The association between brain volume, cortical brain infarcts, and physical frailty

Shared genetic architecture and causal relationship between frailty and schizophrenia

The complex relationship between frailty and schizophrenia has yet to be fully understood. This study aims to clarify their relationship by investigating their genetic links. We hypothesize a shared genetic architecture and a bidirectional causal relationship between the two conditions. Utilizing summary genetic data from European genome-wide association studies, we analyzed genetic associations through global and local correlations, shared genomic loci, tissue enrichments, and functional genes. Bidirectional Mendelian Randomization (MR) was employed to infer causality. Our findings show a positive genetic correlation between frailty and schizophrenia (LDSC: rg = 0.117, p = 6.686 × 10-7; HDL: rg = 0.101, p = 5.63 × 10-13) and local correlations in three genomic regions (chr9: 94167203-96671698, p = 2.21 × 10-6; chr11: 112459488-114257728, p = 1.01 × 10-5; and chr18: 77149991-78017158, p = 9.57 × 10-6). We identified 111 genomic loci associated with both conditions and demonstrated that genetic variants for frailty and schizophrenia share tissue enrichments and functional genes in brain. MR analysis suggests that frailty increases the likelihood of schizophrenia (OR: 1.763, 95% CI: 1.259-2.468, p = 0.001) and vice versa (β: 0.012, 95% CI: 0.006-0.018, p < 0.001). Our research supports the presence of a shared genetic basis and bidirectional causality between frailty and schizophrenia. These findings necessitate further investigation in diverse populations to confirm and expand on this genetic understanding.

Neuroimaging Findings in Nondemented Frail Individuals: A Systematic Review

BACKGROUND

Frailty is a chronic condition characterised by the progressive decline of multiple physiological functions. There is a critical need to investigate neuroimaging findings in nondemented frail individuals to better understand the underlying mechanisms and implications of frailty on brain health. This paper is aimed at reviewing neuroimaging studies assessing brain changes in nondemented frail individuals to understand the neuropsychological basis of frailty.

METHODS

A systematic review was conducted on studies focusing on neuroimaging modalities in frailty, including MRI, fMRI, DTI and PET. The review was based on PRISMA instructions and a two-step screening process. The studies evaluating neuroimaging findings of nondemented frail individuals, regardless of publication time or participant age, were included. Data were extracted from the included studies, and the quality of the studies as well as risk of bias was assessed.

RESULTS

Out of 1604 studies screened, 22 eligible studies were included. Out of these, 10 studies had good quality, while others had fair quality according to the Newcastle Ottawa scale (NOS). Of these studies, 18 used Fried criteria or a modified version of it to diagnose frailty, while the Edmonton frailty score (EFS), Rockwood and Mitnitski frailty index and frailty index (FI) were implemented by the remaining studies. The MRI findings indicated significant differences in brain structure between nondemented frail and robust individuals, including an increased number and size of white matter hyperintensities, reduced grey matter volume, higher cerebrospinal fluid (CSF) volume and increased number of cerebral microbleeds (CMBs) in frail participants compared to the robust ones. The studies showed no significant difference between at-risk and robust groups regarding total intracranial volume (TIV). The number of CMBs was associated with prefrailty status and its severity. fMRI studies showed decreased intranetwork mean functional connectivity (FC) in nondemented frail individuals. DTI studies showed lower fractional anisotropy (FA), higher axial diffusivity (AD) and higher radial diffusivity (RD) in the nondemented frail group. The PET scan study showed that mean cortical beta-amyloid level was not associated with FI, but the accumulation of beta-amyloid in the anterior and posterior putamen and precuneus region significantly correlated with frailty and its severity.

CONCLUSION

The study reveals significant differences in brain structures between nondemented frail and robust individuals, including increased white matter hyperintensities and reduced grey matter volume. These differences suggest that vascular changes and brain atrophy in nondemented frail individuals may contribute to cognitive impairment and dementia in the future.

Frailty increases the risk of Alzheimer's disease in non-demented individuals: A longitudinal cohort study

BACKGROUND

Frailty, which is considered a potential modifiable risk factor for dementia, continues to generate debate when it comes to Alzheimer's disease (AD). Furthermore, the underlying pathological mechanisms linking frailty to AD remain uncertain.

OBJECTIVE

We aimed to investigate the relationship between frailty and the risk of AD while elucidating the connections between frailty, AD biomarkers, and cognitive function.

METHODS

Total of 829 non-frail (261 robust, 568 pre-frail) and 94 frail individuals from the Alzheimer's Disease Neuroimaging Initiative database were recruited. Kaplan-Meier analysis and Cox regression assessed AD risk across diverse frail statuses in 923 non-demented individuals. Multiple linear regression, mixed effects models and causal mediation analyses bootstrapped 10,000 iterations were conducted to examined underlying associations.

RESULTS

The frail group had a 67.7% increased risk of AD than non-frail group (HR = 1.677; 95%CI, 1.179-2.385; p = 0.004), a 61.8% increased risk of AD than pre-frail group (HR = 1.618; 95%CI, 1.131-2.316; p = 0.009) and a far higher risk of AD than robust group (HR = 2.011; 95%CI, 1.263-3.202; p = 0.003). Frailty was associated with cognitive decline (global cognition, memory and executive function), whole brain and hippocampus atrophy, and ventricle dilation. Higher frail degree predicted faster cognitive decline, brain atrophy and ventricle dilation. Frailty's association with cognition was partially mediated by volume of whole brain (29.54%-30.17% of total effect), hippocampus (18.21%-24.55% of total effect), and ventricle (baseline, 7.62%-10.87% of total effect; change rate, 13.30%-24.33% of total effect).

CONCLUSIONS

Frailty as a potential risk factor for AD, further mechanisms investigation is warranted; mitigating frailty could potentially contribute to AD prevention.

Frailty Trajectories Preceding Dementia in the US and UK

Importance

An accessible marker of both biological age and dementia risk is crucial to advancing dementia prevention and treatment strategies. Although frailty is a candidate for that role, the nature of the relationship between frailty and dementia is not well understood.

Objective

To clarify the temporal relationship between frailty and incident dementia by investigating frailty trajectories in the years preceding dementia onset.

Design, Setting, and Participants

Participant data came from 4 prospective cohort studies: the English Longitudinal Study of Ageing, the Health and Retirement Study, the Rush Memory and Aging Project, and the National Alzheimer Coordinating Center. Data were collected between 1997 and 2024 and were analyzed from July 2023 to August 2024. The settings were retirement communities, national-level surveys, and a multiclinic-based cohort. Included individuals were 60 years or older and without cognitive impairment at baseline. Included individuals also had data on age, sex, education level, and ethnicity and a frailty index score calculated at baseline.

Exposure

Frailty was the main exposure, with participants' degrees of frailty quantified using retrospectively calculated frailty index scores.

Main Outcomes and Measures

Incident all-cause dementia ascertained through physician-derived diagnoses, self- and informant-report, and estimated classifications based on combinations of cognitive tests.

Results

The participant number before exclusions was 87 737. After exclusions, data from 29 849 participants (mean [SD] age, 71.6 [7.7] years; 18 369 female [62%]; 257 963 person-years of follow-up; 3154 cases of incident dementia) were analyzed. Bayesian generalized linear mixed regression models revealed accelerations in frailty trajectories 4 to 9 years before incident dementia. Overall, frailty was positively associated with dementia risk (adjusted hazard ratios [aHRs] ranged from 1.18; 95% CI, 1.13-1.24 to 1.73; 95% CI, 1.57-1.92). This association held among participants whose time between frailty measurement and incident dementia exceeded the identified acceleration period (aHRs ranged from 1.18; 95% CI, 1.12-1.23 to 1.43; 95% CI, 1.14-1.80).

Conclusions and Relevance

These findings suggest that frailty measurements may be used to identify high-risk population groups for preferential enrolment into clinical trials for dementia prevention and treatment. Frailty itself may represent a useful upstream target for behavioral and societal approaches to dementia prevention.

Association between surgical admissions, cognition, and neurodegeneration in older people: a population-based study from the UK Biobank

BACKGROUND

Previous studies have shown that major surgical and medical hospital admissions are associated with cognitive decline in older people (aged 40-69 years at recruitment), which is concerning for patients and caregivers. We aimed to validate these findings in a large cohort and investigate associations with neurodegeneration using MRI.

METHODS

For this population-based study, we analysed data from the UK Biobank collected from March 13, 2006, to July 16, 2023, linked to the National Health Service Hospital Episode Statistics database, excluding participants with dementia diagnoses. We constructed fully adjusted models that included age, time, sex, Lancet Commission dementia risk factors, stroke, and hospital admissions with a participant random effect. Primary outcomes were hippocampal volume and white matter hyperintensities, both of which are established markers of neurodegeneration, and exploratory analyses investigated the cortical thickness of Desikan-Killiany-Tourville atlas regions. The main cognitive outcomes were reaction time, fluid intelligence, and prospective and numeric memory. Surgeries were calculated cumulatively starting from 8 years before the baseline evaluation.

FINDINGS

Of 502 412 participants in the UK Biobank study, 492 802 participants were eligible for inclusion in this study, of whom 46 706 underwent MRI. Small adverse associations with cognition were found per surgery: reaction time increased by 0·273 ms, fluid intelligence score decreased by 0·057 correct responses, prospective memory (scored as correct at first attempt) decreased (odds ratio 0·96 [95% CI 0·95 to 0·97]), and numeric memory maximum correct matches decreased by 0·025 in fully adjusted models. Surgeries were associated with smaller hippocampal volume (β=-5·76 mm³ [-7·89 to -3·64]) and greater white matter hyperintensities volume (β=100·02 mm³ [66·17 to 133·87]) in fully adjusted models. Surgeries were also associated with neurodegeneration of the insula and superior temporal cortex.

INTERPRETATION

This population-based study corroborates that surgeries are generally safe but cumulatively are associated with cognitive decline and neurodegeneration. Perioperative brain health should be prioritised for older and vulnerable patients, particularly those who have multiple surgical procedures.

FUNDING

The Australian and New Zealand College of Anaesthetists (ANZCA) Foundation and the University of Sydney.

Frailty and brain changes in older adults without cognitive impairment: A scoping review

Little is known about changes in the brain associated with frailty, in particular, which brain areas could be related to frailty in older people without cognitive impairment. This scoping review mapped evidence on functional and/or structural brain changes in frail older adults without cognitive impairment. The methodology proposed by the JBI® was used in this study. The search in PubMed, PubMed PMC, BVS/BIREME, EBSCOHOST, Scopus, Web of Science, Embase, and PROQUEST was conducted up to January 2023. Studies included following the population, concepts, context and the screening and data extraction were performed by two independent reviewers. A total of 9,912 records were identified, 5,676 were duplicates and were excluded. The remaining articles were screened; 31 were read in full and 17 articles were included. The results showed that lesions in white matter hyperintensities, reduced volume of the hippocampus, cerebellum, middle frontal gyrus, low gray matter volume, cortical atrophy, decreased connectivity of the supplementary motor area, presence of amyloid-beta peptide (aβ) in the anterior and posterior putamen and precuneus regions were more frequently observed in frail older adults, compared with non-frail individuals. Studies have suggested that such findings may be of neurodegenerative or cerebrovascular origin. The identification of these brain alterations in frail older adults through neuroimaging studies contributes to our understanding of the underlying mechanisms of frailty. Such findings may have implications for the early detection of frailty and implementation of intervention strategies.

Cerebrospinal fluid proteomic profile of frailty: Results from the PROLIPHYC cohort

Frailty is a clinical state reflecting a decrease in physiological reserve capacities, known to affect numerous biological pathways and is associated with health issues, including neurodegenerative diseases. However, how global protein expression is affected in the central nervous system in frail subject remains underexplored. In this post hoc cross-sectional biomarker analysis, we included 90 adults (52-85 years) suspected of normal pressure hydrocephalus (NPH) and presenting with markers of neurodegenerative diseases. We investigated the human proteomic profile of cerebrospinal fluid associated with frailty defined by an established cumulated frailty index (FI, average = 0.32), not enriched for neurology clinical features. Using a label-free quantitative proteomic approach, we identified and quantified 999 proteins of which 13 were positively associated with frailty. Pathway analysis with the top positively frailty-associated proteins revealed enrichment for proteins related to inflammation and immune response. Among the 60 proteins negatively associated with frailty, functional pathways enriched included neurogenesis, synaptogenesis and neuronal guidance. We constructed a frailty prediction model using ridge regression with 932 standardized proteins. Our results showed that the "proteomic model" could become an equivalent predictor of FI in order to study chronological age. This study represents the first comprehensive exploration of the proteomic profile of frailty within cerebrospinal fluid. It sheds light on the physiopathology of frailty, particularly highlighting processes of neuroinflammation and inhibition of neurogenesis. Our findings unveil a range of biological mechanisms that are dysregulated in frailty, in NPH subjects at risk of neurodegenerative impairment, offering new perspectives on frailty phenotyping and prediction.

Association between physical frailty and cortical structure in middle-aged and elderly people: a Mendelian randomization study

Introduction

Physical weakness is associated with cortical structures, but the exact causes remain to be investigated. Therefore, we utilized Mendelian randomization (MR) analysis to uncover the underlying connection between frailty and cortical structures.

Methods

The Genome-Wide Association Study (GWAS) on frailty pooled data from publicly available sources such as the UK Biobank and included five indicators of frailty: weakness, walking speed, weight loss, physical activity, and exhaustion. GWAS data on cerebral cortical structure were obtained from the ENIGMA consortium, and we assessed the causal relationship between hereditary frailty and cortical surface area (SA) or cortical thickness (TH). Inverse variance weighting (IVW) was used as the primary estimate, and heterogeneity and multidimensionality were monitored by MR-PRESSO to detect outliers. Additionally, MR-Egger, Cochran's Q test, and weighted median were employed.

Results

At the aggregate level, there was no causal relationship between frailty and cortical thickness or surface area. At the regional level, frailty was associated with the thickness of the middle temporal lobe, parahippocampus, rostral middle frontal lobe, lower parietal lobe, anterior cingulate gyrus, upper temporal lobe, lateral orbital frontal cortex, pericardial surface area, rostral middle frontal lobe, upper temporal lobe, rostral anterior cingulate gyrus, lower parietal lobe, and upper parietal lobe. These results were nominally significant, and sensitivity analyses did not detect any multidirectionality or heterogeneity, suggesting that the results of our analyses are reliable.

Discussion

The results of our analyses suggest a potential causal relationship between somatic weakness and multiple regions of cortical structure. However, the specific mechanisms of influence remain to be investigated. Preliminary results from our analysis suggest that the effects of physical frailty on cortical structures are influenced by various factors related to frailty exposure. This relationship has been documented, and it is therefore both feasible and meaningful to build on existing research to explore the clinical significance of the relationship.

Cross-sectional associations between sedentary time with cognitive engagement and brain volume among community-dwelling vulnerable older adults

AIMS

Vulnerable older adults tend to decrease physical activity (PA) and increase sedentary time (ST). Previous research on the associations between ST and brain volume have yielded inconsistent findings, without considering the impact of cognitive engagement (CE) on cognitive function. We aimed to examine the association between ST with CE and brain volume.

METHODS

A structural magnetic resonance imaging survey was conducted among community-dwelling vulnerable older adults. Brain volumetric measurements were obtained using 3T magnetic resonance imaging and pre-processed using FreeSurfer. ST with low or high CE was assessed using a 12-item questionnaire. PA was assessed by the frequency of light and moderate levels of physical exercise according to the Japanese version of the Cardiovascular Health Study criteria. Participants were categorized into a low PA group and a moderate-to-high PA group.

RESULTS

Among 91 participants (83.1 ± 5.2 years old, 61.5% female), 26 were low PA. The overall sample and moderate-to-high PA group did not show significant positive associations with brain volume for ST with high CE. In the low PA group, isotemporal substitution models showed that replacing ST with low CE by ST with high CE was significantly associated with increased brain volume in some areas, including the rostral and caudal anterior cingulate (β = 0.486-0.618, all P < 0.05, adjusted R2  = 0.344-0.663).

CONCLUSIONS

Our findings suggest that replacing ST with low CE by ST with high CE is positively associated with brain volume in vulnerable older adults with low PA. Geriatr Gerontol Int 2024; 24: 82-89.

Neuroimaging features of depression-frailty phenotype in older adults: a pilot study

OBJECTIVE

Frailty and late-life depression (LLD) often coexist and share several structural brain changes. We aimed to study the joint effect LLD and frailty have on brain structure.

DESIGN

Cross-sectional study.

SETTING

Academic Health Center.

PARTICIPANTS

Thirty-one participants (14 LLD+Frail and 17 Never-depressed+Robust).

MEASUREMENT

LLD was diagnosed by a geriatric psychiatrist according to the Diagnostic and Statistical Manual of Mental Disorders 5th edition for single episode or recurrent major depressive disorder without psychotic features. Frailty was assessed using the FRAIL scale (0-5), classifying subjects as robust (0), prefrail (1-2), and frail (3-5). Participants underwent T1-weighted magnetic resonance imaging in which covariance analysis of subcortical volumes and vertex-wise analysis of cortical thickness values were performed to access changes in grey matter. Participants also underwent diffusion tensor imaging in which tract-based spatial statistics was used with voxel-wise statistical analysis on fractional anisotropy and mean diffusion values to assess changes in white matter (WM).

RESULTS

We found a significant difference in mean diffusion values (48,225 voxels; peak voxel: pFWER=0.005, MINI coord. (X,Y,Z) = -26,-11,27) between the LLD-Frail group and comparison group. The corresponding effect size (f=0.808) was large.

CONCLUSION

We showed the LLD+Frailty group is associated with significant microstructural changes within WM tracts compared to Never-depressed+Robust individuals. Our findings indicate the possibility of a heightened neuroinflammatory burden as a potential mechanism underlying the co-occurrence of both conditions and the possibility of a depression-frailty phenotype in older adults.

Correlation between burst suppression and postoperative delirium in elderly patients: a prospective study

OBJECTIVE

To explore the correlation between intraoperative burst suppression (BS) and postoperative delirium (POD) in elderly patients, and provide more ideas for reducing POD in clinical.

METHODS

Ninety patients, aged over 60 years, who underwent lumbar internal fixation surgery in our hospital were selected. General information of patients was obtained and informed consent was signed during preoperative visits. Patients were divided into burst suppression (BS) group and non-burst suppression (NBS) group by intraoperative electroencephalogram monitoring. Intraoperative systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded, and the variation and minimum value were obtained by calculating. Hemoglobin (HGB), C-reactive protein (CRP), system immune inflammatory index (SII) at 24 and 72 h after surgery, the incidence of postoperative adverse reactions, postoperative hospital stay, and total cost were recorded after operation. POD assessment was performed using CAM within 7 days after surgery or until discharge. SPSS25.0 was used for statistical analysis.

RESULTS

Compared with the NBS group, the number of elderly patients with high frailty level in BS group was more (P = 0.048). There is correlation between BS and POD (OR: 4.954, 95%CI 1.034-23.736, P = 0.045), and most of the POD patients in BS group behave as hyperactive type.

CONCLUSION

The occurrence of intraoperative BS is associated with POD, and elderly patients with frailty are more likely to have intraoperative BS. BS can be used as a predictor of POD.

A genome-wide association study of frailty identifies significant genetic correlation with neuropsychiatric, cardiovascular, and inflammation pathways

Frailty is an aging-related clinical phenotype defined as a state in which there is an increase in a person's vulnerability for dependency and/or mortality when exposed to a stressor. While underlying mechanisms leading to the occurrence of frailty are complex, the importance of genetic factors has not been fully investigated. We conducted a large-scale genome-wide association study (GWAS) of frailty, as defined by the five criteria (weight loss, exhaustion, physical activity, walking speed, and grip strength) captured in the Fried Frailty Score (FFS), in 386,565 European descent participants enrolled in the UK Biobank (mean age 57 [SD 8] years, 208,481 [54%] females). We identified 37 independent, novel loci associated with the FFS (p < 5 × 10-8), including seven loci without prior described associations with other traits. The variants associated with FFS were significantly enriched in brain tissues as well as aging-related pathways. Our post-GWAS bioinformatic analyses revealed significant genetic correlations between FFS and cardiovascular-, neurological-, and inflammation-related diseases/traits, and subsequent Mendelian Randomization analyses identified causal associations with chronic pain, obesity, diabetes, education-related traits, joint disorders, and depressive/neurological, metabolic, and respiratory diseases. The GWAS signals were replicated in the Health and Retirement Study (HRS, n = 9,720, mean age 73 [SD 7], 5,582 [57%] females), where the polygenic risk score built from UKB GWAS was significantly associated with the FFS in HRS individuals (OR per SD of the score 1.27, 95% CI 1.22-1.31, p = 1.3 × 10-11). These results provide new insight into the biology of frailty by comprehensively evaluating its genetic architecture.

Cerebral Cortex Activation and Gait Performance between Healthy and Prefrail Older Adults during Cognitive and Walking Tasks

Pre-frailty is a transitional stage between health and frailty. Previous studies have demonstrated that individuals with pre-frailty experience declines in cognitive and gait performances compared with healthy individuals. However, the basic neural mechanism underlying this needs to be clarified. In this cross-sectional study, twenty-one healthy older adults and fifteen with pre-frailty underwent three conditions, including a single cognitive task (SC), single walking task (SW), and dual-task (DT), while cortical hemodynamic reactions were measured using functional near-infrared spectroscopy (fNIRS). The prefrail group (PG) showed a significantly lower activation of the left dorsolateral prefrontal cortex (L-DLPFC) than the healthy group (HG) when performing SC (p < 0.05). The PG showed a significantly lower Timed Up and Go test and step speed than the HG during SW (p < 0.05). The coefficient of variation (CV) of the step length of the PG was significantly higher than that of the HG when performing DT (p < 0.05). No significant correlation in cerebral cortex activation and gait parameters in the HG when performing SW and DT was noted (p > 0.05). Participants of the PG with a higher oxygenated area in the left anterior prefrontal cortex (L-APFC) had a lower step frequency during SW (r = -0.533, p = 0.041), and so did the following indicators of the PG during DT: L-APFC and step speed (r = -0.557, p = 0.031); right anterior prefrontal cortex and step speed (r = -0.610, p = 0.016); left motor cortex and step speed (r = -0.674, p = 0.006); step frequency (r = -0.656, p = 0.008); and step length (r = -0.535, p = 0.040). The negative correlations between the cerebral cortex and gait parameters of the PG indicated a neural compensatory effect of pre-frailty. Therefore, older adults with pre-frailty promote prefrontal activation to compensate for the impaired sensorimotor systems.

Associations of physical frailty with health outcomes and brain structure in 483 033 middle-aged and older adults: a population-based study from the UK Biobank

BACKGROUND

Physical frailty is a state of increased vulnerability to stressors and is associated with serious health issues. However, how frailty affects and is affected by numerous other factors, including mental health and brain structure, remains underexplored. We aimed to investigate the mutual effects of frailty and health using large, multidimensional data.

METHODS

For this population-based study, we used data from the UK Biobank to examine the pattern and direction of association between physical frailty and 325 health-related measures across multiple domains, using linear mixed-effect models and adjusting for numerous confounders. Participants were included if complete data were available for all five indicators of frailty, all covariates, and at least one health measure. We further examined the association between frailty and brain structure and the role of this association in mediating the relationship between frailty and health outcomes.

FINDINGS

483 033 participants aged 38-73 years were included in the study at baseline (between Dec 19, 2006, and Oct 1, 2010); at a median follow-up of 9 years (IQR 8-10), behavioural data were available for 46 501 participants and neuroimaging data for 40 210 participants. The severity of physical frailty was significantly associated with decreased cognitive performance (Cohen's d=0·025-0·162), increased early-life risks (d=0·026-0·111), unhealthy lifestyle (d=0·013-0·394), poor physical fitness (d=0·007-0·668), increased symptoms of poor mental health (d=0·032-0·607), severe environmental pollution (d=0·013-0·064), and adverse biochemical markers (d=0·025-0·198). Some associations were bidirectional, with the strongest effects on mental health measures. The severity of frailty correlated with increased total white matter hyperintensity and lower grey matter volume, particularly in subcortical regions (d=0·027-0·082), which significantly mediated the association between frailty and health-related outcomes, although the mediated effects were small.

INTERPRETATION

Physical frailty is associated with diverse unfavourable health-related outcomes, which can be mediated by differences in brain structure. Our findings offer a framework for guiding preventative strategies targeting both frailty and psychiatric disorders.

FUNDING

National Institute of Mental Health, National Science Foundation.

Resistance Training Increases White Matter Density in Frail Elderly Women

We aimed to investigate the effects of maternal obesity on brain structure and metabolism in frail women, and their reversibility in response to exercise. We recruited 37 frail elderly women (20 offspring of lean/normal-weight mothers (OLM) and 17 offspring of obese/overweight mothers (OOM)) and nine non-frail controls to undergo magnetic resonance and diffusion tensor imaging (DTI), positron emission tomography with Fluorine-18-fluorodeoxyglucose (PET), and cognitive function tests (CERAD). Frail women were studied before and after a 4-month resistance training, and controls were studied once. White matter (WM) density (voxel-based morphometry) was higher in OLM than in OOM subjects. Exercise increased WM density in both OLM and OOM in the cerebellum in superior parietal regions in OLM and in cuneal and precuneal regions in OOM. OLM gained more WM density than OOM in response to intervention. No significant results were found from the Freesurfer analysis, nor from PET or DTI images. Exercise has an impact on brain morphology and cognition in elderly frail women.

Multisystem physiological perspective of human frailty and its modulation by physical activity

"Frailty" is a term used to refer to a state characterized by enhanced vulnerability to, and impaired recovery from, stressors compared with a nonfrail state, which is increasingly viewed as a loss of resilience. With increasing life expectancy and the associated rise in years spent with physical frailty, there is a need to understand the clinical and physiological features of frailty and the factors driving it. We describe the clinical definitions of age-related frailty and their limitations in allowing us to understand the pathogenesis of this prevalent condition. Given that age-related frailty manifests in the form of functional declines such as poor balance, falls, and immobility, as an alternative we view frailty from a physiological viewpoint and describe what is known of the organ-based components of frailty, including adiposity, the brain, and neuromuscular, skeletal muscle, immune, and cardiovascular systems, as individual systems and as components in multisystem dysregulation. By doing so we aim to highlight current understanding of the physiological phenotype of frailty and reveal key knowledge gaps and potential mechanistic drivers of the trajectory to frailty. We also review the studies in humans that have intervened with exercise to reduce frailty. We conclude that more longitudinal and interventional clinical studies are required in older adults. Such observational studies should interrogate the progression from a nonfrail to a frail state, assessing individual elements of frailty to produce a deep physiological phenotype of the syndrome. The findings will identify mechanistic drivers of frailty and allow targeted interventions to diminish frailty progression.

Multivariable Analysis of Pre-operative Brain Atrophy as a Predictor of Long Term Mortality After Carotid Endarterectomy

OBJECTIVE

Brain atrophy is associated with an increased mortality rate in elderly trauma patients and in patients treated with mechanical thrombectomy for acute ischaemic stroke. In the setting of ischaemic stroke, the association between brain atrophy and death is stronger than that of sarcopenia. It has previously been shown that lower masseter area, as a marker of sarcopenia, is linked to lower survival after carotid endarterectomy (CEA). The aim of this study was to investigate whether brain atrophy is also associated with long term mortality in patients undergoing CEA.

METHODS

A cohort of patients treated with CEA between 2004 and 2010 was retrieved from the Tampere University Hospital vascular registry and those with available pre-operative computed tomography (CT) imaging were analysed retrospectively. CT images were evaluated for brain atrophy index (BAI) and masseter muscle surface area and density. The association between BAI and mortality was investigated with Cox regression.

RESULTS

Two hundred and thirty-three patients with a median (interquartile range [IQR]) age of 71 years (64.0, 77.0) were included. Most patients were operated on for symptomatic stenosis (n = 203; 87.1%). The median (IQR) duration of follow up was 115.0 months (66.0, 153.0), and 155 patients (66.5%) died during follow up. BAI was statistically significantly correlated with age (r = .489), average masseter density (r = -.202), and smoking (r = -.186; all p <.005). Increased BAI was statistically significantly associated with overall mortality (hazard ratio [HR] 1.45, 95% confidence interval [CI] 1.25 - 1.68, per one standard deviation [SD] increase) in the univariable analysis, and the association remained (HR 1.23, 95% CI 1.04 - 1.46, per one SD increase) in the multivariable models. Age, peripheral artery disease, and chronic obstructive pulmonary disease were also independently associated with mortality. The optimal cutoff value for BAI was 0.133.

CONCLUSION

Brain atrophy independently predicts the long term post-operative mortality rate after CEA in a cohort containing mainly symptomatic patients. Future studies are needed to validate the results in prospective settings and in asymptomatic patients.

Postoperative delirium is associated with grey matter brain volume loss

Delirium is associated with long-term cognitive dysfunction and with increased brain atrophy. However, it is unclear whether these problems result from or predisposes to delirium. We aimed to investigate preoperative to postoperative brain changes, as well as the role of delirium in these changes over time. We investigated the effects of surgery and postoperative delirium with brain MRIs made before and 3 months after major elective surgery in 299 elderly patients, and an MRI with a 3 months follow-up MRI in 48 non-surgical control participants. To study the effects of surgery and delirium, we compared brain volumes, white matter hyperintensities and brain infarcts between baseline and follow-up MRIs, using multiple regression analyses adjusting for possible confounders. Within the patients group, 37 persons (12%) developed postoperative delirium. Surgical patients showed a greater decrease in grey matter volume than non-surgical control participants [linear regression: B (95% confidence interval) = -0.65% of intracranial volume (-1.01 to -0.29, P < 0.005)]. Within the surgery group, delirium was associated with a greater decrease in grey matter volume [B (95% confidence interval): -0.44% of intracranial volume (-0.82 to -0.06, P = 0.02)]. Furthermore, within the patients, delirium was associated with a non-significantly increased risk of a new postoperative brain infarct [logistic regression: odds ratio (95% confidence interval): 2.8 (0.7-11.1), P = 0.14]. Our study was the first to investigate the association between delirium and preoperative to postoperative brain volume changes, suggesting that delirium is associated with increased progression of grey matter volume loss.

Structural brain signatures of frailty, defined as accumulation of self-reported health deficits in older adults

Background

Frailty in older adults has been associated with reduced brain health. However, structural brain signatures of frailty remain understudied. Our aims were: (1) Explore associations between a frailty index (FI) and brain structure on magnetic resonance imaging (MRI). (2) Identify the most important FI features driving the associations.

Methods

We designed a cross-sectional observational study from a population-based study (The Irish Longitudinal Study on Aging: TILDA). Participants aged ≥50 years who underwent the wave 3 MRI sub-study were included. We measured cortex, basal ganglia, and each of the Desikan-Killiany regional volumes. Age-and sex-adjusted correlations were performed with a 32-item self-reported FI that included conditions commonly tested for frailty in research and clinical settings. A graph theory analysis of the network composed by each FI item and cortex volume was performed. White matter fiber integrity was quantified using diffusion tensor imaging (DTI).

Results

In 523 participants (mean age 69, 49% men), lower cortex and thalamic volumes were independently associated with higher FI. Sensory and functional difficulties, diabetes, polypharmacy, knee pain, and self-reported health were the main FI associations with cortex volume. In the network analysis, cortex volume had a modest influence within the frailty network. Regionally, higher FI was significantly associated with lower volumes in both orbitofrontal and temporal cortices. DTI analyses revealed inverse associations between the FI and the integrity of some association bundles.

Conclusion

The FI used had a recognizable but subtle structural brain signature in this sample. Only some FI deficits were directly associated with cortex volume, suggesting scope for developing FIs that include metrics more specifically related with brain health in future aging neuroscience studies.

Temporal lobe atrophy as a potential predictor of functional outcome in older adults with acute ischemic stroke

BACKGROUND

To explore whether temporal lobe atrophy predicts 3-month functional outcome in a population of patients with anterior circulation acute ischemic stroke (AIS) treated with mechanical thrombectomy (MT).

METHODS

We retrospectively selected patients > 65 years from our prospective endovascular stroke registry between June 2013 and August 2018. According to 3-month modified Rankin Scale (mRS), patients were divided in two groups, named good (mRS ≤ 2) and poor (mRS > 2) outcome. Measures of temporal lobe atrophy (i.e., interuncal distance [IUD], medial temporal lobe thickness [mTLT] and radial width of temporal horn [rWTH]) were assessed on pre-treatment CT scan. Cutoff values for good outcome were obtained for IUD, mTLT and rWTH by means of non-parametric ROC curve analysis. Multivariate analysis was performed to identify predictors of outcome. Ordinal shift analysis based on cutoff values was built to evaluate differences in 3-month mRS.

RESULTS

Among 340 patients, 130 (38.2%) had good and 210 (61.8%) had poor outcome. We found the following cutoff values for good outcome: < 25 mm for IUD, > 15 mm for mTLT and < 4 mm for rWTH. Lower IUD (OR 0.71; 95% CI 0.63-0.80; p < 0.0001) and rWTH (OR 0.73; 95% CI 0.61-0.87; p < 0.0001) and higher mTLT (OR 1.30; 95% CI 1.14-1.49; p < 0.0001) were independently associated with good outcome. Ordinal shift analysis based on cutoff values revealed significant differences in the rate of good outcome for rWTH (49 vs 27%; p < 0.0001), mTLT (52 vs 21%; p < 0.0001) and IUD (57 vs 17%; p < 0.0001).

CONCLUSIONS

Assessment of temporal lobe atrophy may predict functional outcome in patients with AIS treated with MT.

Analysis of the Effects of Ninjin’yoeito on Physical Frailty in Mice

Physical frailty is an aging-related clinical syndrome involving decreases in body weight, mobility, activity, and walking speed that occurs in individuals with sarcopenia and is accelerated by increased oxidative stress. Ninjin’yoeito, a traditional Japanese Kampo medicine, is used for treating conditions, including anemia and physical weakness. Here, we investigated whether ninjin’yoeito could improve physical frailty by controlling oxidative stress in the senescence-accelerated mouse prone 8 (SAMP8) model. First, SAMP8 mice were divided into two groups, ninjin’yoeito treated and untreated, with the former consuming a diet containing 3% ninjin’yoeito from 3 months of age. At 7 months of age, body weight, motor function, locomotor activity, and mean walking speed were measured. Subsequently, mice were euthanized and measured for muscle weight, 8-hydroxy-2′-deoxyguanosine levels in muscle and brain, and cleaved caspase-3 expression in brain. The results showed reductions in weight, locomotor function, locomotion, and average walking speed in the untreated group, which were significantly improved by ninjin’yoeito. Furthermore, 8-hydroxy-2′-deoxyguanosine levels were reduced in muscle and brain from ninjin’yoeito-treated mice, compared with the levels in untreated mice; cleaved caspase-3 expression was similarly reduced in brain from the treated mice, indicating reduced apoptosis. Our findings suggest that ninjin’yoeito inhibits sarcopenia-based physical frailty through its antioxidant effects.

Associations between grip strength, brain structure, and mental health in > 40,000 participants from the UK Biobank

BACKGROUND

Grip strength is a widely used and well-validated measure of overall health that is increasingly understood to index risk for psychiatric illness and neurodegeneration in older adults. However, existing work has not examined how grip strength relates to a comprehensive set of mental health outcomes, which can detect early signs of cognitive decline. Furthermore, whether brain structure mediates associations between grip strength and cognition remains unknown.

METHODS

Based on cross-sectional and longitudinal data from over 40,000 participants in the UK Biobank, this study investigated the behavioral and neural correlates of handgrip strength using a linear mixed effect model and mediation analysis.

RESULTS

In cross-sectional analysis, we found that greater grip strength was associated with better cognitive functioning, higher life satisfaction, greater subjective well-being, and reduced depression and anxiety symptoms while controlling for numerous demographic, anthropometric, and socioeconomic confounders. Further, grip strength of females showed stronger associations with most behavioral outcomes than males. In longitudinal analysis, baseline grip strength was related to cognitive performance at ~9 years follow-up, while the reverse effect was much weaker. Further, baseline neuroticism, health, and financial satisfaction were longitudinally associated with subsequent grip strength. The results revealed widespread associations between stronger grip strength and increased grey matter volume, especially in subcortical regions and temporal cortices. Moreover, grey matter volume of these regions also correlated with better mental health and considerably mediated their relationship with grip strength.

CONCLUSIONS

Overall, using the largest population-scale neuroimaging dataset currently available, our findings provide the most well-powered characterization of interplay between grip strength, mental health, and brain structure, which may facilitate the discovery of possible interventions to mitigate cognitive decline during aging.

Association of the prefrailty with global brain atrophy and white matter lesions among cognitively unimpaired older adults: the Nakajima study

Physical frailty has been associated with adverse outcomes such as dementia. However, the underlying structural brain abnormalities of physical frailty are unclear. We investigated the relationship between physical frailty and structural brain abnormalities in 670 cognitively unimpaired individuals (mean age 70.1 years). Total brain volume (TBV), hippocampal volume (HV), total white matter hypointensities volume (WMHV), and estimated total intracranial volume (eTIV) on the 3D T1-weighted images were automatically computed using FreeSurfer software. Participants were divided into two states of physical frailty (robust vs. prefrail) based on the revised Japanese version of the Cardiovascular Health Study criteria. The multivariable-adjusted mean values of the TBV-to-eTIV ratio was significantly decreased, whereas that of the WMHV-to-eTIV ratio was significantly increased in the prefrail group compared with the robust group. Slowness, one of the components of physical frailty, was significantly associated with reduced TBV-to-eTIV and HV-to-eTIV ratios, and slowness and weakness were significantly associated with an increased WMHV-to-eTIV ratio. Our results suggest that the prefrail state is significantly associated with global brain atrophy and white matter hypointensities. Furthermore, slowness was significantly associated with hippocampal atrophy.

Frailty is associated with cognitive decline independent of cerebral small vessel disease and brain atrophy

Background

To examine the effect of frailty on cognitive decline independent of cerebral small vessel disease (cSVD) and brain atrophy, and whether associations between neuropathology and cognition differed depending on frailty status.

Methods

The Tasmanian Study of Cognition and Gait was a population-based longitudinal cohort study with data collected at 3 phases from 2005 to 2012. Participants aged 60–85 were randomly selected from the electoral roll. Various data were used to operationalize a 36-item frailty index (FI) at baseline. Brain MRI was undertaken to obtain baseline measures of neuropathology. A neuropsychological battery was used to assess cognition at each time point. Generalized linear mixed models were used to examine the effect of frailty and MRI measures on cognition over time. The associations between MRI measures and cognition were explored after stratifying the sample by baseline frailty status. All analyses were adjusted for age, sex, and education.

Results

A total of 385 participants were included at baseline. The mean age was 72.5 years (standard deviation [SD] 7.0), 44% were female (n = 171). In fully adjusted linear mixed models, frailty (FI × time β −0.001, 95% confidence interval [CI] −0.003, −0.001, p = .03) was associated with decline in global cognition, independent of brain atrophy, and cSVD. The association between cSVD and global cognition was significant only in those with low levels of frailty (p = .03).

Conclusion

These findings suggest that frailty is an important factor in early cognitive dysfunction, and measuring frailty may prove useful to help identify future risk of cognitive decline.

Sleep Quality Mediates the Association Between Cerebral Small Vessel Disease Burden and Frailty: A Community-Based Study

Background: Physical frailty is a common problem among older adults which usually leads to adverse health outcomes. The imaging markers of cerebral small vessel disease (CSVD) are associated with frailty, but the underlying mechanisms remain unclear. The present study aimed to investigate the mediating role of sleep quality in the relationship between CSVD burden and frailty. Methods: We performed a cross-sectional study and enrolled community residents. Frailty and sleep quality were measured using the Fried frailty phenotype and the Pittsburgh Sleep Quality Index (PSQI), respectively. A multivariate linear regression analysis and a Bootstrap analysis were performed to examine the association among the key variables and the mediating role of sleep quality. Results: Of the 726 participants (mean age: 65.5 ± 6.5 years, 59.8% female), the numbers (percentages) of the frail, prefrail, and robust residents were 49 (6.7%), 310 (42.7%), and 367 (50.6%), respectively. After adjusting for covariates, the CSVD burden and PSQI score were significantly associated with the frailty score. In addition, sleep quality played a partial mediating role in the association between CSVD burden and physical frailty. The mediating effect was 21.9%. Conclusion: The present study suggests that sleep quality is a mediator of this association between CSVD and frailty in community-dwelling older adults. Improving sleep quality might be helpful to mitigate the risk of frailty in CSVD patients.

Neuropsychiatric systemic lupus erythematosus is associated with a distinct type and shape of cerebral white matter hyperintensities

Objectives

Advanced white matter hyperintensity (WMH) markers on brain MRI may help reveal underlying mechanisms and aid in the diagnosis of different phenotypes of SLE patients experiencing neuropsychiatric (NP) manifestations.

Methods

In this prospective cohort study, we included a clinically well-defined cohort of 155 patients consisting of 38 patients with NPSLE (26 inflammatory and 12 ischaemic phenotype) and 117 non-NPSLE patients. Differences in 3 T MRI WMH markers (volume, type and shape) were compared between patients with NPSLE and non-NPSLE and between patients with inflammatory and ischaemic NPSLE by linear and logistic regression analyses corrected for age, sex and intracranial volume.

Results

Compared with non-NPSLE [92% female; mean age 42 (13) years], patients with NPSLE [87% female; mean age 40 (14) years] showed a higher total WMH volume [B (95%-CI)]: 0.46 (0.0 7 ↔ 0.86); P = 0.021], a higher periventricular/confluent WMH volume [0.46 (0.0 6 ↔ 0.86); P = 0.024], a higher occurrence of periventricular with deep WMH type [0.32 (0.1 3 ↔ 0.77); P = 0.011], a higher number of deep WMH lesions [3.06 (1.2 1 ↔ 4.90); P = 0.001] and a more complex WMH shape [convexity: ‒0.07 (‒0.12 ↔ ‒0.02); P = 0.011, concavity index: 0.05 (0.0 1 ↔ 0.08); P = 0.007]. WMH shape was more complex in inflammatory NPSLE patients [89% female; mean age 39 (15) years] compared with patients with the ischaemic phenotype [83% female; mean age 41 (11) years] [concavity index: 0.08 (0.0 1 ↔ 0.15); P = 0.034].

Conclusion

We demonstrated that patients with NPSLE showed a higher periventricular/confluent WMH volume and more complex shape of WMH compared with non-NPSLE patients. This finding was particularly significant in inflammatory NPLSE patients, suggesting different or more severe underlying pathophysiological abnormalities.

Parkinsonism and cerebrovascular disease

The relationship between cerebrovascular disease and parkinsonism is commonly seen in everyday clinical practice but remains ill-defined and under-recognised with little guidance for the practising neurologist. We attempt to define this association and to illustrate key clinical, radiological and pathological features of the syndrome of Vascular Parkinsonism (VaP). VaP is a major cause of morbidity in the elderly associated with falls, hip fractures and cognitive impairment. Although acute parkinsonism is reported in the context of an acute cerebrovascular event, the vast majority of VaP presents as an insidious syndrome usually in the context of vascular risk factors and radiological evidence of small vessel disease. There may be an anatomic impact on basal ganglia neuronal networks, however the effect of small vessel disease (SVD) on these pathways is not clear. There are now established reporting standards for radiological features of SVD on MRI. White matter hyperintensities and lacunes have been thought to be the representative radiological features of SVD but other features such as the perivascular space are gaining more importance, especially in context of the glymphatic system. It is important to consider VaP in the differential diagnosis of Parkinson disease (PD) and in these situations, neuroimaging may offer diagnostic benefit especially in those patients with atypical presentations or refractoriness to levodopa. Proactive management of vascular risk factors, monitoring of bone density and an exercise program may offer easily attainable therapeutic targets in PD and VaP. Levodopa therapy should be considered in patients with VaP, however the dose and effect may be different from use in PD. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

Psychological and Social Factors Associated with Coexisting Frailty and Cognitive Impairment: A Systematic Review

Those living with coexistent frailty and cognitive impairment are at risk of poorer health outcomes. Research often focuses on identifying biological factors. This review sought to identify the association psychological and social factors have with coexisting physical and cognitive decline. Six databases were systematically searched in July 2020. Studies included individuals aged 60 years or older identified as being both frail and cognitively impaired. A narrative synthesis examined patterns within the data. Nine studies were included, most employed a cross-sectional design. Depression was investigated by all nine studies, those with coexistent frailty and cognitive impairment had higher levels of depressive symptoms than peers. Findings were mixed on social factors, although broadly indicate lower education, living alone and lower material wealth were more frequent in those living with coexistent decline. Further research is needed to explore potentially modifiable psychological and social factors which could lead to the development of supportive interventions.

Associations between brain volumetry and relaxometry signatures and the Edmonton Frail Scale in frailty

Background

Frailty is a geriatric condition characterized by a decreased reserve. The Edmonton frailty scale (EFS) has been widely used as an assessment tool in clinical practice. However, the brain's underlying pathophysiological changes in frailty and their associations with the EFS remain unclear. This study aimed to explore the associations between brain volumetry and relaxometry signatures and the EFS (and each domain score of the EFS) in frailty.

Methods

A total of 40 non-demented subjects were enrolled in this prospective study. Frailty assessment was performed for each subject according to the EFS. All subjects underwent synthetic magnetic resonance imaging (MRI) (MAGnetic resonance image Compilation, MAGiC) and three-dimensional fast spoiled gradient-recalled echo (3D-FSPGR) T1-weighted structural image acquisitions on a 3.0 T MR scanner. Brain segmentation was performed based on quantitative values obtained from the MAGiC and 3D-FSPGR images. Volumetry and relaxometry of the global brain and regional gray matter (GM) were also obtained. The associations between the total EFS score (and the score of each domain) and the brain's volumetry and relaxometry were investigated by partial correlation while eliminating the effects of age. Multiple comparisons of regional GM volumetry and relaxometry analyses were controlled by false discovery rate (FDR) correction. All data were analyzed using the SPSS 13.0 statistical package (IBM, Armonk, NY, USA) and MATLAB (MathWorks, Natick, MA, USA).

Results

For global volumetry, significant correlations were found between multiple global volumetry parameters and the EFS, as well as the cognition score, functional independence score, nutrition score, and functional performance score (P<0.05). For global relaxometry, notable positive correlations were found between the T2 values of gray and white matter (WM) and the EFS (r=0.357, P=0.026; r=0.357, P=0.026, respectively). Significant correlations were also identified between the T2 value of GM, the T1, T2, and PD values of WM, and the cognition score (r=0.426, P=0.007; r=0.456, P=0.003; r=0.377, P=0.018; r=0.424, P=0.007, respectively), functional independence score (r=-0.392, P=0.014; r=-0.611, P<0.001; r=-0.367, P=0.022; r=-0.569, P<0.001, respectively), and functional performance score (r=0.337, P=0.036; r=0.472, P=0.002; r=0.354, P=0.027; r=0.376, P=0.018, respectively). For regional GM volumetry, multiple regions showed significant negative correlations with the EFS (P<0.05). Notable negative correlations were found between multiple regional GM volume and the functional independence score (P<0.05). For regional GM relaxometry, the T1 and T2 values of several regions showed significant negative correlations with the functional independence score (T1 value of caudate, r=-0.617, P<0.001; T2 value of insula, r=-0.510, P=0.015; T2 value of caudate, r=-0.633, P<0.001, respectively). No significant correlation was found between the domain scores of the EFS and regional GM PD values (P>0.05).

Conclusions

In conclusion, brain volumetry and relaxometry signatures showed strong associations with the EFS and some EFS domain scores in frailty. These associations may reveal the possible underlying pathophysiology of the EFS and different domains of the EFS.

Different phenotypes of neuropsychiatric systemic lupus erythematosus are related to a distinct pattern of structural changes on brain MRI

Objectives

The underlying structural brain correlates of neuropsychiatric involvement in systemic lupus erythematosus (NPSLE) remain unclear, thus hindering correct diagnosis.

We compared brain tissue volumes between a clinically well-defined cohort of patients with NPSLE and SLE patients with neuropsychiatric syndromes not attributed to SLE (non-NPSLE). Within the NPSLE patients, we also examined differences between patients with two distinct disease phenotypes: ischemic and inflammatory.

Methods

In this prospective (May 2007 to April 2015) cohort study, we included 38 NPSLE patients (26 inflammatory and 12 ischemic) and 117 non-NPSLE patients. All patients underwent a 3-T brain MRI scan that was used to automatically determine white matter, grey matter, white matter hyperintensities (WMH) and total brain volumes. Group differences in brain tissue volumes were studied with linear regression analyses corrected for age, gender, and total intracranial volume and expressed as B values and 95% confidence intervals.

Results

NPSLE patients showed higher WMH volume compared to non-NPSLE patients (p = 0.004). NPSLE inflammatory patients showed lower total brain (p = 0.014) and white matter volumes (p = 0.020), and higher WMH volume (p = 0.002) compared to non-NPSLE patients. Additionally, NPSLE inflammatory patients showed lower white matter (p = 0.020) and total brain volumes (p = 0.038) compared to NPSLE ischemic patients.

Conclusion

We showed that different phenotypes of NPSLE were related to distinct patterns of underlying structural brain MRI changes. Especially the inflammatory phenotype of NPSLE was associated with the most pronounced brain volume changes, which might facilitate the diagnostic process in SLE patients with neuropsychiatric symptoms.

Key Points

• Neuropsychiatric systemic lupus erythematosus (NPSLE) patients showed a higher WMH volume compared to SLE patients with neuropsychiatric syndromes not attributed to SLE (non-NPSLE).

• NPSLE patients with inflammatory phenotype showed a lower total brain and white matter volume, and a higher volume of white matter hyperintensities, compared to non-NPSLE patients.

• NPSLE patients with inflammatory phenotype showed lower white matter and total brain volumes compared to NPSLE patients with ischemic phenotype.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07970-2.

Functional Connectivity of the Supplementary Motor Network Is Associated with Fried's Modified Frailty Score in Older Adults

Frailty is a geriatric syndrome defined by coexistence of unintentional weight loss, low physical reserve, or activity and is associated with adverse health events. Neuroimaging studies reported structural white matter changes in frail patients. In the current study, we hypothesized that clinical frailty is associated also with functional changes in motion-related cortical areas, that is, (pre-)supplementary motor areas (SMA, pre-SMA). We expected that observed functional changes are related to motor-cognitive test performance. We studied a clinical sample of 143 cognitively healthy patients ≥65 years presenting for elective surgery, enrolled in the BioCog prospective multicentric cohort study on postoperative cognitive disorders. Participants underwent preoperative resting-state functional magnetic resonance imaging, motor-cognitive testing, and assessment of Fried's modified frailty criteria. We analyzed functional connectivity associations with frailty and motor-cognitive test performance. Clinically robust patients (N = 60) showed higher connectivity in the SMA network compared to frail (N = 13) and prefrail (N = 70) patients. No changes were found in the pre-SMA network. SMA connectivity correlated with motor speed (Trail-Making-Test A) and manual dexterity (Grooved Pegboard Test). Our results suggest that diminished functional connectivity of the SMA is an early correlate of functional decline in the older adults . The SMA may serve as a potential treatment target in frailty.

Ongoing Oscillatory Electrophysiological Alterations in Frail Older Adults: A MEG Study

Objective: The role of the central nervous system in the pathophysiology of frailty is controversial. We used magnetoencephalography (MEG) to search for abnormalities in the ongoing oscillatory neural activity of frail individuals without global cognitive impairment.

Methods: Fifty four older (≥70 years) and cognitively healthy (Mini-Mental State Examination ≥24) participants were classified as robust (0 criterion, n = 34) or frail (≥ 3 criteria, n = 20) following Fried's phenotype. Memory, language, attention, and executive function were assessed through well-validated neuropsychological tests. Every participant underwent a resting-state MEG and a T1-weighted magnetic resonance imaging scan. We performed MEG power spectral analyses to compare the electrophysiological profiles of frail and robust individuals. We used an ensemble learner to investigate the ability of MEG spectral power to discriminate frail from robust participants.

Results: We identified increased relative power in the frail group in the mu (p < 0.05) and sensorimotor (p < 0.05) frequencies across right sensorimotor, posterior parietal, and frontal regions. The ensemble learner discriminated frail from robust participants [area under the curve = 0.73 (95% CI = 0.49–0.98)]. Frail individuals performed significantly worse in the Trail Making Test, Digit Span Test (forward), Rey-Osterrieth Complex Figure, and Semantic Fluency Test.

Interpretation: Frail individuals without global cognitive impairment showed ongoing oscillatory alterations within brain regions associated with aspects of motor control, jointly to failures in executive function. Our results suggest that some physical manifestations of frailty might partly arise from failures in central structures relevant to sensorimotor and executive processing.

Preoperative MRI brain phenotypes are related to postoperative delirium in older individuals

The underlying structural correlates of predisposition to postoperative delirium remain largely unknown. A combined analysis of preoperative brain magnetic resonance imaging (MRI) markers could improve our understanding of the pathophysiology of delirium. Therefore, we aimed to identify different MRI brain phenotypes in older patients scheduled for major elective surgery, and to assess the relation between these phenotypes and postoperative delirium. Markers of neurodegenerative and neurovascular brain changes were determined from MRI brain scans in older patients (n = 161, mean age 71, standard deviation 5 years), of whom 24 (15%) developed delirium. A hierarchical cluster analysis was performed. We found six distinct groups of patients with different MRI brain phenotypes. Logistic regression analysis showed a higher odds of developing postoperative delirium in individuals with multi-burden pathology (n = 15 (9%), odds ratio (95% confidence interval): 3.8 (1.1-13.0)). In conclusion, these results indicate that different MRI brain phenotypes are related to a different risk of developing delirium after major elective surgery. MRI brain phenotypes could assist in an improved understanding of the structural correlates of predisposition to postoperative delirium.

Frailty, MRI, and FDG-PET Measures in an Australian Memory Clinic Cohort

Given that the global population is aging, the number of age-related syndromes, such as frailty, is expected to rise in conjunction. Frailty is characterized by the loss of homeostatic reserve, rendering the individual vulnerable to poor health outcomes. Many biological mechanisms have been proposed to contribute to frailty. However, few studies have assessed the associations between frailty and brain diseases or neuroimaging biomarkers. Aims: The aims of this study were to measure the prevalence of frailty in a memory clinic and to examine associations between frailty and brain changes found on magnetic resonance imaging (MRI) and 18-F deoxyglucose (FDG) positron emission tomography (PET) in memory clinic attendees. Methods: A 54-items Frailty Index was retrospectively assessed for all clinic attendees from 2014. Frailty was defined as FI > 0.25. MR images were analyzed for stroke, cerebral small vessel disease [CSVD, including cerebral microbleeds (CMBs), cortical superficial siderosis (CSS), and white matter hyperintensity (WMH)], and neurodegenerative changes [MRI: mesial temporal atrophy (MTA), FDG-PET: regional hypometabolism], blind to clinical findings. Results: There were 209 clinic attendees in 2014, of whom 121 had MRI performed. The prevalence of frailty (using FI) in the memory clinic in 2014 was 38.3% overall (patients without MRI: 43.2%, patients with MRI 34.7%, p = 0.25). Frailty was associated with presence of deep WMH, increased severity of periventricular WMH, and presence of CSS, but not neurodegeneration markers (MTA atrophy/FDG-PET hypometabolism). Conclusion: The findings support the idea that previously reported associations between frailty and imaging evidence of CSVD in other cohorts are also relevant to the Australian clinic setting. Given that a large proportion of memory clinic attendees are frail, there may be opportunities for interventions to reduce preventable adverse health outcomes, such as falls and fractures, and reduce the prevalence and impact of frailty in this cohort.

Preoperative brain MRI features and occurrence of postoperative delirium

OBJECTIVE

Delirium is a frequent complication after surgery with important negative outcomes for affected patients and society. However, it is still largely unknown why some patients have a predisposition for delirium and others not. To increase our understanding of the neural substrate of postoperative delirium, we studied the association between preoperative brain MRI features and the occurrence of delirium after major surgery.

METHODS

A group of 413 patients without dementia (Mean 72 years, SD: 5) was included in a prospective observational two-center study design. The study was conducted at Charité Universitätsmedizin (Berlin, Germany) and the University Medical Center Utrecht (Utrecht, The Netherlands). We measured preoperative brain volumes (total brain, gray matter, white matter), white matter hyperintensity volume and shape, brain infarcts and cerebral perfusion, and used logistic regression analysis adjusted for age, sex, intracranial volume, study center and type of surgery.

RESULTS

Postoperative delirium was present in a total of 70 patients (17%). Preoperative cortical brain infarcts increased the risk of postoperative delirium, although this did not reach statistical significance (OR (95%CI): 1.63 (0.84-3.18). Furthermore, we found a trend for an association of a more complex shape of white matter hyperintensities with occurrence of postoperative delirium (OR (95%CI): 0.97 (0.95-1.00)). Preoperative brain volumes, white matter hyperintensity volume, and cerebral perfusion were not associated with occurrence of postoperative delirium.

CONCLUSION

Our study suggests that patients with preoperative cortical brain infarcts and those with a more complex white matter hyperintensity shape may have a predisposition for developing delirium after major surgery.

Overactive Bladder in Frail Older Adults

Overactive bladder (OAB) and frailty are multidimensional syndromes, and the prevalence of both increases with age. Little evidence exists for a direct association between OAB and frailty, but urinary urgency may well be a precursor of frailty in older people. Frail older adults are no less deserving of treatment than fit older adults, and lifestyle, behavioral, and pharmacological interventions remain the primary options for treatment, with some evidence for efficacy. Data on onabotulinumtoxinA therapy or percutaneous tibial nerve stimulation in frail older adults are sparse. Frail older adults are often excluded from drug trials, but evidence is accumulating that antimuscarinics and, to a lesser extent, beta-adrenergic agonists are safe, well-tolerated, and effective in older adults. Cognitive impairment associated with frailty should not be used as justification for avoiding the use of antimuscarinics. More studies are required to better understand the association between OAB and frailty, as both are associated with poor outcomes and may be amenable to intervention. Drug trials for OAB treatments should be encouraged to include frail older adults, as this population is highly affected yet often excluded.

Cross-Sectional Association Between Cognitive Frailty and White Matter Hyperintensity Among Memory Clinic Patients

BACKGROUND

Cognitive frailty (CF) is defined as simultaneous presence of physical frailty (PF) and cognitive impairment among older adults without dementia. Although white matter hyperintensities (WMH) as expressions of cerebral small vessel disease are associated with physical and cognitive decline and could manifest as CF, this association remains yet to be clarified.

OBJECTS

To clarify the association between CF and WMH among memory clinic patients.

METHODS

The subjects of this cross-sectional study were 121 cognitively normal (CN) and 212 mildly cognitively impaired (MCI) patients who presented to the Memory Clinic at the National Center for Geriatrics and Gerontology of Japan. PF status was defined based on the definition proposed by Fried and colleagues. CF was defined as simultaneous presence of pre-PF or PF and MCI. WMH volumes were measured using an automatic segmentation application. Multiple liner regression analyses with adjustment for cardiovascular risk factors were performed.

RESULTS

Of all subjects, 77 (63.6%) and 22 (18.2%) CN patients and 132 (62.3%) and 65 (30.7%) MCI patients were categorized into pre-PF and PF, respectively. Multiple liner regression analysis showed that those with CF had higher WMH volumes than those without (β= 0.23). When categorized into six groups according to PF and cognitive status, the PF/CN (β= 0.15), pre-PF/MCI (β= 0.41), and PF/MCI (β= 0.34) groups had higher WMH volumes than the non-PF/CN group.

CONCLUSIONS

This study showed increased WMH volumes in CF and PF, indicating that WMH could be one of the key underlying brain pathologies of CF.

Microstructural Neuroimaging of Frailty in Cognitively Normal Older Adults

Physical frailty is an age-related clinical syndrome that is associated with multiple adverse health outcomes, including cognitive impairment and dementia. Recent studies have shown that frailty is associated with specific volumetric neuroimaging characteristics. Whether brain microstructural characteristics, particularly gray matter, associated with frailty exist and what their spatial distribution is have not been explored. We identified 670 participants of the Baltimore Longitudinal Study of Aging who were aged 60 and older and cognitively normal and who had concurrent data on frailty and regional microstructural neuroimaging markers by diffusion tensor imaging (DTI), including mean diffusivity (MD) of gray matter and fractional anisotropy (FA) of white matter. We identified neuroimaging markers that were associated with frailty status (non-frail, pre-frail, frail) and further examined differences between three groups using multivariate linear regression (non-frail = reference). Models were adjusted for age, sex, race, years of education, body mass index, scanner type, and Apolipoprotein E e4 carrier status. Compared to the non-frail participants, those who were frail had higher MD in the medial frontal cortex, several subcortical regions (putamen, caudate, thalamus), anterior cingulate cortex, and a trend of lower FA in the body of the corpus callosum. Those who were pre-frail also had higher MD in the putamen and a trend of lower FA in the body of the corpus callosum. Our study demonstrates for the first time that the microstructure of both gray and white matter differs by frailty status in cognitively normal older adults. Brain areas were not widespread but mostly localized in frontal and subcortical motor areas and the body of the corpus callosum. Whether changes in brain microstructure precede future frailty development warrants further investigation.

Cross-sectional and prospective associations between cerebral cortical thickness and frailty in older adults

BACKGROUND

Several neurodegenerative markers measured by magnetic resonance imaging (MRI) have shown to be related with frailty. While most studies have focused on surrogates of cerebral vascular damage such as increased white matter lesions, the associations between cortical atrophy and frailty were less often investigated.

OBJECTIVES

To investigate the cross-sectional and prospective associations between cortical thickness and frailty evolution in older adults.

METHODS

We enrolled 484 community-dwelling adults aged ≥70 years, participants from the Multidomain Alzheimer Preventive Trial (MAPT), with data on cerebral cortical thickness and frailty. Cortical thickness was acquired by MRI for whole-brain and regional cortices. Two function-specific regions of interest, i.e., mobility-related regions and Alzheimer's disease (AD) signature, were selected on the basis of previous studies. Frailty status was assessed by the Fried frailty phenotype (i.e., weakness, slowness, involuntary weight loss, fatigue and low physical activity level) at baseline, after 6 months and every year until the end of the 5-year follow-up.

RESULTS

Older adults with higher global cortical thickness were less likely to be pre-frail and frail at baseline (adjusted OR: 0.13, 95% CI: 0.03-0.65, p = 0.013). In addition, higher cortical thickness in mobility-related and AD-signature regions were associated with lower likelihood of being pre-frail and frail. Similar associations were observed for having weakness and slowness. However, neither global nor region-specific cortical thickness showed prospective associations with future frailty onset.

CONCLUSIONS

The global and regional cortical thickness cross-sectionally associated with frailty in older adults, but no prospective associations with incident frailty were found. The longitudinal relationship between cortical thickness and frailty evolution requires further investigation.

Brain atrophy predicts mortality after mechanical thrombectomy of proximal anterior circulation occlusion

BACKGROUND

Brain atrophy is associated with an inferior functional outcome in patients undergoing mechanical thrombectomy (MT) for acute ischemic stroke. We hypothesized that brain atrophy determined from pre-interventional non-contrast-enhanced CT scans would also be linked to increased mortality in this cohort.

METHODS

A total of 204 patients treated with MT for acute occlusions of the internal carotid artery (ICA) or the M1 segment of the middle cerebral artery (M1) at Tampere University Hospital, Finland between 2013 and 2017 were retrospectively studied. Brain atrophy index (BAI), masseter muscle surface area and density, chronic ischemic lesions, and white matter lesions were evaluated from pre-interventional CT studies. Logistic regression was applied in analyzing the association of BAI with 3-month mortality.

RESULTS

Median age at baseline was 69.9 years (IQR 15.6) and mortality at 3 months was 13.2% (n=27). BAI, measured with excellent reproducibility (intraclass correlation coefficient ≥0.894, p<0.001), was significantly associated with age (r=0.54), white matter lesions (r=0.43), dental status (r=-0.31), masseter area (r=-0.24), masseter density (r=-0.28), and chronic ischemic lesions (r=0.24) (p≤0.001 for all). In univariable analysis, BAI demonstrated a strong association with mortality (OR 2.02, 95% CI 1.34 to 3.05, per 1 SD increase), and none of the other factors associated with mortality remained as significant when included in the same multivariable model. The results remained similar when extending the follow-up up to 2.5 years.

CONCLUSIONS

Brain atrophy predicts 3-month mortality after MT of the ICA or the M1 independent of age, masseter sarcopenia, chronic ischemic lesions, or white matter lesions.

Multidimensional Approach to Frailty

The concept of frailty syndrome (FS) was first described in the scientific literature three decades ago. For a very long time, we understood it as a geriatric problem, recently becoming one of the dominant concepts in cardiology. It identifies symptoms of FS in one in 10 elderly people. It is estimated that in Europe, 17% of elderly people have FS. The changes in FS resemble and often overlap with changes associated with the physiological aging process of the body. Although there are numerous scientific reports confirming that FS is age correlated, it is not an unavoidable part of the aging process and does not apply only to the elderly. FS is a reversible clinical condition. To maximize benefits of frailty-reversing activities for patient with frailty, identification of its determinants appears to be fundamental. Many of the determinants of the FS have already been known: reduction in physical activity, malnutrition, sarcopenia, polypharmacy, depressive symptom, cognitive disorders, and lack of social support. This review shows that insight into FS determinants is the starting point for building both the comprehensive definition of FS and the adoption of the assessment method of FS, and then successful clinical management.

White Matter Hyperintensities and the Progression of Frailty—The Tasmanian Study of Cognition and Gait

Background

The contribution of cerebral small vessel disease (cSVD) to the pathogenesis of frailty remains uncertain. We aimed to examine the associations between cSVD with progression of frailty in a population-based study of older people.

Methods

People aged between 60 and 85 years were randomly selected form the electoral roll to participate in the Tasmanian Study of Cognition and Gait. Participants underwent self-reported questionnaires, objective gait, cognitive and sensorimotor testing over three phases ranging between 2005 and 2012. These data were used to calculate a 41-item frailty index (FI) at three time points. Baseline brain magnetic resonance imaging was performed on all participants to measure cSVD. Generalized mixed models were used to examine associations between baseline cSVD and progression of frailty, adjusted for confounders of age, sex, level of education, and total intracranial volume.

Results

At baseline (n = 388) mean age was 72 years (SD = 7.0), 44% were female, and the median FI score was 0.20 (interquartile range [IQR] 0.12, 0.27). In fully adjusted models higher burden of baseline white matter hyperintensity (WMH) was associated with frailty progression over 4.4 years (β = 0.03, 95% CI: 0.01, 0.05; p = .004) independent of other SVD markers. Neither baseline infarcts (p = .23), nor microbleeds at baseline (p = .65) were associated with progression of frailty.

Conclusions

We provide evidence for an association between baseline WMHs and progression of frailty. Our findings add to a growing body of literature suggesting WMH is a marker for frailty.

The association between frailty and MRI features of cerebral small vessel disease

Frailty is a common syndrome in older individuals that is associated with poor cognitive outcome. The underlying brain correlates of frailty are unclear. The aim of this study was to investigate the association between frailty and MRI features of cerebral small vessel disease in a group of non-demented older individuals. We included 170 participants who were classified as frail (n = 30), pre-frail (n = 85) or non-frail (n = 55). The association of frailty and white matter hyperintensity volume and shape features, lacunar infarcts and cerebral perfusion was investigated by regression analyses adjusted for age and sex. Frail and pre-frail participants were older, more often female and showed higher white matter hyperintensity volume (0.69 [95%-CI 0.08 to 1.31], p = 0.03 respectively 0.43 [95%-CI: 0.04 to 0.82], p = 0.03) compared to non-frail participants. Frail participants showed a non-significant trend, and pre-frail participants showed a more complex shape of white matter hyperintensities (concavity index: 0.04 [95%-CI: 0.03 to 0.08], p = 0.03; fractal dimensions: 0.07 [95%-CI: 0.00 to 0.15], p = 0.05) compared to non-frail participants. No between group differences were found in gray matter perfusion or in the presence of lacunar infarcts. In conclusion, increased white matter hyperintensity volume and a more complex white matter hyperintensity shape may be structural brain correlates of the frailty phenotype.