Inner dialogue dysfunction and the abusive comments of the dominant hemisphere.

Inner dialogue and inner speech are normal systems of cerebral intrapersonal communication, crucial to self-awareness. Lesions affecting the cerebral network involved in these systems have been associated with the occurrence of Auditory Verbal Hallucinations (AVHs). These are regarde as a continuum phenomenon experienced by healthy, individuals, as well as those with psychiatric disorders.

Neuronal viability/astrocyte activity ratio in the dorsolateral prefrontal cortex as a biomarker of Alzheimer's dementia: a proton magnetic resonance spectroscopy study.

N-acetyl-aspartate (NAA) and myo-inositol (mI) are neurometabolites reflecting neuronal viability and astrocyte activity, respectively. These are quantified using proton magnetic resonance spectroscopy (1H-MRS) and may be biomarkers for Alzheimer's disease dementia (AD). Our objectives were: 1) Compare dorsolateral prefrontal cortex (DLPFC) NAA and mI levels between AD and cognitively healthy control participants (HC) 2) assess if NAA/mI ratio can distinguish groups, and 3) explore the relationship between metabolites and cognition.

Homocysteine, neurodegenerative biomarkers, and APOE ε4 in neurodegenerative diseases.

Introduction: Elevated plasma homocysteine (Hcy) is associated with an increased risk of developing neurodegenerative diseases; however, its relationship with the apolipoprotein E (APOE) ε4 allele has not been well characterized.

Methods: Participants clinically diagnosed with Alzheimer's disease or mild cognitive impairment (AD/MCI), frontotemporal dementia, Parkinson's disease, or cerebrovascular disease were stratified by the presence of the APOE ε4 allele. Volumetric magnetic resonance imaging, plasma amyloid/tau/neurodegeneration biomarkers, and cognitive performance were quantified.

Sex Differences in Cortical Thickness and Neuropsychiatric Symptom Burden Based on APOE4 Homozygosity in Alzheimer's Disease.

Sex differences in patterns of cortical thickness and neuropsychiatric symptom (NPS) burden were examined among individuals with Alzheimer's disease (AD) and two copies (homozygote carriers) of the e4 allele of the apolipoprotein gene (APOE). A total of 752 participants with a clinical etiologic diagnosis of AD were selected from the National Alzheimer's Coordinating Center (NACC) database. Bayesian multilevel regression was used to examine both the within- and between-sex differences in gray-matter cortical thickness and total NPS burden associated with APOE homozygosity.

Effect of personality traits, psychological resilience and life adversities on lifetime violence trajectories: A novel classification model in schizophrenia.

The risk of violence is higher in schizophrenia spectrum disorders (SSD) compared to the general population and it is a pressing and understudied issue. Several dispositional and environmental factors have been previously correlated with violence, however, there has been little success in assessing their ability to predict violence patterns across the life span. This study aims to assess violence prediction based on personality traits, psychological resilience, and life-course adversities in a non-forensic population of SSD patients.

Perivascular spaces, plasma GFAP, and speeded executive function in neurodegenerative diseases.

Introduction: We investigated the effect of perivascular spaces (PVS) volume on speeded executive function (sEF), as mediated by white matter hyperintensities (WMH) volume and plasma glial fibrillary acidic protein (GFAP) in neurodegenerative diseases.

Methods: A mediation analysis was performed to assess the relationship between neuroimaging markers and plasma biomarkers on sEF in 333 participants clinically diagnosed with Alzheimer's disease/mild cognitive impairment, frontotemporal dementia, or cerebrovascular disease from the Ontario Neurodegenerative Disease Research Initiative.

Results: PVS was significantly associated with sEF (c = -0.

Neurophysiological and other features of working memory in older adults at risk for dementia.

Unlabelled: Theta-gamma coupling (TGC) is a neurophysiological process that supports working memory. Working memory is associated with other clinical and biological features. The extent to which TGC is associated with these other features and whether it contributes to working memory beyond these features is unknown.

Neuroanatomical correlates of distracted straight driving performance: a driving simulator MRI study across the lifespan.

Background: Driving is the preferred mode of transportation for adults across the healthy age span. However, motor vehicle crashes are among the leading causes of injury and death, especially for older adults, and under distracted driving conditions. Understanding the neuroanatomical basis of driving may inform interventions that minimize crashes.

Cognitive function based on theta-gamma coupling vs. clinical diagnosis in older adults with mild cognitive impairment with or without major depressive disorder.

Whether individuals with mild cognitive impairment (MCI) and a history of major depressive disorder (MDD) are at a higher risk for cognitive decline than those with MCI alone is still not clear. Previous work suggests that a reduction in prefrontal cortical theta phase-gamma amplitude coupling (TGC) is an early marker of cognitive impairment. This study aimed to determine whether using a TGC cutoff is better at separating individuals with MCI or MCI with remitted MDD (MCI+rMDD) on cognitive performance than their clinical diagnosis.

Neuropsychiatric symptoms and brain morphology in patients with mild cognitive impairment, cerebrovascular disease and Parkinson disease: A cross sectional and longitudinal study.

Objectives: Neuropsychiatric symptoms (NPS) increase risk of developing dementia and are linked to various neurodegenerative conditions, including mild cognitive impairment (MCI due to Alzheimer's disease [AD]), cerebrovascular disease (CVD), and Parkinson's disease (PD). We explored the structural neural correlates of NPS cross-sectionally and longitudinally across various neurodegenerative diagnoses.

Methods: The study included individuals with MCI due to AD, (n = 74), CVD (n = 143), and PD (n = 137) at baseline, and at 2-years follow-up (MCI due to AD, n = 37, CVD n = 103, and PD n = 84).

Heterogeneity of Cognition in Older Adults with Remitted Major Depressive Disorder: A Latent Profile Analysis.

Objectives: To identify data-driven cognitive profiles in older adults with remitted major depressive disorder (rMDD) with or without mild cognitive impairment (MCI) and examine how the profiles differ regarding demographic, clinical, and neuroimaging measures.

Design: Secondary cross-sectional analysis using latent profile analysis.

Setting: Multisite clinical trial in Toronto, Canada.

Age-Related Alterations in Gray Matter Microstructure in Older People With Remitted Major Depression at Risk for Dementia.

Background: Major depressive disorder (MDD) in late life is a risk factor for mild cognitive impairment (MCI) and Alzheimer's disease. However, studies of gray matter changes have produced varied estimates of which structures are implicated in MDD and dementia. Changes in gray matter volume and cortical thickness are macrostructural measures for the microstructural processes of free water accumulation and dendritic spine loss.

Interaction of Alzheimer Disease and Traumatic Brain Injury on Cortical Thickness.

Introduction: Traumatic brain injury (TBI) is associated with an accelerated course of dementia, although biological relationships are incompletely understood.

Methods: The study examined 1124 participants, including 343 with Alzheimer disease (AD), 127 with AD with TBI, 266 cognitively normal adults with TBI, and 388 cognitively normal adults without TBI. Cortical thickness was quantified from T1-weighted magnetic resonance imaging data.

Beta to theta power ratio in EEG periodic components as a potential biomarker in mild cognitive impairment and Alzheimer's dementia.

Background: Alzheimer's dementia (AD) is associated with electroencephalography (EEG) abnormalities including in the power ratio of beta to theta frequencies. EEG studies in mild cognitive impairment (MCI) have been less consistent in identifying such abnormalities. One potential reason is not excluding the EEG aperiodic components, which are less associated with cognition than the periodic components.

Perivascular spaces mediate a relationship between diabetes and other cerebral small vessel disease markers in cerebrovascular and neurodegenerative diseases.

Type 2 diabetes mellitus (T2DM) and hypertension are risk factors for cerebral small vessel disease (SVD); however, few studies have characterised their relationships with MRI-visible perivascular spaces (PVS). MRI was used to quantify deep (d) and periventricular (p) white matter hyperintensities (WMH), lacunes, PVS in the white matter (wmPVS) or basal ganglia (bgPVS), and diffusion metrics in white matter. Patients with T2DM had greater wmPVS volume and there were greater wmPVS volumes in patients with T2DM and hypertension together.

White matter hyperintensities and smaller cortical thickness are associated with neuropsychiatric symptoms in neurodegenerative and cerebrovascular diseases.

Background: Neuropsychiatric symptoms (NPS) are a core feature of most neurodegenerative and cerebrovascular diseases. White matter hyperintensities and brain atrophy have been implicated in NPS. We aimed to investigate the relative contribution of white matter hyperintensities and cortical thickness to NPS in participants across neurodegenerative and cerebrovascular diseases.

Rare neurovascular genetic and imaging markers across neurodegenerative diseases.

Introduction: Cerebral small vessel disease (SVD) is common in patients with cognitive impairment and neurodegenerative diseases such as Alzheimer's and Parkinson's. This study investigated the burden of magnetic resonance imaging (MRI)-based markers of SVD in patients with neurodegenerative diseases as a function of rare genetic variant carrier status.

Methods: The Ontario Neurodegenerative Disease Research Initiative study included 520 participants, recruited from 14 tertiary care centers, diagnosed with various neurodegenerative diseases and determined the carrier status of rare non-synonymous variants in five genes (ABCC6, COL4A1/COL4A2, NOTCH3/HTRA1).

Brain-Cognition Associations in Older Patients With Remitted Major Depressive Disorder or Mild Cognitive Impairment: A Multivariate Analysis of Gray and White Matter Integrity.

Background: Almost half of older patients with major depressive disorder (MDD) present with cognitive impairment, and one-third meet diagnostic criteria for mild cognitive impairment (MCI). However, mechanisms linking MDD and MCI remain unclear. We investigated multivariate associations between brain structural alterations and cognition in 3 groups of older patients at risk for dementia, remitted MDD (rMDD), MCI, and rMDD+MCI, as well as cognitively healthy nondepressed control participants.

Lipopolysaccharide, Immune Biomarkers and Cerebral Amyloid-Beta Deposition in Older Adults With Mild Cognitive Impairment & Major Depressive Disorder.

Objective: Inflammatory activation and increased immune response to lipopolysaccharide occur in both depression and cognitive decline and may link these two conditions. We investigated whether lipopolysaccharide (LPS), LPS binding protein (LBP) and peripheral biomarkers of immune response were associated with increased cerebral deposition of amyloid-beta (Abeta) in older adults with mild cognitive impairment (MCI) and remitted major depressive disorder (rMDD).

Design: Cross-sectional analysis.

Cognitive correlates of antisaccade behaviour across multiple neurodegenerative diseases.

Oculomotor tasks generate a potential wealth of behavioural biomarkers for neurodegenerative diseases. Overlap between oculomotor and disease-impaired circuitry reveals the location and severity of disease processes via saccade parameters measured from eye movement tasks such as prosaccade and antisaccade. Existing studies typically examine few saccade parameters in single diseases, using multiple separate neuropsychological test scores to relate oculomotor behaviour to cognition; however, this approach produces inconsistent, ungeneralizable results and fails to consider the cognitive heterogeneity of these diseases.

Cognitive resilience and severe Alzheimer's disease neuropathology.

Cognitive resilience in Alzheimer's disease (AD) can be defined as retention of high cognition despite presence of considerable cerebral AD lesions. We sought to identify factors associated with this phenomenon. Data were obtained from National Alzheimer's Coordinating Centre (NACC) dataset.