Publications by authors named "Montplaisir J"

Blood-based biomarkers for Alzheimer's disease (AD) pathology have been intensively investigated as markers for AD-related neurodegeneration. Comorbid AD pathology is common in dementia with Lewy bodies (DLB). Accordingly, we hypothesized that plasma biomarkers associated with AD pathology might be useful to predict DLB in a cohort of idiopathic/isolated REM sleep behavior disorder (iRBD), an incipient synucleinopathy.

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  • The study examined clinical features and conversion rates of isolated rapid-eye movement behavior disorder (iRBD) in a large cohort from Seoul National University Hospital (SNUH) compared to a Montreal cohort.
  • In the SNUH group, fewer patients converted to neurodegenerative diseases, with a lower overall conversion rate and fewer developing dementia with Lewy bodies than in the Montreal cohort.
  • These findings highlight the need for deeper research into factors influencing these disparities, including potential racial and geographical influences.
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Clinical and neuroanatomical correlates of daytime sleepiness in Parkinson's disease (PD) remain inconsistent in the literature. Two studies were conducted here. The first evaluated the interrelation between non-motor and motor symptoms, using a principal component analysis, associated with daytime sleepiness in PD.

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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.

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  • - Sleepwalking diagnosis primarily relies on patients' clinical history, but researchers are exploring polysomnography (PSG) assessments after sleep deprivation to enhance diagnosis.
  • - A study with 124 sleepwalkers found that after 25 hours of sleep deprivation, the number of recorded sleepwalking episodes nearly doubled and the percentage of patients experiencing events increased from 48% to 63%.
  • - The findings suggest that sleep deprivation effectively facilitates the occurrence of sleepwalking events, regardless of age or familial history, indicating its potential as a diagnostic tool in sleep studies.
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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.

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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 performed in 126 individuals aged 55-86 years, including 70 cognitively unimpaired participants and 56 participants with mild cognitive impairment (MCI).

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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 architecture between APOE4 carriers and non-carriers, and to investigate the modulating impact of age, sex, cognitive status, and obstructive sleep apnea (OSA).

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While commonly treated as a uniform state in practice, rapid eye movement sleep contains two distinct microstructures-phasic (presence of rapid eye movement) and tonic (no rapid eye movement). This study aims to identify technical challenges during rapid eye movement sleep microstructure visual classification in patients with rapid eye movement sleep behaviour disorder, and to propose solutions to enhance reliability between scorers. Fifty-seven sleep recordings were randomly allocated into three subsequent batches (n = 10, 13 and 34) for scoring.

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Study Objective: To investigate whether childhood sleep trajectories are associated with mental health symptoms such as social phobia, generalized anxiety, depression, attention deficit hyperactivity disorder (ADHD), conduct problems, and opposition at age 15.

Methods: A total of 2120 children took part in the Quebec Longitudinal Study of Child Development. Childhood sleep trajectories were computed from maternal reports at 2.

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Study Objectives: Idiopathic/isolated rapid eye movement-sleep behavior disorder (iRBD) often precedes the onset of synucleinopathies. Here, we investigated whether baseline resting-state EEG advanced spectral power and functional connectivity differed between iRBD patients who converted towards a synucleinopathy at follow-up and those who did not.

Methods: Eighty-one participants with iRBD (66.

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Background And Objectives: Idiopathic/isolated REM sleep behavior disorder (iRBD) is associated with dementia with Lewy bodies and Parkinson disease. Despite evidence of abnormal cerebral perfusion in iRBD, there is currently no pattern that can predict whether an individual will develop dementia with Lewy bodies or Parkinson disease. The objective was to identify a perfusion signature associated with conversion to dementia with Lewy bodies in iRBD.

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Background And Objectives: Patients with isolated/idiopathic REM sleep behavior disorder (iRBD) are at high risk for developing mild cognitive impairment (MCI) and dementia with Lewy bodies (DLB). However, there is a lack of scientific knowledge regarding the accuracy of cognitive screening tools to identify these conditions in iRBD. This study aimed to determine in iRBD the psychometrics of 2 screening tests to discriminate patients with MCI and those at risk of DLB.

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  • - This study examined how speech and language impairments relate to outcomes in patients with isolated REM sleep behavior disorder (iRBD) across seven different language-speaking centers.
  • - Researchers used advanced speech analysis techniques to identify distinct patterns of language deterioration and followed 180 patients over about 2.7 years, discovering that 26.9% developed neurodegenerative diseases.
  • - Results indicated that greater severity in linguistic and acoustic abnormalities significantly predicted the likelihood of developing conditions like dementia or parkinsonism, suggesting automated language analysis can be a useful predictive tool for identifying patients at risk.
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  • Since 2014, there has been more public awareness about isolated/idiopathic REM sleep behavior disorder (iRBD) in Montreal, aiming to help people recognize symptoms sooner.
  • A study compared two groups of iRBD patients from different time periods (2004-2013 and 2014-2022) and found that patients presenting in the earlier group experienced faster phenoconversion (progression to a more severe form of the disorder).
  • The increase in self-referrals in the later period contributed to a slower rate of phenoconversion, suggesting that heightened awareness leads to earlier diagnosis but longer survival without severe symptoms.
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Objectives Daytime sleepiness in adolescents has negative impacts on physical, cognitive, and emotional health, with direct or indirect consequences on their mental health. This review aims to describe specialized tools assessing daytime sleepiness in adolescents so that mental health professionals can screen for a variety of sleep disorders, from the rarest ones, such as narcolepsy, to the most common ones, such as sleep-wake cycle delay in adolescents. Method Articles were selected in Medline (https://pubmed.

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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 participants.

Methods: Thirty-one cognitively healthy controls (66.

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  • Obstructive sleep apnea (OSA) is linked to cognitive decline and may affect functional connectivity (FC) between brain regions important for memory, particularly in older adults.
  • Ninety-four participants underwent sleep assessments and neuropsychological tests to examine how OSA severity correlates with FC between the default mode network and medial temporal lobe regions, with results controlled for age, sex, and education.
  • The study found that higher OSA severity measured by the apnea-hypopnea index is associated with reduced FC in specific brain areas, but these patterns did not correlate with oxygen desaturation or micro-arousal indices, and differences were noted based on cognitive status (MCI vs. unimpaired).
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  • Isolated/idiopathic rapid eye movement sleep behavior disorder (iRBD) is a key early indicator of dementia with Lewy bodies (DLB) and Parkinson's disease (PD), allowing for the observation of cognitive decline prior to dementia onset.
  • A study with 754 iRBD participants utilized annual neuropsychological assessments to identify cognitive variables predictive of dementia, revealing that attention and executive function were particularly telling.
  • Findings indicate that cognitive decline starts as much as 10 years before the onset of noticeable dementia, with specific declines in attention, executive function, and verbal memory serving as important indicators.
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  • A study investigated the relationship between the human leukocyte antigen (HLA) locus and synucleinopathies, specifically Lewy body dementia (LBD) and isolated REM sleep behavior disorder (iRBD), which are linked to neuroinflammation.
  • It was found that the HLA-DRB1*11:01 allele was significantly associated with iRBD, while several other alleles showed varying associations.
  • The results imply that the HLA locus may have distinct roles depending on the type of synucleinopathy being examined.
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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 constitute two subtypes of IH based on their demographic/clinical characteristics, and sleep architecture.

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  • * The study analyzed over 6,000 NT1 cases and identified new genetic associations (e.g., CD207, NAB1) tied to immune response, particularly involving T cells.
  • * Results suggest that genetic factors in NT1 also relate to other autoimmune diseases, indicating a shared immune mechanism influenced by environmental factors like infections and vaccinations.
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  • NPC1 is a gene that encodes a protein crucial for cholesterol transport in lysosomes, and mutations in this gene can cause Niemann-Pick disease type C, a lysosomal storage disorder.
  • This study investigated the potential link between NPC1 variants and several alpha synucleinopathies, including Parkinson's disease, dementia with Lewy bodies, and rapid eye movement-sleep behavior disorder, using data from multiple cohorts of individuals of European descent.
  • The results showed that neither common nor rare NPC1 variants were associated with these neurodegenerative disorders, indicating that NPC1 mutations likely do not significantly impact the development of alpha synucleinopathies.
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Sleep plays a fundamental role in brain development and resultant functions. The aim was to verify whether nocturnal sleep duration during early childhood has long-term associations with academic achievement at age 10 years. The present study is part of the Quebec Longitudinal Study of Child Development, a representative cohort of infants born in 1997-1998 in the province of Quebec, Canada.

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