From the reward network to whole-brain metrics: structural connectivity in adolescents and young adults according to body mass index and genetic risk of obesity

BACKGROUND

Obesity is a multifactorial condition. Genetic variants, such as the fat mass and obesity related gene (FTO) polymorphism, may increase the vulnerability of developing obesity by disrupting dopamine signaling within the reward network. Yet, the association of obesity, genetic risk of obesity, and structural connectivity of the reward network in adolescents and young adults remains unexplored. We investigate, in adolescents and young adults, the structural connectivity differences in the reward network and at the whole-brain level according to body mass index (BMI) and the FTO rs9939609 polymorphism.

METHODS

One hundred thirty-two adolescents and young adults (age range: [10, 21] years, BMI z-score range: [-1.76, 2.69]) were included. Genetic risk of obesity was determined by the presence of the FTO A allele. Whole-brain and reward network structural connectivity were analyzed using graph metrics. Hierarchical linear regression was applied to test the association between BMI-z, genetic risk of obesity, and structural connectivity.

RESULTS

Higher BMI-z was associated with higher (B = 0.76, 95% CI = [0.30, 1.21], P = 0.0015) and lower (B = -0.003, 95% CI = [-0.006, -0.00005], P = 0.048) connectivity strength for fractional anisotropy at the whole-brain level and of the reward network, respectively. The FTO polymorphism was not associated with structural connectivity nor with BMI-z.

CONCLUSIONS

We provide evidence that, in healthy adolescents and young adults, higher BMI-z is associated with higher connectivity at the whole-brain level and lower connectivity of the reward network. We did not find the FTO polymorphism to correlate with structural connectivity. Future longitudinal studies with larger sample sizes are needed to assess how genetic determinants of obesity change brain structural connectivity and behavior.

Sleep quality in individuals with post-COVID-19 condition: Relation with emotional, cognitive and functional variables

The study aimed to assess sleep quality in PCC patients and its predictors by analysing its relationship with emotional, cognitive and functional variables, as well as possible differences based on COVID-19 severity. We included 368 individuals with PCC and 123 healthy controls (HCs) from the NAUTILUS Project (NCT05307549 and NCT05307575). We assessed sleep quality (Pittsburgh Sleep Quality Index, PSQI), anxiety (Generalized Anxiety Disorder, GAD-7), depression (Patient Health Questionnaire, PHQ-9), global cognition (Montreal Cognitive Assessment, MoCA), everyday memory failures (Memory Failures of Everyday Questionnaire, MFE-30), fatigue (Chadler Fatigue Questionnaire, CFQ), quality of life (European Quality of Life-5 Dimensions, EQ-5D), and physical activity levels (International Physical Activity Questionnaire, IPAQ). 203 were nonhospitalized, 83 were hospitalized and 82 were admitted to the intensive care unit (ICU). We found statistically significant differences in the PSQI total score between the PCC and HC groups (p < 0.0001), but there were no differences among the PCC groups. In the multiple linear regressions, the PHQ-9 score was a predictor of poor sleep quality for mild PCC patients (p = 0.003); GAD-7 (p = 0.032) and EQ-5D (p = 0.011) scores were predictors of poor sleep quality in the hospitalized PCC group; and GAD-7 (p = 0.045) and IPAQ (p = 0.005) scores were predictors of poor sleep quality in the group of ICU-PCC. These results indicate that worse sleep quality is related to higher levels of depression and anxiety, worse quality of life and less physical activity. Therapeutic strategies should focus on these factors to have a positive impact on the quality of sleep.

Cognitive and emotional predictors of quality of life and functioning after COVID-19

OBJECTIVE

A long-term decline in health-related quality of life (HRQoL) has been reported after coronavirus disease 2019 (COVID-19). Studies with people with persistent symptoms showed inconsistent outcomes. Cognition and emotion are important determinants in HRQoL, but few studies have examined their prognostic significance for HRQoL and functionality in post-COVID patients with persisting symptoms. We aimed to describe QoL, HRQoL, and functioning in individuals post-COVID with varying COVID-19 severities and to investigate the predictive value of cognitive and emotional variables for QoL, HRQoL, and functioning.

METHODS

In total, 492 participants (398 post-COVID and 124 healthy controls) underwent a neurobehavioral examination that included assessments of cognition, mood, QoL/HRQoL (WHOQOL-BREF, EQ-5D), and functioning (WHODAS-II). Analysis of covariance and linear regression models were used to study intergroup differences and the relationship between cognitive and emotional variables and QoL and functioning.

RESULTS

The Physical and Psychological dimensions of WHOQoL, EQ-5D, and WHODAS Cognition, Mobility, Life Activities, and Participation dimensions were significantly lower in post-COVID groups compared with a control group. Regression models explaining 23.9%-53.9% of variance were obtained for the WHOQoL-BREF dimensions and EQ-5D, with depressive symptoms, post-COVID symptoms, employment status, income, and mental speed processing as main predictors. For the WHODAS, models explaining 17%-60.2% of the variance were obtained. Fatigue, depressive symptoms, mental speed processing, and post-COVID symptoms were the main predictors.

INTERPRETATION

QoL/HRQoL and functioning after COVID-19 in individuals with persistent symptoms were lower than in non-affected persons. Depressive symptoms, fatigue, and slower mental processing speed were predictors of lower QoL/HRQoL and functioning.

Cognitive reserve, depressive symptoms, obesity, and change in employment status predict mental processing speed and executive function after COVID-19

The risk factors for post-COVID-19 cognitive impairment have been poorly described. This study aimed to identify the sociodemographic, clinical, and lifestyle characteristics that characterize a group of post-COVID-19 condition (PCC) participants with neuropsychological impairment. The study sample included 426 participants with PCC who underwent a neurobehavioral evaluation. We selected seven mental speed processing and executive function variables to obtain a data-driven partition. Clustering algorithms were applied, including K-means, bisecting K-means, and Gaussian mixture models. Different machine learning algorithms were then used to obtain a classifier able to separate the two clusters according to the demographic, clinical, emotional, and lifestyle variables, including logistic regression with least absolute shrinkage and selection operator (LASSO) (L1) and Ridge (L2) regularization, support vector machines (linear/quadratic/radial basis function kernels), and decision tree ensembles (random forest/gradient boosting trees). All clustering quality measures were in agreement in detecting only two clusters in the data based solely on cognitive performance. A model with four variables (cognitive reserve, depressive symptoms, obesity, and change in work situation) obtained with logistic regression with LASSO regularization was able to classify between good and poor cognitive performers with an accuracy and a weighted averaged precision of 72%, a recall of 73%, and an area under the curve of 0.72. PCC individuals with a lower cognitive reserve, more depressive symptoms, obesity, and a change in employment status were at greater risk for poor performance on tasks requiring mental processing speed and executive function. Study registration: www.ClinicalTrials.gov , identifier NCT05307575.

Body mass index, systemic inflammation and cognitive performance in adolescents: A cross-sectional study

BACKGROUND

Excessive body weight has been related to lower cognitive performance. One of the mechanisms through which excess body weight may affect cognition is inflammation.

HYPOTHESIS

Our hypothesis is that both body mass index (BMI) and circulating levels of inflammatory biomarkers will be negatively related to cognitive performance.

DESIGN

Cross-sectional study.

SETTING

Users of the public health centres of the Consorci Sanitari de Terrassa (Terrassa, Spain) between 2010 and 2017 aged 12-21 years.

PARTICIPANTS

One hundred and five adolescents (46 normoweight, 18 overweight, 41 obese).

MEASUREMENTS

Levels of high sensitivity C-reactive protein, interleukin 6, tumour necrosis factor α (TNFα) and fibrinogen were determined from blood samples. Cognitive performance was evaluated and six cognitive composites were obtained: working memory, cognitive flexibility, inhibitory control, decision-making, verbal memory, and fine motor speed. A single multivariate general lineal model was used to assess the influence of the four inflammatory biomarkers, as well as participants' BMI, sex, and age on the 6 cognitive indexes.

RESULTS

An inverse relationship between BMI and inhibitory control (F = 5.688, p = .019; β = -0.212, p = .031), verbal memory (F = 5.404, p = .022; β = -0.255, p = .009) and fine motor speed (F = 9.038, p = .003; β = -0.319, p = .001) was observed. Levels of TNFα and fibrinogen were inversely related to inhibitory control (F = 5.055, p = .027; β = -0.226, p = .021) and verbal memory (F = 4.732, p = .032; β = -0.274, p = .005), respectively.

LIMITATIONS

The cross-sectional nature of the study, the use of cognitive tests designed for clinical purposes, and the use of BMI as a proxy for adiposity are limitations of our study that must be taken into account when interpreting results.

CONCLUSIONS

Our data indicate that some components of executive functions, together with verbal memory, are sensitive to specific obesity-related inflammatory agents at early ages.

Eye movements in patients with post-COVID condition

Eye movement control is impaired in some neurological conditions, but the impact of COVID-19 on eye movements remains unknown. This study aims to investigate differences in oculomotor function and pupil response in individuals who suffer post-COVID-19 condition (PCC) with cognitive deficits. Saccades, smooth pursuit, fixation, vergence and pupillary response were recorded using an eye tracker. Eye movements and pupil response parameters were computed. Data from 16 controls, 38 COVID mild (home recovery) and 19 COVID severe (hospital admission) participants were analyzed. Saccadic latencies were shorter in controls (183 ± 54 ms) than in COVID mild (236 ± 83 ms) and COVID severe (227 ± 42 ms) participants (p = 0.017). Fixation stability was poorer in COVID mild participants (Bivariate Contour Ellipse Area of 0.80 ± 1.61°2 vs 0.36 ± 0.65 °2 for controls, p = 0.019), while percentage of pupil area reduction/enlargement was reduced in COVID severe participants (39.7 ± 12.7%/31.6 ± 12.7% compared to 51.7 ± 22.0%/49.1 ± 20.7% in controls, p < 0.015). The characteristics of oculomotor alterations found in PCC may be useful to understand different pathophysiologic mechanisms.

COVID-19 severity is related to poor executive function in people with post-COVID conditions

Patients with post-coronavirus disease 2019 (COVID-19) conditions typically experience cognitive problems. Some studies have linked COVID-19 severity with long-term cognitive damage, while others did not observe such associations. This discrepancy can be attributed to methodological and sample variations. We aimed to clarify the relationship between COVID-19 severity and long-term cognitive outcomes and determine whether the initial symptomatology can predict long-term cognitive problems. Cognitive evaluations were performed on 109 healthy controls and 319 post-COVID individuals categorized into three groups according to the WHO clinical progression scale: severe-critical (n = 77), moderate-hospitalized (n = 73), and outpatients (n = 169). Principal component analysis was used to identify factors associated with symptoms in the acute-phase and cognitive domains. Analyses of variance and regression linear models were used to study intergroup differences and the relationship between initial symptomatology and long-term cognitive problems. The severe-critical group performed significantly worse than the control group in general cognition (Montreal Cognitive Assessment), executive function (Digit symbol, Trail Making Test B, phonetic fluency), and social cognition (Reading the Mind in the Eyes test). Five components of symptoms emerged from the principal component analysis: the "Neurologic/Pain/Dermatologic" "Digestive/Headache", "Respiratory/Fever/Fatigue/Psychiatric" and "Smell/ Taste" components were predictors of Montreal Cognitive Assessment scores; the "Neurologic/Pain/Dermatologic" component predicted attention and working memory; the "Neurologic/Pain/Dermatologic" and "Respiratory/Fever/Fatigue/Psychiatric" components predicted verbal memory, and the "Respiratory/Fever/Fatigue/Psychiatric," "Neurologic/Pain/Dermatologic," and "Digestive/Headache" components predicted executive function. Patients with severe COVID-19 exhibited persistent deficits in executive function. Several initial symptoms were predictors of long-term sequelae, indicating the role of systemic inflammation and neuroinflammation in the acute-phase symptoms of COVID-19." Study Registration: www.ClinicalTrials.gov , identifier NCT05307549 and NCT05307575.

Influence of Executive Function Training on BMI, Food Choice, and Cognition in Children with Obesity: Results from the TOuCH Study

BACKGROUND

Children with obesity have a higher risk of future health and psychological problems. Executive functions (EFs) play a key role in successful dietetic and exercise planning; therefore, new treatments aimed at improving EFs may optimize outcomes.

OBJECTIVES

This study evaluates the impact of EF training on body mass index (BMI), food choice, and cognition in children with obesity. We also examine their real-life executive functioning, emotional state, and quality of life.

METHODS

Randomized controlled double-blind trial. Forty-six children with obesity were randomly allocated into an executive functions training or a control task training group and attended 30-45 min of daily training (5/week over 6 weeks), with both groups receiving counseling on diet and wearing an activity/sleep tracker. Participants were evaluated at baseline and after treatment.

RESULTS

BMI decreased over time in the whole sample, although there were no differences between groups at post-training in BMI, food choice, and cognition. Both groups showed significant improvements in attention, speed, cognitive flexibility, and inhibitory control. Additionally, there were some benefits in real-life executive functioning and self-esteem. Over the 6 weeks, participants showed worse food choices in both groups.

CONCLUSIONS

EFs training showed a lack of significant effects. The executive function enhancement alone did not explain these changes, as there were no significant differences between the experimental groups. It might be that the control task training could also produce some benefits, and multi-component interventions might be useful for weight loss.

Neuropsychological impairment in post-COVID condition individuals with and without cognitive complaints

One of the most prevalent symptoms of post-COVID condition is cognitive impairment, which results in a significant degree of disability and low quality of life. In studies with large sample sizes, attention, memory, and executive function were reported as long-term cognitive symptoms. This study aims to describe cognitive dysfunction in large post-COVID condition individuals, compare objective neuropsychological performance in those post-COVID condition individuals with and without cognitive complaints, and identify short cognitive exams that can differentiate individuals with post-COVID symptoms from controls. To address these aims, the Nautilus project was started in June 2021. During the first year, we collected 428 participants' data, including 319 post-COVID and 109 healthy controls (18-65 years old) from those who underwent a comprehensive neuropsychological battery for cognitive assessment. Scores on tests assessing global cognition, learning and long-term memory, processing speed, language and executive functions were significantly worse in the post-COVID condition group than in healthy controls. Montreal Cognitive Assessment, digit symbol test, and phonetic verbal fluency were significant in the binomial logistic regression model and could effectively distinguish patients from controls with good overall sensitivity and accuracy. Neuropsychological test results did not differ between those with and without cognitive complaints. Our research suggests that patients with post-COVID conditions experience significant cognitive impairment and that routine tests like the Montreal Cognitive Assessment, digit symbol, and phonetic verbal fluency test might identify cognitive impairment. Thus, the administration of these tests would be helpful for all patients with post-COVID-19 symptoms, regardless of whether cognitive complaints are present or absent.

STUDY REGISTRATION

www.ClinicalTrials.gov, identifiers NCT05307549 and NCT05307575.

Preserved central nervous system functioning after use of romidepsin as a latency-reversing agent in an HIV cure strategy

OBJECTIVE

To assess the central nervous system (CNS) impact of a kick&kill HIV cure strategy using therapeutic vaccine MVA.HIVconsv and the histone deacetylase inhibitor (HDACi) romidepsin (RMD) as latency-reversing agent.

DESIGN

Neurological observational substudy of the BCN02 trial (NCT02616874), a proof-of-concept, open-label, single-arm, phase I clinical trial testing the safety and immunogenicity of the MVA.HIVconsv vaccine and RMD in early-treated HIV-1-infected individuals. A monitored antiretroviral pause (MAP) was performed, with cART resumption after 2 pVL more than 2000 copies/ml. Reinitiated participants were followed for 24 weeks.

METHODS

Substudy participation was offered to all BCN02 participants (N = 15). Evaluations covered cognitive, functional, and brain imaging outcomes, performed before RMD administration (pre-RMD), after three RMD infusions (post-RMD), and at the end of the study (EoS). A group of early-treated HIV-1-infected individuals with matched clinical characteristics was additionally recruited (n = 10). Primary endpoint was change in a global cognitive score (NPZ-6).

RESULTS

Eleven participants from BCN02 trial were enrolled. No significant changes were observed in cognitive, functional, or brain imaging outcomes from pre-RMD to post-RMD. No relevant alterations were detected from pre-RMD to EoS either. Scores at EoS were similar in participants off cART for 32 weeks (n = 3) and those who resumed therapy for 24 weeks (n = 7). Controls showed comparable punctuations in NPZ-6 across all timepoints.

CONCLUSION

No detrimental effects on cognitive status, functional outcomes, or brain imaging parameters were observed after using the HDACi RMD as latency-reversing agent with the MVA.HIVconsv vaccine in early-treated HIV-1-infected individuals. CNS safety was also confirmed after completion of the MAP.

The Impact of COVID-19 Confinement on Cognition and Mental Health and Technology Use Among Socially Vulnerable Older People: Retrospective Cohort Study

Background

COVID-19 forced the implementation of restrictive measures in Spain, such as lockdown, home confinement, social distancing, and isolation. It is necessary to study whether limited access to basic services and decreased family and social support could have deleterious effects on cognition, quality of life, and mental health in vulnerable older people.

Objective

This study aims to explore the impact of the COVID-19 outbreak on cognition in older adults with mild cognitive impairment or dementia as the main outcome and the quality of life, perceived health status, and depression as secondary outcomes and to analyze the association of living alone and a change in living arrangements with those outcomes and other variables related with the use of technology and health services. Likewise, this study aims to analyze the association of high and low technophilia with those variables, to explore the access and use of health care and social support services, and, finally, to explore the informative-, cognitive-, entertainment-, and socialization-related uses of information and communications technologies (ICTs) during the COVID-19 outbreak.

Methods

This cohort study was conducted in Málaga (Spain). In total, 151 participants with mild cognitive impairment or mild dementia, from the SMART4MD (n=75, 49.7%) and TV-AssistDem (n=76, 50.3%) randomized clinical trials, were interviewed by telephone between May 11 and June 26, 2020. All participants had undergone 1-3 assessments (in 6-month intervals) on cognition, quality of life, and mood prior to the COVID-19 breakout.

Results

The outbreak did not significantly impact the cognition, quality of life, and mood of our study population when making comparisons with baseline assessments prior to the outbreak. Perceived stress was reported as moderate during the outbreak. After correction for multiple comparisons, living alone, a change in living arrangements, and technophilia were not associated with negative mental health outcomes. However, being alone was nominally associated with self-perceived fear and depression, and higher technophilia with better quality of life, less boredom, perceived stress and depression, and also less calmness. Overall, health care and social support service access and utilization were high. The most used ICTs during the COVID-19 outbreak were the television for informative, cognitive, and entertainment-related uses and the smartphone for socialization.

Conclusions

Our findings show that the first months of the outbreak did not significantly impact the cognition, quality of life, perceived health status, and depression of our study population when making comparisons with baseline assessments prior to the outbreak. Living alone and low technophilia require further research to establish whether they are risk factors of mental health problems during lockdowns in vulnerable populations. Moreover, although ICTs have proven to be useful for informative-, cognitive-, entertainment-, and socialization-related uses during the pandemic, more evidence is needed to support these interventions.

Trial Registration

ClinicalTrials.gov NCT04385797; https://clinicaltrials.gov/ct2/show/NCT04385797

International Registered Report Identifier (IRRID)

RR2-10.2196/26431

Alterations in Brain Network Organization in Adults With Obesity as Compared With Healthy-Weight Individuals and Seniors

OBJECTIVE

Life expectancy and obesity rates have drastically increased in recent years. An unhealthy weight is related to long-lasting medical disorders that might compromise the normal course of aging. The aim of the current study of brain connectivity patterns was to examine whether adults with obesity would show signs of premature aging, such as lower segregation, in large-scale networks.

METHODS

Participants with obesity (n = 30, mean age = 32.8 ± 5.68 years) were compared with healthy-weight controls (n = 33, mean age = 30.9 ± 6.24 years) and senior participants who were stroke-free and without dementia (n = 30, mean age = 67.1 ± 6.65 years) using resting-state magnetic resonance imaging and graph theory metrics (i.e., small-world index, clustering coefficient, characteristic path length, and degree).

RESULTS

Contrary to our hypothesis, participants with obesity exhibited a higher clustering coefficient compared with senior participants (t = 5.06, p < .001, d = 1.23, 95% CIbca = 0.64 to 1.88). Participants with obesity also showed lower global degree relative to seniors (t = -2.98, p = .014, d = -0.77, 95% CIbca = -1.26 to -0.26) and healthy-weight controls (t = -2.92, p = .019, d = -0.72, 95% CIbca = -1.19 to -0.25). Regional degree alterations in this group were present in several functional networks.

CONCLUSIONS

Participants with obesity displayed greater network clustering than did seniors and also had lower degree compared with seniors and individuals with normal weight, which is not consistent with the notion that obesity is associated with premature aging of the brain. Although the cross-sectional nature of the study precludes causal inference, the overly clustered network patterns in obese participants could be relevant to age-related changes in brain function because regular networks might be less resilient and metabolically inefficient.

Restrained Eating Is Associated with Lower Cortical Thickness in the Inferior Frontal Gyrus in Adolescents

Some eating patterns, such as restrained eating and uncontrolled eating, are risk factors for eating disorders. However, it is not yet clear whether they are associated with neurocognitive differences. In the current study, we analyzed whether eating patterns can be used to classify participants into meaningful clusters, and we examined whether there are neurocognitive differences between the clusters. Adolescents (n = 108; 12 to 17 years old) and adults (n = 175, 18 to 40 years old) completed the Three Factor Eating Questionnaire, which was used to classify participants according to their eating profile using k means clustering. Participants also completed personality questionnaires and a neuropsychological examination. A subsample of participants underwent a brain MRI acquisition. In both samples, we obtained a cluster characterized by high uncontrolled eating patterns, a cluster with high scores in restrictive eating, and a cluster with low scores in problematic eating behaviors. The clusters were equivalent with regards to personality and performance in executive functions. In adolescents, the cluster with high restrictive eating showed lower cortical thickness in the inferior frontal gyrus compared to the other two clusters. We hypothesize that this difference in cortical thickness represents an adaptive neural mechanism that facilitates inhibition processes.

Associations Between Mobile Health Technology use and Self-rated Quality of Life: A Cross-sectional Study on Older Adults with Cognitive Impairment

Background: Quality of life (QoL) is affected even at early stages in older adults with cognitive impairment. The use of mobile health (mHealth) technology can offer support in daily life and improve the physical and mental health of older adults. However, a clarification of how mHealth technology can be used to support the QoL of older adults with cognitive impairment is needed. Objective: To investigate factors affecting mHealth technology use in relation to self-rated QoL among older adults with cognitive impairment. Methods: A cross-sectional research design was used to analyse mHealth technology use and QoL in 1,082 older participants. Baseline data were used from a multi-centered randomized controlled trial including QoL, measured by the Quality of Life in Alzheimer’s Disease (QoL-AD) Scale, as the outcome variable. Data were analyzed using logistic regression models. Results: Having moderately or high technical skills in using mHealth technology and using the internet via mHealth technology on a daily or weekly basis was associated with good to excellent QoL in older adults with cognitive impairment. Conclusions: The variation in technical skills and internet use among the participants can be interpreted as an obstacle for mHealth technology to support QoL.

Executive Function Training in Childhood Obesity: Food Choice, Quality of Life, and Brain Connectivity (TOuCH): A Randomized Control Trial Protocol

Background: Individuals with obesity are known to present cognitive deficits, especially in executive functions. Executive functions play an important role in health and success throughout the whole life and have been related to food decision-making and to the ability to maintain energy balance. It is possible to improve executive functions through targeted training. This would involve brain plasticity changes that could be studied through connectivity MRI. The general hypothesis of this study is that executive functions training in children with obesity can improve food choices and produce cognitive and neuroimaging changes (structural and functional connectivity), as well as improve emotional state and quality of life. Methods: Randomized controlled double-blind trial with 12-month follow-up. Thirty children with obesity will be randomly allocated into "executive training" (Cognifit with adaptive difficulty + Cogmed) or "control task" group (Cognifit without adaptive difficulty). Both groups will attend 30-45 min of individual gamified training (Cogmed and/or Cognifit systems) by iPad, five times per week during 6 weeks. Cogmed and Cognifit software are commercially available from Pearson and Cognifit, respectively. Participants will receive an iPad with both apps installed for a 6-week use. Participants will also receive counseling diet information via presentations sent to the iPad and will wear a Fitbit Flex 2 tracker to monitor daily activity and sleep patterns. Main outcomes will be cognitive, emotional, food decision, and quality-of-life measures, as well as neuroimaging measures. Participants are evaluated at baseline (T0), after treatment (T1), and 12 months since baseline (T2). Discussion: Longitudinal study with active control group and 3 time points: baseline, immediately after treatment, and 1 year after baseline. Threefold treatment: executive function training, psychoeducation, and feedback on activity/sleep tracking. We will evaluate the transfer effects of the intervention, including emotional and functional outcomes, as well as the effects on neural plasticity by connectivity MRI. Trial registration: This project has been registered in ClinicalTrials.gov (trial registration number NCT03615274), August 3, 2018.

Is cognitive training an effective tool for improving cognitive function and real-life behaviour in healthy children and adolescents? A systematic review

Computerised cognitive training (CCT) has been applied to improve cognitive function in pathological conditions and in healthy populations. Studies suggest that CCT produces near-transfer effects to cognitive functions, with less evidence for far-transfer. Newer applications of CTT in adults seem to produce certain far-transfer effects by influencing eating behaviour and weight loss. However, this is more unexplored in children and adolescents. We conducted a systematic review of 16 studies with randomised controlled design to assess the impact of CCT on cognitive functioning and real-life outcomes, including eating behaviour, in children and adolescents with typical development (PROSPERO registration number: CRD42019123889). Results show near-transfer effects to working memory, with inconsistent results regarding far-transfer effects to other cognitive functions and real-life measures. Long-term effects show the same trend. Far-transfer effects occurred after cue-related inhibitory control and attentional training, although effects seem not to last. CCT may be a potential weight-loss treatment option but more research is needed to determine the specific characteristics to enhance treatment outcomes.

Attitudes and Use of Information and Communication Technologies in Older Adults With Mild Cognitive Impairment or Early Stages of Dementia and Their Caregivers: Cross-Sectional Study

Background

Information and communication technologies are promising tools to increase the quality of life of people with dementia or mild cognitive impairment and that of their caregivers. However, there are barriers to their use associated with sociodemographic factors and negative attitudes, as well as inadequate knowledge about technologies.

Objective

The aim of this study was to analyze technophilia (attitudes toward new technologies) and the use of smartphones and tablets along with associated factors in people with dementia/mild cognitive impairment and their caregivers.

Methods

Data from the first visit of the Support Monitoring and Reminder for Mild Dementia (SMART4MD) randomized multicenter clinical trial were used for this analysis. Data were obtained from two European countries, Spain and Sweden, and from three centers: Consorci Sanitari de Terrassa (Catalonia, Spain), Servicio Andaluz de Salud (Andalusia, Spain), and the Blekinge Institute of Technology (Sweden). Participants with a score between 20 and 28 in the Mini Mental State Examination, with memory problems (for more than 6 months), and who were over the age of 55 years were included in the study, along with their caregivers. The bivariate Chi square and Mann-Whitney tests, and multivariate linear and logistic regression models were used for statistical analysis.

Results

A total of 1086 dyads were included (N=2172). Overall, 299 (27.53%) of people with dementia/mild cognitive impairment had a diagnosis of dementia. In addition, 588 (54.14%) of people with dementia/mild cognitive impairment reported using a smartphone almost every day, and 106 (9.76%) used specific apps or software to support their memory. Among the caregivers, 839 (77.26%) used smartphones and tablets almost every day, and 181 (16.67%) used specific apps or software to support their memory. The people with dementia/mild cognitive impairment showed a lower level of technophilia in comparison to that of their caregivers after adjusting for confounders (B=0.074, P=.02) with differences in technology enthusiasm (B=0.360, P<.001), but not in technology anxiety (B=–0.042, P=.37). Technophilia was associated with lower age (B=–0.009, P=.004), male gender (B=–0.160, P<.001), higher education level (P=.01), living arrangement (living with children vs single; B=–2.538, P=.01), country of residence (Sweden vs Spain; B=0.256, P<.001), lower depression (B=–0.046, P<.001), and better health status (B=0.004, P<.001) in people with dementia/mild cognitive impairment. Among caregivers, technophilia was associated with comparable sociodemographic factors (except for living arrangement), along with a lower caregiver burden (B=–0.005, P=.04) and better quality of life (B=0.348, P<.001).

Conclusions

Technophilia was associated with a better quality of life and sociodemographic variables in people with dementia/mild cognitive impairment and caregivers, suggesting potential barriers for technological interventions. People with dementia/mild cognitive impairment frequently use smartphones and tablets, but the use of specific apps or software to support memory is limited. Interventions using these technologies are needed to overcome barriers in this population related to sociodemographic characteristics and the lack of enthusiasm for new technologies.

Trial Registration

ClinicalTrials.gov NCT03325699; https://clinicaltrials.gov/ct2/show/NCT03325699

The Effects of Exposure to Recent Autobiographical Events on Declarative Memory in Amnestic Mild Cognitive Impairment: A Preliminary Pilot Study

BACKGROUND

Individuals with amnestic Mild Cognitive Impairment (aMCI) are at heightened risk of developing Alzheimer's dementia. In recent years, much attention has been given to the search for new interventions to slow down the progression of cognitive decline of these patients. Wearable digital camera devices are one form of new technology that captures images of one's life events, so they constitute a promising method to be used as a means to stimulate recent autobiographical memory.

OBJECTIVE

This preliminary study investigates the ability of a new cognitive intervention based on exposure to recent autobiographical memory captured by wearable cameras to improve episodic memory in patients with aMCI.

METHODS

Seventeen subjects wore a wearable camera while they went about their daily activities. The images captured were converted into eight different 3-minute films containing the most relevant information of each event. The intervention involved eight individualized weekly sessions during which patients were exposed to a different autobiographical event each week. Besides, several specific questions were formulated within each session. Clinical questionnaires assessing cognitive reserve, premorbid intelligence, depression, and anxiety were administered at baseline. Measures of objective episodic memory were applied at baseline and at post-treatment.

RESULTS

Significant improvements were observed at post-treatment in memory measures, and significant associations were found between memory change scores and age and cognitive reserve. Anyway, these associations did not reach statistical significance after adjusting for multiple comparisons.

CONCLUSION

The present study provides preliminary evidence that aMCI patients may benefit from a cognitive intervention program based on re-experiencing recent autobiographical events. However, future studies incorporating a control group will be needed to confirm these preliminary findings.

NEU Screen Shows High Accuracy in Detecting Cognitive Impairment in Older Persons Living With HIV

The NEUrocognitive (NEU) Screen is a practical tool proposed to screen for HIV-associated cognitive impairment in the clinical setting. This is a pencil-and-paper method that can be applied rapidly (≤10 minutes for administration) and has no copyright limitations. In this study, we aimed at investigating its diagnostic accuracy in an older population of persons living with HIV (PLWH), with cutoffs set at 30, 40, 50, and 60 years. Data were collected from a sample of 368 PLWH who underwent a comprehensive neuropsychological tests battery (gold standard). Results of statistical tests showed that accuracy of the NEU Screen increased with age of the participants. The highest degree of precision, with a sensitivity of 91% and specificity of 92%, was obtained for people ages 60 years or older (correct classification: 91%). These optimal results point to the great potential of the NEU Screen as a tool for detecting cognitive disorders in older PLWH.

Allostatic load and executive functions in overweight adults

BACKGROUND/OBJECTIVE

Overweight is linked to inflammatory and neuroendocrine responses potentially prompting deregulations in biological systems harmful to the brain, particularly to the prefrontal cortex. This structure is crucial for executive performance, ultimately supervising behaviour. Thus, in the present work, we aimed to test the relationship between allostatic load increase, a surrogate of chronic physiological stress, and core executive functions, such as cognitive flexibility, inhibitory control, and working memory.

METHOD

Forty-seven healthy-weight and 56 overweight volunteers aged from 21 to 40 underwent medical and neuropsychological examination.

RESULTS

Overweight subjects exhibited a greater allostatic load index than healthy-weight individuals. Moreover, the allostatic load index was negatively related to inhibitory control. When separated, the link between allostatic load index and cognitive flexibility was more marked in the overweight group.

CONCLUSIONS

An overweight status was linked to chronic physiological stress. The inverse relationship between the allostatic load index and cognitive flexibility proved stronger in this group. Set-shifting alterations could sustain rigid-like behaviours and attitudes towards food.

The Effects of the Digital Platform Support Monitoring and Reminder Technology for Mild Dementia (SMART4MD) for People With Mild Cognitive Impairment and Their Informal Carers: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

Many countries are witnessing a trend of growth in the number and proportion of older adults within the total population. In Europe, population aging has had and will continue to have major social and economic consequences. This is a fundamentally positive development where the added life span is of great benefit for both the individual and the society. Yet, the risk for the individual to contract noncommunicable diseases and disability increases with age. This may adversely affect the individual's ability to live his or her life in the way that is desired. Cognitive conditions constitute a group of chronic diseases that predominantly affects older people. Recent technology advancements can help support the day-to-day living activities at home for people with cognitive impairments.

OBJECTIVE

A digital platform (Support Monitoring and Reminder for Mild Dementia; SMART4MD) is created to improve or maintain the quality of life for people with mild cognitive impairment (PwMCI) and their carers. The platform will provide reminders, information, and memory support in everyday life, with the purpose of giving structure and lowering stress. In the trial, we will include participants with a diagnosed neurocognitive disorder as well as persons with an undiagnosed subjective memory problem and cognitive impairment, that is, 20 to 28 points on the Mini-Mental State Examination.

METHODS

A pragmatic, multicenter RCT is being conducted in Spain, Sweden, and Belgium. The targets for recruitment are 1200 dyads-split into an intervention group and a control group that are in usual care. Intervention group participants will be provided with a data-enabled computer tablet with the SMART4MD app. Its core functionalities, intended to be used daily at home, are based on reminders, cognitive supporting activities, and sharing health information.

RESULTS

Inclusion of participants started in December 2017, and recruitment is expected to end in February 2019. Furthermore, there will be 3 follow-up visits at 6, 12, and 18 months after the baseline visit.

CONCLUSIONS

This RCT is expected to offer benefits at several levels including in-depth knowledge of the possibilities of introducing a holistic multilayered information and communication technology solution for this group. SMART4MD has been developed in a process involving the structured participation of PwMCI, their informal carers, and clinicians. The adoption of SMART4MD faces the challenge of this age group's relative unfamiliarity with digital devices and services. However, this challenge can also be an opportunity for developing a digital device tailored to a group at risk of digital exclusion. This research responds to the wider call for the development of digital devices which are accessible and affordable to older people and this full scale RCT can hopefully serve as a model for further studies in this field.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03325699; https://clinicaltrials.gov/ct2/show/NCT03325699.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/13711.

Acceptability of a lifelogging wearable camera in older adults with mild cognitive impairment: a mixed-method study

BACKGROUND

The main objective of this research was to evaluate the acceptance of technology based on a wearable lifelogging camera in a sample of older adults diagnosed with mild cognitive impairment (MCI).

METHODS

A mixed-method design was used, consisting of a self-report questionnaire, numerous images taken by users, and a series of focus group discussions. The patients were involved in an individualized training programme.

RESULTS

Nine MCI patients and their caregiver relatives were included. They showed good acceptance of the camera and downloaded an appropriate number of images on a daily basis. Perceived severity and ease of use were the main factors associated with the intention to use the device.

CONCLUSIONS

Older adults with MCI can become competent users of lifelogging wearable cameras with a good level of acceptance. Privacy concerns are outweighed by the potential benefits for memory. Limitations, strengths and implications for future research are discussed.

Effect of the catechol-O-methyltransferase Val 158 Met polymorphism on theory of mind in obesity

Obesity is often accompanied with psychosocial adjustment problems, such as difficulties in social interactions and social withdrawal. A key aspect of social cognition is theory of mind, which allows inferring mental states, feelings, motivations, and beliefs of others and to use this information to predict their future behaviour. Theory of mind is highly dependent on prefrontal dopaminergic neurotransmission, which is regulated by catechol-O-methyltransferase (COMT) activity. We aimed at determining whether theory of mind is altered in obesity and if this ability is modulated by COMT. Fifty patients with obesity and 47 normal-weight individuals underwent the Reading the Mind in the Eyes Test, the Wisconsin Card Sorting Test, and the Vocabulary subscale of the Wechsler Adult Intelligence Scale. The genotype for the COMT Val ¹⁵⁸ Met functional polymorphism was determined for all subjects. Patients with obesity obtained significantly lower scores in the negative items of the Reading the Mind in the Eyes Test than normal-weight subjects. Further, an interaction effect was observed between group and COMT genotype. Specifically, the presence of the Met allele was associated to a better identification of negative mental states only in patients with obesity. Our results indicate that obesity is accompanied with difficulties in theory of mind and that this ability is influenced by the COMT genotype.

Cognitive impairment following chemotherapy for breast cancer: The impact of practice effect on results

Chemotherapy-Related Cognitive Impairment (CRCI) can be an adverse effect in women treated for breast cancer. Some longitudinal studies reported deficits in attention, memory, and executive function following treatment, but other studies did not find cognitive changes. It is known that practice effects (PE) on repeated assessments with cognitive tests contribute to the discrepancies in these results, but its influence on scores has not been systematically explored. The present study examines the impact of PE on retest scores in a group of women with breast cancer treated with chemotherapy and evaluated longitudinally.

METHOD

51 women with breast cancer treated with a combination of 5-fluorouracil, epirubicin, and cyclophosphamide with or without taxanes were assessed after surgery but before chemotherapy (T1), post-chemotherapy (T2), and at one year after T2 (T3). Longitudinal changes on cognitive performance were analyzed twice: when retest scores were not corrected for PE and when correction for PE was applied to T2 and T3 scores.

RESULTS

When PE was not corrected, progressive improvement over time in measures of memory and divided attention at T2 and T3 was observed. In contrast, when PE was corrected, worsening was found in measures of memory, fluency, executive function, and attention at T2 and in attention and executive function at T3. Results after correction for PE are in line with previous longitudinal studies that report cognitive impairment after treatment with chemotherapy for breast cancer.

CONCLUSION

Accounting for PE is recommended to identify true change on cognition through treatment with chemotherapy for breast cancer.

Allostatic load and disordered white matter microstructure in overweight adults

Overweight and stress are both related to brain structural abnormalities. The allostatic load model states that frequent disruption of homeostasis is inherently linked to oxidative stress and inflammatory responses that in turn can damage the brain. However, the effects of the allostatic load on the central nervous system remain largely unknown. The current study aimed to assess the relationship between the allostatic load and the composition of whole-brain white matter tracts in overweight subjects. Additionally, we have also tested for grey matter changes regarding allostatic load increase. Thirty-one overweight-to-obese adults and 21 lean controls participated in the study. Our results showed that overweight participants presented higher allostatic load indexes. Such increases correlated with lower fractional anisotropy in the inferior fronto-occipital fasciculi and the right anterior corona radiata, as well as with grey matter reductions in the left precentral gyrus, the left lateral occipital gyrus, and the right pars opercularis. These results suggest that an otherwise healthy overweight status is linked to long-term biological changes potentially harmful to the brain.

Transcranial magnetic stimulation intervention in Alzheimer's disease: a research proposal for a randomized controlled trial

Objective

Alzheimer’s disease is a major health problem in our society. To date, pharmacological treatments have obtained poor results and there is a growing interest in finding non-pharmacological interventions for this disease. Transcranial magnetic stimulation (TMS) is a non-invasive technique that is able to induce changes in brain activity and long-term modifications in impaired neural networks, becoming a promising clinical intervention. Our goal is to study the benefit of individualized TMS targeting based on the patient’s functional connectivity (personalized targeting), and short duration TMS protocol, instead of current non-individualized and longer session approaches. A double blind randomized controlled trial will be conducted to assess the effects of TMS treatment immediately, 1 month, 3 months and 6 months after the end of the intervention. Fifty-four patients with a diagnosis of Alzheimer’s disease will be randomly allocated into experimental (active TMS), sham control, or conventional intervention control group. We will quantify changes in cognitive, functional, and emotional deficits in Alzheimer patients, as well as the functional connectivity changes induced by the TMS treatment.

Results

We expect to demonstrate that personalized TMS intervention has a measurable positive impact in cognition, emotion, daily living activities and brain connectivity, thus representing a potential treatment for Alzheimer’s disease.

Trial registration The trial has been prospectively registered at ClinicalTrials.gov, identifier NCT03121066. Date of registration: 04/19/2017

The effect of depressive symptoms on cognition in patients with fibromyalgia

BACKGROUND

Fibromyalgia (FM) patients frequently complain of cognitive problems, but it remains unclear whether these cognitive complaints can be attributed to a dysfunction of the central nervous system or if they can be explained by other factors associated with the disease, such as depression, anxiety and sleep dysfunction.

METHODS

One hundred and ten patients with FM were compared with thirty-three patients diagnosed with a depressive disorder (DD) and fifty healthy controls (HC). Several measures of attention and executive functions were used to make these comparisons and the patients were also asked to complete questionnaires on depression, anxiety and sleep quality. Univariate analyses of covariance (ANCOVA) were performed to identify and control confounders and multiple linear models were used to examine the effects of fibromyalgia and depression on cognitive measures.

RESULTS

FM and HC differed significantly with respect to depression, anxiety and sleep dysfunction, whereas FM and DD did not differ in terms of symptoms of depression and anxiety. However, FM was associated with a worse quality of sleep than DD. Comparisons of cognitive performance between groups showed that short-term and working memory and inattention measures were only associated with symptoms of depression, whereas selective attention was associated with both depression and fibromyalgia, and processing speed, cognitive flexibility and inhibitory control showed a significant interaction between depression and fibromyalgia. Moreover, cognitive flexibility and inhibition abilities were specifically associated with FM.

CONCLUSION

FM patients show a cluster of cognitive impairment in the attentional and executive domains, although some of the symptoms observed could be explained by the severity of the symptoms of depression, while others seem to depend on the effects of fibromyalgia. Implications of the findings for the understanding and management of cognitive impairment of FM patients are discussed.

Anxiety, hospital fears and conduct and behavioral alterations during pediatric hospitalization

INTRODUCTION

A hospital admission is an experience capable of generating emotional and behavioral alterations at any age. This study pretends to analyze the response of anxiety, fears and/or behavioral alterations in pediatric patients exposed to a conventional non-surgical hospital admission and the existing relationship between these responses and certain modulating variables. Metodology. Design of cohorts. Data collection was carried out in three stages (M1: at admission; M2: at discharge; M3: 2 weeks after discharge), on a 30 patient sample between the ages of 6 to 15 years and 30 caregivers. A comparison was made on the mean of the repeated measurements (Student t) of the respond variables and their correlation (Pearson&#8217;s Coefficient Correlation) with modulating variables.

RESULTS

The results of the intra-subject analysis showed significance in terms of anxiety levels state in patients in M1 versus M3 (t=3.93, p<.0001, d=0.69) and the magnitude of the total behavioral alterations registered in M1 versus M3 (t=-5.02, p<.0001, d=0.60). It was observed that a significant relationship between modulating variables of patients (anxiety risk) and of the caregiver (anxiety character state, strategy of confrontation) and the variables of response of the anxiety and behavioral alterations of the patient.

CONCLUSIONS

Exposure of a conventional non-surgical hospital admission may have negative consequences at an emotional and behavioral level in children, present far beyond the hospital admission. Certain variables, from the patient and the caregiver, are psychological vulnerability factors before a hospitalization process.

Relationship between neuropsychological tests and driver's license renewal tests in Parkinson's disease

OBJECTIVE

To determine whether the standard Spanish driving test (ASDE test) was able to identify patients with Parkinson's disease (PD) at risk of unsafe driving and to examine the relationship between the ASDE test and the Useful Field of View (UFOV) as well as with a battery of neuropsychological tests in drivers with PD.

METHODS

Thirty-seven patients with PD and 33 controls matched by age and education level were included in an observational study. All participants were active drivers and patients with PD underwent study procedures after taking the medication in the "on" period. Subjects with a Mini-Mental State Examination (MMSE) score ≤ 24 were excluded. Neuropsychological tests (Repeatable Battery for Neuropsychological Status [RBANS], Trail Making Test [TMT-A and -B], and Block Design test), driving performance tests (ASDE Driver Test and UFOV), and daytime sleepiness (Epworth Sleepiness Scale) were assessed.

RESULTS

The PD group performed significantly worse than healthy controls in the ASDE Motor Coordination tests. No significant differences were observed in anticipation speed, multiple reaction time, concentrated attention, and resistance to monotony. All participants successfully completed the UFOV tests. Statistically significant differences between patients with PD and controls were found in processing speed (UFOV1; P =.03) and more patients with PD were found in the categories of higher driving risk levels (P =.03). In addition, patients with PD showed worse scores than healthy controls in visuospatial capacities (Line Orientation), psychomotor speed (Coding and TMT-A), memory (List Recognition, Story Recall), and executive function (TMT-B). The driving tests (ASDE and UFOV) showed a low sensitivity and a high specificity but a higher percentage of patients in the PD group failed in multiple reaction time, concentrated attention, and resistance to monotony. In addition, 18.9% of patients with PD showed a cutoff of 4 for UFOV risk. In the discriminant analysis, Line Orientation (visuospatial/constructive domain) and Figure Recall (delayed memory) were found to be statistically significant with a rate of correct classification of unsafe drivers with PD of 78.2%. In addition, normal results on the Line Orientation item were associated with a 1.5 times higher probability of non-risky driving in the multivariate analysis.

CONCLUSIONS

At early stages of the disease, about 19% of patients with PD showed difficulties that may affect their driving capabilities. Line Orientation and Figure Recall are useful to alert clinicians to the risk of unsafe driving. For this reason, patients with PD should be evaluated for driving abilities more regularly to determine the extent of deficits that may influence driving performance.

Neuropsychological Outcome One Year after Carotid Revascularization: A before-and-after Study

Purpose

The aim of our study was to determine the clinical profile of patients considered cognitive 'responders' to surgery in order to establish clinical variables associated with a favorable cognitive performance.

Materials and Methods

A total of 70 patients were included in the study. A well-validated, comprehensive standardized neurocognitive battery of tests of about 2 hours was administered. Patients were examined twice, 1-week before surgery and 1-year postoperatively. The criterion to be included in the 'responder' group was the following: to obtain a positive difference between post-revascularization and pre-revascularization neuropsychological assessment ≥1 standard deviation in ≥2 tests.

Results

Twenty-seven patients (38.6%) were cognitive responders to treatment. In bivariate analysis between responders and non-responders, presence of atrophy (P=0.003), small vessels (P=0.577), symptoms (P=0.046), and age (P=0.030) were the factors statistically significant. When comparing cognitive performance before and after carotid revascularization, significant differences were observed in semantic fluency with a lower performance after 12 months (P=0.004, d=0.29), and in the Language index (Repeatable Battery for the Assessment of Neuropsychological Status) (P=0.005, d=0.34).

Conclusion

Patients without neurological symptoms, of a younger age and without atrophy and white matter small vessel lesions are better cognitive responders 1-year after carotid revascularization.

Allostatic Load Is Linked to Cortical Thickness Changes Depending on Body-Weight Status

Objective: Overweight (body mass index or BMI ≥ 25 kg/m²) and stress interact with each other in complex ways. Overweight promotes chronic low-inflammation states, while stress is known to mediate caloric intake. Both conditions are linked to several avoidable health problems and to cognitive decline, brain atrophy, and dementia. Since it was proposed as a framework for the onset of mental illness, the allostatic load model has received increasing attention. Although changes in health and cognition related to overweight and stress are well-documented separately, the association between allostatic load and brain integrity has not been addressed in depth, especially among overweight subjects.

Method: Thirty-four healthy overweight-to-obese and 29 lean adults underwent blood testing, neuropsychological examination, and magnetic resonance imaging to assess the relationship between cortical thickness and allostatic load, represented as an index of 15 biomarkers (this is, systolic and diastolic arterial tension, glycated hemoglobin, glucose, creatinine, total cholesterol, HDL and LDL cholesterol, triglycerides, c-reactive protein, interleukin-6, insulin, cortisol, fibrinogen, and leptin).

Results: Allostatic load indexes showed widespread positive and negative significant correlations (p < 0.01) with cortical thickness values depending on body-weight status.

Conclusion: The increase of allostatic load is linked to changes in the gray matter composition of regions monitoring behavior, sensory-reward processing, and general cognitive function.

Transdermal rivastigmine for HIV-associated cognitive impairment: A randomized pilot study

Objective

To assess the efficacy and safety of transdermal rivastigmine for the treatment of HIV-associated cognitive impairment.

Methods

We recruited HIV-infected patients with cognitive impairment on stable antiretroviral therapy in a randomized controlled pilot trial with a 48-week follow-up. An additional assessment was held at 12 weeks. Participants received transdermal rivastigmine (9.5 mg daily), lithium (400 mg twice daily, titrated progressively), or remained in a control group (no new medication). The primary efficacy endpoint was change in a global cognitive score (NPZ-7). Secondary endpoints included change in specific cognitive measures, domains, and functional parameters. Safety covered the frequency of adverse events and changes in laboratory results.

Results

Seventy-six subjects were screened, and 29 were finally enrolled. Better cognitive outcomes were observed in all groups, although there were no significant differences between the arms (mean NPZ-7 change [SD]): rivastigmine, 0.35 (0.14); lithium, 0.25 (0.40); control, 0.20 (0.44) (p = 0.78). The rivastigmine group showed the highest positive trend (mean NPZ-7 [SD], baseline vs week 48): rivastigmine, –0.47 (0.22) vs –0.11 (0.29), p = 0.06; lithium, –0.50 (0.40) vs –0.26 (0.21), p = 0.22; control, –0.52 (0.34) vs –0.32 (0.52), p = 0.44. The cognitive domains with the highest positive trends were information processing speed at week 12 and executive function at week 48 (rivastigmine vs control): information processing speed, 0.35 (0.64) vs –0.13 (0.25), p = 0.17, d = 0.96; and executive functioning, 0.73 (0.33) vs 0.03 (0.74), p = 0.09, d = 1.18. No relevant changes were observed regarding functional outcomes. A total of 12 (41%) individuals dropped out of the study: 2 (20%) were due to medication-related effects in the rivastigmine group and 4 (36%) in the lithium group. No severe adverse events were reported.

Conclusions

The results from this small randomized trial indicate that transdermal rivastigmine did not provide significant cognitive benefits in people with HAND on stable antiretroviral therapy, even though positive trends were found in specific cognitive domains. Relevant tolerability issues were not observed.

Long-term far-transfer effects of working memory training in children with ADHD: a randomized controlled trial

ADHD affects working memory (WM) and other executive functions (EFs) and thereby negatively impacts school performance, clinical symptoms and functional impairment. The main aim of this study was to analyse the efficacy of computerized WM training (CWMT) on EF rating scales. A secondary objective was to assess its efficacy on performance-based measures of EF (PBMEF), learning, clinical symptoms and functional impairment. 66 children with combined-type ADHD between 7 and 12 years of age from the Child and Adolescent Psychiatric Unit (Spain) were included in this randomized, double-blind, placebo-controlled, parallel-group clinical trial. The participants were randomized (1:1) to an experimental group (EG) (CWMT) (n = 36) or a control group (CG) (placebo training). Assessments were conducted at baseline (T0), 1-2 weeks (T1), and 6 months post-intervention (T2) with the administration of EF rating scales, PBMEF, measures of academic achievement, and questionnaires regarding clinical symptoms and functional impairment. Participants, parents, teachers and professionals who performed the cognitive assessments were blinded. Adjusted multiple linear regression analysis showed significant improvements in EF scales-parent version, from T1 to T2, on the metacognition index [p = 0.03, d' = -0.78 (95 % CI -1.28 to -0.27)] and on WM (also significant at T2-T0) and plan/organize subscales. Significant improvements were also noted in EF scales-teacher version, from T0 to T1 and T2, on the metacognitive index [p = 0.05, d' = -0.37 (95 % CI -0.86 to 0.12) T1-T0, p = 0.02, d' = -0.81 (95 % CI -1.31 to -0.30) T2-T0] and on the initiate, WM, monitor and shift subscales. There were also significant improvements in PBMEF, ADHD symptoms, and functional impairment. CWMT had a significant impact on ADHD deficits by achieving long-term far-transfer effects.

Executive function in fibromyalgia: Comparing subjective and objective measures

BACKGROUND

There is evidence to suggest the existence of an executive dysfunction in people diagnosed with fibromyalgia, although there are certain inconsistencies between studies. Here, we aim to compare executive performance between patients with fibromyalgia and a control group by using subjective and objective cognitive tests, analyzing the influence of patient mood on the results obtained, and studying associations between the two measures.

METHOD

82 patients diagnosed with fibromyalgia and 42 healthy controls, matched by age and years of education, were assessed using the Behavioral Rating Inventory of Executive Function - Adult Version (BRIEF-A) as a subjective measure of executive functioning. A selection of objective cognitive tests were also used to measure a series of executive functions and to identify symptoms of depression and anxiety.

RESULTS

Patients with fibromyalgia perceived greater difficulties than the control group on all of the BRIEF-A scales. However, after adjustments were made for depression and anxiety the only differences that remained were those associated with the working memory scale and the Metacognition and Global Executive Composite index. In the case of the objective cognitive tests, a significantly worse overall performance was evidenced for the fibromyalgia patients. However, this also disappeared when adjustments were made for depression and anxiety. After this adjustment, fibromyalgia patients only performed significantly worse for the interference effect in the Stroop Test. Although there were no significant associations between most of the objective cognitive tests and the BRIEF-A scales, depression and anxiety exhibited strong associations with almost all of the BRIEF-A scales and with several of the objective cognitive tests.

CONCLUSIONS

Patients with fibromyalgia showed executive dysfunction in subjective and objective measures, although most of this impairment was associated with mood disturbances. Exceptions to this general rule were observed in the impairment of working memory evidenced on the BRIEF-A scale and the inhibition impairment exhibited by the interference effect from the Stroop Test. The two types of measurement provide different yet complementary information.

Functional network centrality in obesity: A resting-state and task fMRI study

Obesity is associated with structural and functional alterations in brain areas that are often functionally distinct and anatomically distant. This suggests that obesity is associated with differences in functional connectivity of regions distributed across the brain. However, studies addressing whole brain functional connectivity in obesity remain scarce. Here, we compared voxel-wise degree centrality and eigenvector centrality between participants with obesity (n=20) and normal-weight controls (n=21). We analyzed resting state and task-related fMRI data acquired from the same individuals. Relative to normal-weight controls, participants with obesity exhibited reduced degree centrality in the right middle frontal gyrus in the resting-state condition. During the task fMRI condition, obese participants exhibited less degree centrality in the left middle frontal gyrus and the lateral occipital cortex along with reduced eigenvector centrality in the lateral occipital cortex and occipital pole. Our results highlight the central role of the middle frontal gyrus in the pathophysiology of obesity, a structure involved in several brain circuits signaling attention, executive functions and motor functions. Additionally, our analysis suggests the existence of task-dependent reduced centrality in occipital areas; regions with a role in perceptual processes and that are profoundly modulated by attention.

Reward processing in obesity, substance addiction and non-substance addiction

Similarities and differences between obesity and addiction are a prominent topic of ongoing research. We conducted an activation likelihood estimation meta-analysis on 87 studies in order to map the functional magnetic resonance imaging (fMRI) response to reward in participants with obesity, substance addiction and non-substance (or behavioural) addiction, and to identify commonalities and differences between them. Our study confirms the existence of alterations during reward processing in obesity, non-substance addiction and substance addiction. Specifically, participants with obesity or with addictions differed from controls in several brain regions including prefrontal areas, subcortical structures and sensory areas. Additionally, participants with obesity and substance addictions exhibited similar blood-oxygen-level-dependent fMRI hyperactivity in the amygdala and striatum when processing either general rewarding stimuli or the problematic stimuli (food and drug-related stimuli, respectively). We propose that these similarities may be associated with an enhanced focus on reward--especially with regard to food or drug-related stimuli--in obesity and substance addiction. Ultimately, this enhancement of reward processes may facilitate the presence of compulsive-like behaviour in some individuals or under some specific circumstances. We hope that increasing knowledge about the neurobehavioural correlates of obesity and addictions will lead to practical strategies that target the high prevalence of these central public health challenges.

Classification models for neurocognitive impairment in HIV infection based on demographic and clinical variables

Objective

We used demographic and clinical data to design practical classification models for prediction of neurocognitive impairment (NCI) in people with HIV infection.

Methods

The study population comprised 331 HIV-infected patients with available demographic, clinical, and neurocognitive data collected using a comprehensive battery of neuropsychological tests. Classification and regression trees (CART) were developed to obtain detailed and reliable models to predict NCI. Following a practical clinical approach, NCI was considered the main variable for study outcomes, and analyses were performed separately in treatment-naïve and treatment-experienced patients.

Results

The study sample comprised 52 treatment-naïve and 279 experienced patients. In the first group, the variables identified as better predictors of NCI were CD4 cell count and age (correct classification [CC]: 79.6%, 3 final nodes). In treatment-experienced patients, the variables most closely related to NCI were years of education, nadir CD4 cell count, central nervous system penetration-effectiveness score, age, employment status, and confounding comorbidities (CC: 82.1%, 7 final nodes). In patients with an undetectable viral load and no comorbidities, we obtained a fairly accurate model in which the main variables were nadir CD4 cell count, current CD4 cell count, time on current treatment, and past highest viral load (CC: 88%, 6 final nodes).

Conclusion

Practical classification models to predict NCI in HIV infection can be obtained using demographic and clinical variables. An approach based on CART analyses may facilitate screening for HIV-associated neurocognitive disorders and complement clinical information about risk and protective factors for NCI in HIV-infected patients.

The interaction effect between BDNF val66met polymorphism and obesity on executive functions and frontal structure

The prevalence of obesity is increasing worldwide. Previous research has shown a relationship between obesity and both executive functioning alterations and frontal cortex volume reductions. The Brain Derived Neurotrophic Factor val66met polymorphism, involved in eating behavior, has also been associated with executive functions and prefrontal cortex volume, but to date it has not been studied in relation to obesity. Our aim is to elucidate whether the interaction between the Brain Derived Neurotrophic Factor val66met polymorphism and obesity status influences executive performance and frontal-subcortical brain structure. Sixty-one volunteers, 34 obese and 27 controls, age range 12-40, participated in the study. Participants were assigned to one of two genotype groups (met allele carriers, n = 16, or non-carriers, n = 45). Neuropsychological assessment comprised the Trail Making Test, the Stroop Test and the Wisconsin Card Sorting Test, all tasks that require response inhibition and cognitive flexibility. Subjects underwent magnetic resonance imaging in a Siemens TIM TRIO 3T scanner and images were analyzed using the FreeSurfer software. Analyses of covariance controlling for age and intelligence showed an effect of the obesity-by-genotype interaction on perseverative responses on the Wisconsin Card Sorting Test as well as on precentral and caudal middle frontal cortical thickness: obese met allele carriers showed more perseverations on the Wisconsin Card Sorting Test and lower frontal thickness than obese non-carriers and controls. In conclusion, the Brain Derived Neurotrophic Factor may play an important role in executive functioning and frontal brain structure in obesity.

Computer-assisted cognitive remediation therapy: cognition, self-esteem and quality of life in schizophrenia

BACKGROUND

Quality of life (QoL) is an important outcome in the treatment of schizophrenia. Cognitive deficits have an impact on functional outcomes. Cognitive remediation therapy is emerging as a psychological intervention that targets cognitive impairment, but the effect of computer-assisted cognitive remediation on neuropsychology and social functioning and wellbeing remains unclear. The aim of the current study is to investigate the neurocognitive outcomes of computer-assisted cognitive remediation (CACR) therapy in a sample of schizophrenia patients, and to measure the quality of life and self-esteem as secondary outcomes.

METHODS

Sixty-seven people with schizophrenia were randomly assigned to computer-assisted cognitive remediation or an active control condition. The main outcomes were neuropsychological measures and secondary outcomes (self-esteem and quality of life). Measurements were recorded at baseline and post-treatment.

RESULTS

The CACR therapy group improved in speed of processing, working memory and reasoning and problem-solving cognitive domains. QoL and self-esteem measures also showed significant improvements over time in this group.

CONCLUSIONS

Computer-assisted cognitive remediation therapy for people with schizophrenia achieved improvements in neuropsychological performance and in QoL and self-esteem measurements.

[Cognitive dysfunction in fibromyalgia]

INTRODUCTION

People with a fibromyalgia diagnosis complain of having very poor cognitive functioning. In recent years, there has been an increasing interest to investigate which cognitive impairment is present in this disease.

AIM

To review the published research on fibromyalgia and cognitive dysfunction.

DEVELOPMENT

A literature search was performed with a time interval from 1995 to 2012. Search terms included the keywords 'fibromyalgia' and 'cognition', 'attention', 'memory', 'language', 'perception', 'executive functions' and 'dis-executive syndrome'. 64 records were selected after applying inclusion criteria.

CONCLUSIONS

Studies that have examined cognitive function in people diagnosed with fibromyalgia have been few and mostly with small samples. Deficits have been identified mainly in working memory and complex attentional functions, where the distraction factor has an important significance. Impairment has also been identified in long-term memory and executive functions. There is consensus among the studies in which the degree of pain is directly related to the level of cognitive dysfunction, while no full consensus to explain the influence of depression and anxiety on cognitive functioning in these patients.

Efficacy of an adjunctive computer-based cognitive training program in amnestic mild cognitive impairment and Alzheimer's disease: a single-blind, randomized clinical trial

OBJECTIVE

This study evaluates the efficacy at 12 months of a computer-based cognitive training (CBCT) program, adjunctive to traditional cognitive training (TCT), on the basis of pen-and-paper exercises.

METHODS

Sixty patients with multi-domain mild cognitive impairment and mild Alzheimer's disease who were already receiving cognitive training, recruited from a day hospital, were assigned into two groups following a simple randomization procedure (computerized random numbers): (i) a group that received CBCT during 3 months and TCT (CBCT + TCT), n = 37, and (ii) a group that received only TCT, n = 23. Patients were assessed at baseline and after 3 and 12 months of treatment by a neuropsychologist blinded to group assignment, with a neuropsychological battery (primary outcomes) and measures of decision making, memory complaints, and emotional disturbances.

RESULTS

With the use of repeated-measures analyses of covariance, the CBCT + TCT group showed less anxiety symptoms (F = 5.13, p = 0.03, d = 1.12) and less disadvantageous choices (F = 4.70, p = 0.04, d = 0.89) in decision making than the TCT group at 12 months. No significant improvement or worsening was observed in the other measures examined. However, positive effect sizes favoring the CBCT + TCT group were observed in all variables.

CONCLUSIONS

The addition of a CBCT program was effective in anxiety and decision making but had no significant effects on outcomes in basic cognitive functions in patients who were already receiving cognitive training, possibly due to a ceiling effect. Future studies should compare the efficacy of CBCT with TCT in naïve patients.

The effect of carotid occlusion in cognition before endarterectomy

The role of carotid stenosis on cognition remains to be determined. To study whether people with stenosis of the carotid artery have increased cognitive impairments, we studied 53 patients with moderate or severe carotid stenosis (with no symptoms of stroke or dementia) and 53 controls. We describe which cognitive functions were impaired in the patients and whether there were differences based on the side, the severity of the stenosis or the presence of neurological symptoms. Using the Repeatable Battery for the Assessment of Neuropsychological Status, we found that the patients with carotid stenosis had lower cognitive performances in attention, verbal memory, visuospatial capacity and verbal fluency. Patients with lesser degrees of stenosis than healthy control patients had better scores in learning and memory. The results from this study suggest that patients with severe carotid stenosis have a lower cognitive status than healthy control patients, which is associated with the degree of total carotid stenosis.

Alterations of the salience network in obesity: a resting-state fMRI study

Obesity is a major health problem in modern societies. It has been related to abnormal functional organization of brain networks believed to process homeostatic (internal) and/or salience (external) information. This study used resting-state functional magnetic resonance imaging analysis to delineate possible functional changes in brain networks related to obesity. A group of 18 healthy adult participants with obesity were compared with a group of 16 lean participants while performing a resting-state task, with the data being evaluated by independent component analysis. Participants also completed a neuropsychological assessment. Results showed that the functional connectivity strength of the putamen nucleus in the salience network was increased in the obese group. We speculate that this abnormal activation may contribute to overeating through an imbalance between autonomic processing and reward processing of food stimuli. A correlation was also observed in obesity between activation of the putamen nucleus in the salience network and mental slowness, which is consistent with the notion that basal ganglia circuits modulate rapid processing of information.