ag...

Background Sleep and circadian problems are known to be common along the Alzheimer’s disease (AD) spectrum. Previous research correlated an increase in CSF Aβ with poor sleep quality through self‐reported questionnaires in cognitively unimpaired (CU) individuals. Research on AD patients however showed an increase in tau‐PET. Today, there is increas...

Background Sleep disturbances and especially reduction of non‐REM (NREM) sleep are common in aging with accumulating evidence showing it might contribute to cognitive decline as well as increase the risk of developing dementia due to Alzheimer’s disease (AD). Lately, sleep disturbances and AD separately have been linked to increase in systemic infl...

Study Objectives Sleep-wake complaints and difficulties in making new learning are among the most persistent and challenging long-term sequelea following moderate-severe traumatic brain injury (TBI). Yet, it is unclear whether, and to what extent, sleep characteristics during the chronic stage of TBI contribute to sleep-wake and cognitive complaint...

Aging is associated with reduced slow wave (SW) density (number SW/min in non-rapid-eye-movement sleep) and amplitude. It has been proposed that an age-related decrease in SW density may be due to a reduction in EEG amplitude instead of a decline in the capacity to generate SW. Here, we propose a data-driven approach to adapt SW amplitude criteria...

Idiopathic hypersomnia is a poorly defined nosological entity and has important phenotype heterogeneity. Moreover, diagnosing idiopathic hypersomnia is challenging as patients can report significant symptoms but may not meet diagnostic criteria on standard objective tests. Advanced analyses of electroencephalographic (EEG) activity could provide ob...

Sleep spindles are an essential part of non-rapid eye movement sleep, notably involved in sleep consolidation, cognition, learning, and memory. These oscillatory waves depend on an interaction loop between the thalamus and the cortex, which relies on a structural backbone of thalamo-cortical white matter tracts. It is still largely unknown if the b...

Objectives The present study aimed at investigating changes in waking electroencephalography (EEG), most specifically regarding spectral power and functional connectivity, in middle-aged and older adults with OSA. We also explored whether changes in spectral power or functional connectivity are associated with polysomnographic characteristics and/o...

Introduction Slow waves and spindles are essential oscillations occurring during NREM sleep that may be disrupted by moderate to severe traumatic brain injury (TBI). We investigated these oscillations in the acute and chronic trauma stage. Methods Four groups were tested with whole-night polysomnography: hospitalized patients with acute TBI (n=10,...

Objective : The role of the clinical neuropsychologist in tertiary trauma center hospitals is to quickly assess the global cognitive functioning of patients who have sustained a traumatic brain injury (TBI) in order to determine their orientation at the time of discharge. However, the few global cognitive instruments available for this clinical pur...

Background Idiopathic rapid eye movement sleep behavior disorder is associated with increased risk of neurodegeneration, but the temporal evolution of regional perfusion, a marker of cerebral activity, has not been characterized. The objective of the current study was to study longitudinal regional perfusion in patients with idiopathic rapid eye mo...

Objective Primary motor (M1) cortical excitability alterations are involved in the development and maintenance of chronic pain. Less is known about M1-cortical excitability implications in the acute phase of an orthopedic trauma. This study aims to assess acute M1-cortical excitability in patients with an isolated upper limb fracture (IULF) in rela...

Characterizing the effects of obstructive sleep apnea (OSA) on the aging brain could be key in our understanding of neurodegeneration in this population. Our objective was to assess white matter properties in newly diagnosed and untreated adults with mild to severe OSA. Sixty‐five adults aged 55 to 85 were recruited and divided into three groups: c...

Study objectives: Sleep-wake disturbances are frequent among patients hospitalized for traumatic injuries but remain poorly documented because of the lack of tools validated for hospitalized patients. This study aimed to validate actigraphy for nighttime sleep monitoring of hospitalized patients with severe traumatic injuries, using ambulatory pol...

Background Based on associations between sleep spindles, cognition, and sleep-dependent memory processing, here we evaluated potential relationships between levels of CSF Aβ42, P-tau, and T-tau with sleep spindle density and other biophysical properties of sleep spindles in a sample of cognitively normal elderly individuals. Methods One-night in-l...

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Introduction: Recent studies have suggested that obstructive sleep apnea (OSA) is a risk factor for cognitive deficits in cognitively healthy older adults. However, whether this association exists in older adults who present abnormal cognitive decline is unknown. This study aims at characterizing the relationship between risk of OSA and episodic me...

Objectives: Sleep complaints are common during the menopause transition. However, it is difficult to disentangle changes in sleep related to aging from those directly due to menopause. We compared sleep disorders in 45 to 60-year-old women in a large population-based study, according to menopausal status. Methods: Women aged between 45 and 60 ye...

Objective: Primary motor (M1) cortical excitability alterations are involved in the development and maintenance of chronic pain. Less is known about M1-cortical excitability implications in the acute phase of an orthopedic trauma. This study aims to assess acute M1-cortical excitability in patients with an isolated upper limb fracture (IULF) in rel...

Introduction Agitated behaviours (AB) constitute hallmark behaviours of intensive care unit (ICU) patients recovering from traumatic brain injury (TBI). These behaviours create significant challenges for patients and healthcare providers including the need for pharmacologic treatment, delaying mechanical ventilation weaning and mobilization, and co...

Study Objectives In young adults, sleep is associated with important changes in cerebral connectivity during the first cycle of non-rapid eye movement (NREM) sleep. Our study aimed to evaluate how electroencephalography (EEG) connectivity during sleep differs between young and older individuals, and across the sleep cycles. Methods We used imagina...

Study Objectives To test whether the sleep-wake cycle disruption in patients hospitalized with traumatic brain injury (TBI) (1) is also found in patients with traumatic injuries other than TBI (non-TBI) and (2) is associated with a weaker or abnormal circadian clock signal. Methods Forty-two non-mechanically ventilated and non-sedated patients hos...

Objectives: This study seeks to evaluate the incidence rate of heterotopic ossification (HO) formation in patients afflicted by an isolated limb fracture (ILF) and a concomitant mild traumatic brain injury (mTBI). Methods: The current study is an observational study including ILF patients with or without a concomitant mTBI recruited from an orth...

Objectives: This study examined the differences in cognitive function between middle-aged and older adults with insomnia disorder, insomnia symptoms only or no insomnia symptoms, in the context of other health and lifestyle factors. Methods: 28,485 participants >45 years completed questionnaires, physical examinations, and neuropsychological tes...

Study objectives: Recent studies show that obstructive sleep apnea (OSA) is a possible contributor to abnormal cognitive decline in older adults. These new observations create the need to identify older adults with OSA who are at risk of the developing dementia if not treated. This study's goal was to verify whether self-reported cognitive complai...