Biological brain age and resilience in cognitively unimpaired 70-year-old individuals.

Introduction: This study investigated the associations of brain age gap (BAG)-a biological marker of brain resilience-with life exposures, neuroimaging measures, biological processes, and cognitive function.

Methods: We derived BAG by subtracting predicted brain age from chronological age in 739 septuagenarians without dementia or neurological disorders. Robust linear regression models assessed BAG associations with life exposures, plasma inflammatory and metabolic biomarkers, magnetic resonance imaging, and cerebrospinal fluid biomarkers of neurodegeneration and vascular brain injury, and cognitive performance.

Divergent neurodegenerative patterns: Comparison of [F] fluorodeoxyglucose-PET- and MRI-based Alzheimer's disease subtypes.

[F] fluorodeoxyglucose (FDG)-PET and MRI are key imaging markers for neurodegeneration in Alzheimer's disease. It has been well established that parieto-temporal hypometabolism on FDG-PET is closely associated with medial temporal atrophy on MRI in Alzheimer's disease. Substantial biological heterogeneity, expressed as distinct subtypes of hypometabolism or atrophy patterns, has been previously described in Alzheimer's disease using data-driven and hypothesis-driven methods.

Associations between antidiabetic medications and cerebrospinal fluid biomarkers of Alzheimer's disease.

Background: It has been hypothesized that insulin resistance is pivotal in mediating amyloid and tau dysregulations in Alzheimer's disease (AD).

Objective: To investigate the impact of different antidiabetic agents, their daily dosage intake, and treatment duration on cerebrospinal fluid (CSF) AD biomarkers among patients with type 2 diabetes.

Methods: This cross-sectional study selected patients between 50 and 80 years with diabetes and CSF AD biomarkers screened between 2017 and 2023 in the VALCODIS Cohort.

CSF levels of brain-derived proteins correlate with brain ventricular volume in cognitively healthy 70-year-olds.

Background: The effect of varying brain ventricular volume on the cerebrospinal fluid (CSF) proteome has been discussed as possible confounding factors in comparative protein level analyses. However, the relationship between CSF volume and protein levels remains largely unexplored. Moreover, the few existing studies provide conflicting findings, indicating the need for further research.

MRI markers of idiopathic normal pressure hydrocephalus in a population study with 791 participants: Exploring reference values and associations.

Purpose: Epidemiological studies on idiopathic normal pressure hydrocephalus (iNPH) imaging markers and their normal values are scarce. This population-based study aimed to analyze several morphologic and volumetric iNPH-related imaging markers in a large sample, determining their distribution, diagnostic accuracy, suggested cut-offs, and associations with iNPH symptoms.

Methods: This cross-sectional study included 791 70 year olds, 40 with radiologically probable iNPH (iNPH) and 751 without iNPH features (reference).

Neuroimaging Correlates of 3 Distinct Physical-Cognitive Phenotypes in Cognitively Normal Older Adults: The Gothenburg H70 Cohort Study.

Background And Objectives: Individuals aged 70 and older frequently experience an increased risk of deficits in both physical and cognitive functions. However, the natural progression and interrelationship of these deficits, as well as their neurologic correlates, remain unclear. We aimed to classify the data-driven physical-cognitive phenotypes and then investigate their associations with neuroimaging markers.

Unveiling the hippocampal subfield changes across the Alzheimer's disease continuum: a systematic review of neuroimaging studies.

Studies exploring the hippocampal subfield atrophy in Alzheimer's disease (AD) have shown contradictory results. This review aims to disentangle such heterogeneity by investigating the dynamic changes of hippocampal subfields across the AD continuum. We systematically searched the PubMed and EMBASE databases for case-control studies.

Long-term effects of cholinesterase inhibitors and memantine on cognitive decline, cardiovascular events, and mortality in dementia with Lewy bodies: An up to 10-year follow-up study.

Introduction: We aimed to assess the impact of cholinesterase inhibitors (ChEIs) and memantine on cognition, major adverse cardiovascular events (MACE) and mortality in dementia with Lewy bodies (DLB).

Methods: A total of 1,095 incident DLB patients from the Swedish Registry on cognitive/dementia disorders were included. Using an inverse probability of treatment weighting, the effect of initiating ChEI or memantine within 90 days of DLB diagnosis and nonuse was evaluated on cognitive trajectories and risks of MACE and death.

Exploring Responsiveness to Highly Challenging Balance and Gait Training in Parkinson's Disease.

Background: Exercise potentially improves gait, balance, and habitual physical activity in Parkinson's disease (PD). However, given the heterogeneous nature of the disease, it is likely that people respond differently to exercise interventions. Factors determining responsiveness to exercise interventions remain unclear.

MRI subtypes in Parkinson's disease across diverse populations and clustering approaches.

Parkinson's disease (PD) is clinically heterogeneous, which suggests the existence of subtypes; however, there has been no consensus regarding their characteristics. This study included 633 PD individuals across distinct cohorts: unmedicated de novo PD, medicated PD, mild-moderate PD, and a cohort based on diagnostic work-up in clinical practice. Additionally, 233 controls were included.

Methods for assessment of rey auditory verbal learning test performance in memory clinic patients and healthy adults - at the cross-roads of learning theory and clinical utility.

Knowledge is still lacking regarding the preferred method for evaluation of learning in the Rey Auditory Verbal Learning Test (RAVLT). Validity of different methods was examined by the effect size in differentiating diagnostic stages in memory clinic patients versus healthy adults and the strength of association between RAVLT performance and brain atrophy. The study included individuals with dementia ( = 247), Mild Cognitive Impairment (MCI,  = 709), Subjective Cognitive Impairment (SCI,  = 175) and cognitively unimpaired adults serving as healthy controls (HC,  = 102).

Assessing CT-based Volumetric Analysis via Transfer Learning with MRI and Manual Labels for Idiopathic Normal Pressure Hydrocephalus.

Background: Brain computed tomography (CT) is an accessible and commonly utilized technique for assessing brain structure. In cases of idiopathic normal pressure hydrocephalus (iNPH), the presence of ventriculomegaly is often neuroradiologically evaluated by visual rating and manually measuring each image. Previously, we have developed and tested a deep-learning-model that utilizes transfer learning from magnetic resonance imaging (MRI) for CT-based intracranial tissue segmentation.

Predicting progression from subjective cognitive decline to mild cognitive impairment or dementia based on brain atrophy patterns.

Background: Alzheimer's disease (AD) is a progressive neurodegenerative disorder where pathophysiological changes begin decades before the onset of clinical symptoms. Analysis of brain atrophy patterns using structural MRI and multivariate data analysis are an effective tool in identifying patients with subjective cognitive decline (SCD) at higher risk of progression to AD dementia. Atrophy patterns obtained from models trained to classify advanced AD versus normal subjects, may not be optimal for subjects at an early stage, like SCD.

Nutrition guidance within a multimodal intervention improves diet quality in prodromal Alzheimer's disease: Multimodal Preventive Trial for Alzheimer's Disease (MIND-AD).

Background: Multimodal lifestyle interventions can benefit overall health, including cognition, in populations at-risk for dementia. However, little is known about the effect of lifestyle interventions in patients with prodromal Alzheimer's disease (AD). Even less is known about dietary intake and adherence to dietary recommendations within this population making it difficult to design tailored interventions for them.

Constructing personalized characterizations of structural brain aberrations in patients with dementia using explainable artificial intelligence.

Deep learning approaches for clinical predictions based on magnetic resonance imaging data have shown great promise as a translational technology for diagnosis and prognosis in neurological disorders, but its clinical impact has been limited. This is partially attributed to the opaqueness of deep learning models, causing insufficient understanding of what underlies their decisions. To overcome this, we trained convolutional neural networks on structural brain scans to differentiate dementia patients from healthy controls, and applied layerwise relevance propagation to procure individual-level explanations of the model predictions.

Multi-pathological contributions toward atrophy patterns in the Alzheimer's disease continuum.

Introduction: Heterogeneity in downstream atrophy in Alzheimer's disease (AD) is predominantly investigated in relation to pathological hallmarks (Aβ, tau) and co-pathologies (cerebrovascular burden) independently. However, the proportional contribution of each pathology in determining atrophy pattern remains unclear. We assessed heterogeneity in atrophy using two recently conceptualized dimensions: (typical AD atrophy at the center and deviant atypical atrophy on either extreme including limbic predominant to hippocampal sparing patterns) and (overall neurodegeneration spanning minimal atrophy to diffuse typical AD atrophy) in relation to Aβ, tau, and cerebrovascular burden.

Grey matter networks in women and men with dementia with Lewy bodies.

Sex differences permeate many aspects of dementia with Lewy bodies (DLB), yet sex differences in patterns of neurodegeneration in DLB remain largely unexplored. Here, we test whether grey matter networks differ between sexes in DLB and compare these findings to sex differences in healthy controls. In this cross-sectional study, we analysed clinical and neuroimaging data of patients with DLB and cognitively healthy controls matched for age and sex.

Altered empathy processing in frontotemporal dementia A task-based fMRI study.

A lack of empathy, and particularly its affective components, is a core symptom of behavioural variant frontotemporal dementia (bvFTD). Visual exposure to images of a needle pricking a hand (pain condition) and Q-tips touching a hand (control condition) is an established functional magnetic resonance imaging (fMRI) paradigm used to investigate empathy for pain (EFP; pain condition minus control condition). EFP has been associated with increased blood oxygen level dependent (BOLD) signal in regions known to become atrophic in the early stages in bvFTD, including the anterior insula and the anterior cingulate.

Ketogenic Diet Intervention on Metabolic and Psychiatric Health in Bipolar and Schizophrenia: A Pilot Trial.

The ketogenic diet (KD, also known as metabolic therapy) has been successful in the treatment of obesity, type 2 diabetes, and epilepsy. More recently, this treatment has shown promise in the treatment of psychiatric illness. We conducted a 4-month pilot study to investigate the effects of a KD on individuals with schizophrenia or bipolar disorder with existing metabolic abnormalities.