Attention bias and novel object test in rams (Ovis aries) under intensive farming

Affective states are long lasting mood states resulting from an accumulation of experiences. The knowledge of the affective state of animals can significantly help maintain and/or increase animal welfare. The aim of the study was to recognize the affective state of 13 adult rams reared under an intensive system and to further associate their affective state with hierarchy, sociability order and maintenance and social behaviour. The affective state was estimated by exposing them to an attention bias test and two novel object tests. Individuals with negative affective states performed reduced head hanging (p = 0.014), reduced agonistic behaviour (p = 0.033), increased social proximity (p = 0.009) and received less affiliative behaviours (p = 0.006). The study estimated the affective state of the rams and indicated easily recognizable maintenance and social behaviours correlated with negative affective state. Such behaviours could increase the awareness of the animals' welfare and thus improve management practices.

Comparing the association between heavy metals and cognitive status and depression in miners and non-miners: A study from southeast of Iran

Heavy metal toxicity is a major public health crisis worldwide, especially in mining environments. The association between chronic heavy metals exposure and cognitive impairment has not been studied broadly in adults and mining fields. This study aimed to compare the association between arsenic (As), lead (Pb), and copper (Cu) concentration in blood and cognitive status and depression in copper miners and non-miners. Participants were selected from the Rafsanjan cohort study (RCS) as non-miners and miners from Sarcheshmeh Copper Complex. For evaluation of cognitive performance and creativity, comprehensive neurological tests were performed as follows: Mini-Mental Status Examination (MMSE), Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Psychomotor Vigilance Task (PVT), creativity tests including remote association task (RAT) and alternative uses task (AUT). Beck Depression Inventory-II was used to evaluate depression. Standard laboratory tests were also performed. Atomic absorption spectrophotometry was used to estimate the blood's concentration of As, Pb and Cu. We observed a significant difference between arsenic, lead, copper, and depression scores (all P < 0.001) in the two groups (miners and non-miners). Miners had a better performance in cognitive fields except in MMSE and PVT tests. Linear regression analyses showed that the lead had a negative association with the PVT test and depression score. The results suggest that the development of depression, cognitive impairments, and other health problems is possible in chronic heavy metal exposure, especially lead (Pb). Confirmation of our claim requires further study in the coming years.

The Utility of Visual and Spatial Perception Tests in Alzheimer's Disease: A Systematic Review

INTRODUCTION

Visual and spatial perception (VSP) are cognitive domains frequently assessed in the screening and neuropsychological assessment of dementia. Evidence suggests that VSP impairment is common in the early stages of Alzheimer's disease (AD). Despite this evidence, the ability of VSP tests to discriminate between healthy older adults and people with AD remains mixed. The purpose of this literature review was to employ a systematic search strategy to identify empirical evidence supporting the diagnostic utility of VSP tests which may be used in the screening and diagnosis of AD.

METHODS

Specified criteria were used to perform a systematic literature search of the PsycINFO and PubMed databases with no date restrictions. Relevant data from the selected studies were extracted, and a published appraisal tool (the Quality Assessment of Diagnostic Accuracy Studies-2) was used to evaluate methodological quality.

RESULTS

Of the 144 articles returned, six studies and 11 VSP tests met review inclusion criteria. Four tests demonstrated both sensitivity and specificity values above 80%. A computerised 3D Visual Task demonstrated the highest sensitivity and specificity values (90% and 95%, respectively). The quality of the identified studies was considered to be satisfactory. Identified limitations and the implications of issues relating to study methodology are discussed, and recommendations for future research are suggested.

CONCLUSION

The evidence from this review suggests that certain tests of VSP may be a useful addition to the routine screening of AD.

Psychometric evaluation of the computerized battery for neuropsychological evaluation of children (BENCI) among school aged children in the context of HIV in an urban Kenyan setting

INTRODUCTION

Culturally validated neurocognitive measures for children in Low- and Middle-Income Countries are important in the timely and correct identification of neurocognitive impairments. Such measures can inform development of interventions for children exposed to additional vulnerabilities like HIV infection. The Battery for Neuropsychological Evaluation of Children (BENCI) is an openly available, computerized neuropsychological battery specifically developed to evaluate neurocognitive impairment. This study adapted the BENCI and evaluated its reliability and validity in Kenya.

METHODOLOGY

The BENCI was adapted using translation and back-translation from Spanish to English. The psychometric properties were evaluated in a case-control study of 328 children (aged 6 - 14 years) living with HIV and 260 children not living with HIV in Kenya. We assessed reliability, factor structure, and measurement invariance with respect to HIV. Additionally, we examined convergent validity of the BENCI using tests from the Kilifi Toolkit.

RESULTS

Internal consistencies (0.49 < α < 0.97) and test-retest reliabilities (-.34 to .81) were sufficient-to-good for most of the subtests. Convergent validity was supported by significant correlations between the BENCI's Verbal memory and Kilifi's Verbal List Learning (r = .41), the BENCI's Visual memory and Kilifi's Verbal List Learning (r = .32) and the BENCI's Planning total time test and Kilifi's Tower Test (r = -.21) and the BENCI's Abstract Reasoning test and Kilifi's Raven's Progressive Matrix (r = .21). The BENCI subtests highlighted meaningful differences between children living with HIV and those not living with HIV. After some minor adaptions, a confirmatory four-factor model consisting of flexibility, fluency, reasoning and working memory fitted well (χ² = 135.57, DF = 51, N = 604, p < .001, RMSEA = .052, CFI = .944, TLI = .914) and was partially scalar invariant between HIV positive and negative groups.

CONCLUSION

The English version of the BENCI formally translated for use in Kenya can be further adapted and integrated in clinical and research settings as a valid and reliable cognitive test battery.

Evaluating the feasibility of cognitive impairment detection in Alzheimer's disease screening using a computerized visual dynamic test

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease without known cure. However, early medical treatment can help control its progression and postpone intellectual decay. Since AD is preceded by a period of cognitive deterioration, the effective assessment of cognitive capabilities is crucial to develop reliable screening procedures. For this purpose, cognitive tests are extensively used to evaluate cognitive areas such as language, attention, or memory.

METHODS

In this work, we analyzed the potential of a visual dynamics evaluation, the rapid serial visual presentation task (RSVP), for the detection of cognitive impairment in AD. We compared this evaluation with two of the most extended brief cognitive tests applied in Spain: the Clock-drawing test (CDT) and the Phototest. For this purpose, we assessed a group of patients (mild AD and mild cognitive impairment) and controls, and we evaluated the ability of the three tests for the discrimination of the two groups.

RESULTS

The preliminary results obtained suggest the RSVP performance is statistically higher for the controls than for the patients (p-value = 0.013). Furthermore, we obtained promising classification results for this test (mean accuracy of 0.91 with 95% confidence interval 0.72, 0.97).

CONCLUSIONS

Since the RSVP is a computerized, auto-scored, and potentially self-administered brief test, it could contribute to speeding-up cognitive impairment screening and to reducing the associated costs. Furthermore, this evaluation could be combined with other tests to augment the efficiency of cognitive impairment screening protocols and to potentially monitor patients under medical treatment.

Cerebrospinal Fluid Profile of Lipid Mediators in Alzheimer's Disease

Alzheimer's disease (AD) develops into dementia over a period of several years, during which subjective cognitive impairment (SCI) and mild cognitive impairment (MCI) can be used as intermediary diagnoses of increasing severity. Chronic neuroinflammation resulting from insufficient resolution is involved in the pathogenesis of AD and is associated with cognitive impairment. Specialized pro-resolving lipid mediators (LMs) that promote the resolution of inflammation may be valuable markers in AD diagnosis and as therapeutic targets. Liquid chromatography-tandem mass spectrometry was used to analyze pro-resolving and pro-inflammatory LMs in cerebrospinal fluid (CSF) from patients with cognitive impairment ranging from subjective impairment to a diagnosis of AD and correlated to cognition, CSF tau, and β-amyloid. Resolvin (Rv) D4, RvD1, neuroprotectin D1 (NPD1), maresin 1 (MaR1), and RvE4 were lower in AD and/or MCI compared to SCI. The pro-inflammatory LTB₄ and 15-HETE were higher in AD and MCI, respectively, while PGD2, PGE2, and PGF2a were decreased in AD, compared to SCI. RvD4 was also negatively correlated to AD tangle biomarkers, and positive correlations to cognitive test scores were observed for both pro-resolving LMs and their precursor fatty acids. In this exploratory study of the lipidome in CSF of AD, MCI, and SCI, the results indicate a shift in the LM profile from pro-resolving to pro-inflammatory in progression to AD, suggesting that it may be of use as a biomarker when followed by confirmation by replication studies.

Relationship between cognitive function in individuals with diabetic foot ulcer and mortality

BACKGROUND

Diabetic foot ulcer (DFU) is a common diabetes mellitus (DM) complication. Individuals with DM and a DFU achieved significantly lower scores in cognitive tests than those without a DFU. We investigated whether baseline cognitive function in individuals with a DFU is a determinant of mortality.

METHODS

A prospective study using data collected during a case-control study conducted in 2010-2012 whereby 90 participants with a DFU (mean age at baseline 58.28 ± 6.95 years, 75.6% male) took the paper and pencil and the NeuroTrax battery of cognitive tests. Depression was assessed, and the DFU status was evaluated. In 2020, information pertaining to participants' vital status (dead/alive) was collected and the relationship between baseline cognitive status and vital status was assessed.

RESULTS

During a median follow-up of 6.8 years (range 0.2-9.5), 39 participants died (43.3%). Individuals alive vs. those who had died during follow-up had a higher global cognitive score at baseline (92.16 ± 10.95 vs. 87.18 ± 12.24, p = 0.045), but increased risk was not found. Individuals who were alive vs. those who had died during follow-up had statistically significantly higher baseline executive function, reaction time and digit symbol substitution test results. However, after adjustment for glycosylated hemoglobin (HbA1c), microvascular and macrovascular complications, no relationship between cognitive tests and mortality remained significant.

CONCLUSIONS

The higher mortality rate among people with type 2 DM and a DFU was not significant after adjustment for HbA1c, micro- and macrovascular complications. There may be common pathophysiological pathways to both DM complications and cognitive impairment, which may contribute to increased mortality. Further studies are warranted.

Serum levels of olanzapine are associated with acute cognitive effects in bipolar disorder

Bipolar (BPD) patients have deficits in cognition, but there are still controversies about the effects of some medications on their cognitive performance. Here, we investigated the relationship between cognition in terms of executive functions, memory, and attention in both first-episode medication-naive BPD patients and BPD patients taking olanzapine. Forty-one healthy controls, 40 unmedicated drug-naive BPD patients, and 34 BPD patients who took only olanzapine were recruited for the study. Cognitive performance was assessed using the Flanker test, Stroop test, and Corsi-block test. Bayesian multivariate regression analysis was run considering maximum robustness to avoid bias and to predict the outcomes. Our results revealed that unmedicated medication-naive BPD patients performed worse than healthy controls and the olanzapine group in some tasks. Additionally, BPD patients who took olanzapine had better cognitive performance than healthy controls and unmedicated BPD patients. The acute cognitive effects were predicted by olanzapine dosage and serum levels (i.e., large effects). The potential pro-cognitive effects of olanzapine in BPD patients should be carefully interpreted by considering various other clinical variables. We expect that our findings will contribute to further research in this area, with the goal of helping other researchers, patients, and the population.

The effect of long-term radiofrequency exposure on cognition in human observational studies: A protocol for a systematic review

BACKGROUND

The long term effects of exposure to radiofrequency (RF) electromagnetic fields (EMF) for frequencies from 100 kHz to 300 GHz on cognitive performance are best assessed using observational studies. In recent years, the use of mobile (cell) phones has been the main source of RF EMF exposure to the brain, although other sources of exposure may be significant. Cognitive function includes various mental and psychological abilities, which can be measured in a range of domains, such as learning, memory, reasoning, problem solving, decision making and attention. Although effects on cognitive function may be most evident later in life, in the experimental setting acute and immediate effects can only be studied. Observational studies are needed when effects are observed after months or years following short or long-term exposure. The importance of the effects of exposure on children has also been recently identified.

OBJECTIVES

To assess the long-term effects of RF EMF local and whole-body exposure compared to no or a lower level of exposure on indicators of cognition, including complex attention, executive function, learning and memory, perceptual motor ability and social cognition, but excluding cognitive effects caused by neurodegenerative diseases or neurodevelopmental disorders, and to assess if there is evidence of a dose response relationship.

STUDY ELIGIBILITY AND CRITERIA

We will include observational studies that have evaluated cognitive effects of RF energy including a comparator group with a different level of exposure. Studies must report at least one validated measure of cognitive function, including global or domain specific measures, or cognitive impairment, with a minimum follow-up of 6 months. Cohort or case-control studies published in the peer review literature in any language are eligible. We will exclude cross-sectional studies and any that only report brain structure or biomarkers.

STUDY APPRAISAL AND SYNTHESIS METHOD

We will conduct searches of PubMed, Embase, PsycINFO and the EMF-Portal. At least two authors will independently screen the titles/abstracts of all records, with any conflicts resolved by a third reviewer. Full-text screening will also be conducted independently by two authors with conflicts resolved by consensus. Data will be extracted from the studies included, such as identifiers and characteristics of the study design, exposure and comparator groups, participants, outcomes assessed and results. Risk of bias will be assessed with the Office of Health Assessment and Translation (OHAT) tool. We will conduct a meta-analysis of similar studies with a random effects model in STATA or similar software, if two or more studies are available for a given exposure-outcome combination. Confidence in the body evidence will be judged using GRADE methods as adapted by OHAT for reviews of environmental exposures.

The cross-sectional association of cognition with diabetic peripheral and autonomic neuropathy-The GRADE study

BACKGROUND

Studies examining whether measures of cognition are related to the presence of diabetic peripheral neuropathy (DPN) and/or cardiovascular autonomic neuropathy (CAN) are lacking, as are data regarding factors potentially explaining such associations.

METHODS

Participants were from the Glycemia Reduction Approaches in Diabetes Study (GRADE) that examined 5047 middle-aged people with type 2 diabetes of <10 years of known duration. Verbal learning and immediate and delayed recall (memory) were assessed with the Spanish English Verbal Learning Test; frontal executive function and processing speed with the Digit Symbol Substitution Test; and ability to concentrate and organize data with word and animal fluency tests. DPN was assessed with the Michigan Neuropathy Screening Instrument and CAN by indices of heart rate variability (standard deviation of normal beat to beat variation [SDNN] and root mean square of successive differences [RMSSD]).

RESULTS

DPN was significantly inversely related to measures of immediate recall and processing speed. The percent of cognitive variation explained by DPN was small. Tests of CAN had an inconsistent or absent association with measures of cognition. Higher waist circumference and urine albumin creatinine (UACR) levels were the strongest correlates in the relationship between DPN and cognitive impairment.

CONCLUSION

DPN, but not CAN, was cross-sectionally associated with lower performance in measures of cognition in people with type 2 diabetes of <10 years of known duration. Greater waist circumference and UACR were important variables in this association. The mechanisms underlying the cross-sectional association of DPN with cognitive impairment are unknown. Clinicaltrials.gov: NCT01794143.

Detecting the Cognitive Prodrome of Dementia in Parkinson's Disease

BACKGROUND

More than 75% of Parkinson's disease (PD) patients will develop dementia. Previous studies on the cognitive predictors of dementia in PD had some methodological limitations and the cognitive tests identified as good predictors vary greatly.

OBJECTIVE

This prospective cohort study aims to identify the optimal cognitive predictors of dementia in PD using complementary statistical methods.

METHODS

Eighty PD patients without dementia underwent polysomnographic recording, a neurological examination, and a complete neuropsychological assessment at baseline. They were then followed for a mean of 4.3 years. Baseline group comparisons and survival analyses were used to identify optimal cognitive predictors. Moreover, patients who developed dementia were pair-matched at baseline according to age, sex, and education to healthy controls (2 : 1), and receiver operating characteristic curves were calculated for cognitive tests.

RESULTS

At follow-up, 23 patients (29%) developed dementia. PD patients who developed dementia had poorer baseline performance and a higher proportion of clinically impaired performance on several cognitive tests. Impaired baseline performance on the Block Design subtest was the best independent predictor of dementia (HR = 8). Moreover, the Trail Making Test part B (time) and Verbal Fluency (semantic) had the best psychometric properties (area under the curve >0.90) for identifying PD patients at risk of dementia.

CONCLUSION

The present study identified three cognitive tests as the most accurate to detect individuals with PD at high risk of developing dementia.

Sex, Race, and Age Differences in Prevalence of Dementia in Medicare Claims and Survey Data

OBJECTIVES

This study provides the first comparison of trends in dementia prevalence in the U.S. population using 3 different dementia ascertainments/data sources: neuropsychological assessment, cognitive tests, and diagnosis codes from Medicare claims.

METHODS

We used data from the nationally representative Health and Retirement Study and Aging, Demographics, and Memory Study, and a 20% random sample of Medicare beneficiaries. We compared dementia prevalence across the 3 sources by race, gender, and age. We estimated trends in dementia prevalence from 2006 to 2013 based on cognitive tests and diagnosis codes utilizing logistic regression.

RESULTS

Dementia prevalence among older adults aged 70 and older in 2004 was 16.6% (neuropsychological assessment), 15.8% (cognitive tests), and 12.2% (diagnosis codes). The difference between dementia prevalence based on cognitive tests and diagnosis codes diminished in 2012 (12.4% and 12.9%, respectively), driven by decreasing rates of cognitive test-based and increasing diagnosis codes-based dementia prevalence. This difference in dementia prevalence between the 2 sources by sex and for age groups 75-79 and 90 and older vanished over time. However, there remained substantial differences across measures in dementia prevalence among blacks and Hispanics (10.9 and 9.8 percentage points, respectively) in 2012.

DISCUSSION

Our results imply that ascertainment of dementia through diagnosis may be improving over time, but gaps across measures among racial/ethnic minorities highlight the need for improved measurement of dementia prevalence in these populations.

Cystic fibrosis-related diabetes (CFRD) and cognitive function in adults with cystic fibrosis

BACKGROUND

Being able to function cognitively is imperative for successful achievement in school, working life, and disease self-management. Diabetes is known to cause changes in brain structure and long-term cognitive dysfunction. This work investigated cystic fibrosis-related diabetes (CFRD) as a mechanism for cognitive impairment in people with CF. It was hypothesised that cognition would be poorer in adults with CFRD than in those with CF without diabetes (CFND) or in healthy controls.

METHODS

Cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery which provides a comprehensive cognitive assessment with tests mapping onto specific brain regions. Demographic, clinical and self-reported health data were documented for all participants. CF specific clinical variables were recorded for the two CF groups.

RESULTS

Ninety-eight people with CF (49CFRD,49CFND) and 49 healthy controls were recruited. People with CF demonstrated deficits in aspects of verbal and spatial memory, processing speed and cognitive flexibility compared with healthy controls, with all areas of the brain implicated. Those with CFRD had additional difficulties with higher-level processes known collectively as 'executive function', which demand greater cognitive load and recruit the prefrontal cortex. Compared with healthy controls, those with CFND and CFRD had an estimated 20% and up to 40% reduction in processing speed respectively.

CONCLUSION

Managing CF requires higher order executive function. Impairments may be sufficient to interfere with self-care and the ability to perform everyday tasks efficiently. At which point in the CF disease trajectory these difficulties begin, and what may attenuate them, has yet to be determined.

Relationships between motor scores and cognitive functioning in FMR1 female premutation X carriers indicate early involvement of cerebello-cerebral pathways

BACKGROUND

Smaller expansions of CGG trinucleotide repeats in the FMR1 X-linked gene termed 'premutation' lead to a neurodegenerative disorder: Fragile X Associated Tremor/Ataxia Syndrome (FXTAS) in nearly half of aged carrier males, and 8-16% females. Core features include intention tremor, ataxia, and cognitive decline, and white matter lesions especially in cerebellar and periventricular locations. A 'toxic' role of elevated and expanded FMR1 mRNA has been linked to the pathogenesis of this disorder. The emerging issue concerns the trajectory of the neurodegenerative changes: is the pathogenetic effect confined to overt clinical manifestations? Here we explore the relationships between motor and cognitive scale scores in a sample of 57 asymptomatic adult female premutation carriers of broad age range.

METHODS

Three motor scale scores (ICARS-for tremor/ataxia, UPDRS-for parkinsonism, and Clinical Tremor) were related to 11 cognitive tests using Spearman's rank correlations. Robust regression, applied in relationships between all phenotypic measures, and genetic molecular and demographic data, identified age and educational levels as common correlates of these measures, which were then incorporated as confounders in correlation analysis.

RESULTS

Cognitive tests demonstrating significant correlations with motor scores were those assessing non-verbal reasoning on Matrix Reasoning (p-values from 0.006 to 0.011), and sequencing and alteration on Trails-B (p-values from 0.008 to 0.001). Those showing significant correlations with two motor scores-ICARS and Clinical Tremor- were psychomotor speed on Symbol Digit Modalities (p-values from 0.014 to 0.02) and working memory on Digit Span Backwards (p-values from 0.024 to 0.011).

CONCLUSIONS

Subtle motor impairments correlating with cognitive, particularly executive, deficits may occur in female premutation carriers not meeting diagnostic criteria for FXTAS. This pattern of cognitive deficits is consistent with those seen in other cerebellar disorders. Our results provide evidence that more than one category of clinical manifestation reflecting cerebellar changes - motor and cognitive - may be simultaneously affected by premutation carriage across a broad age range in asymptomatic carriers.

Deep recurrent model for individualized prediction of Alzheimer's disease progression

Alzheimer's disease (AD) is known as one of the major causes of dementia and is characterized by slow progression over several years, with no treatments or available medicines. In this regard, there have been efforts to identify the risk of developing AD in its earliest time. While many of the previous works considered cross-sectional analysis, more recent studies have focused on the diagnosis and prognosis of AD with longitudinal or time series data in a way of disease progression modeling. Under the same problem settings, in this work, we propose a novel computational framework that can predict the phenotypic measurements of MRI biomarkers and trajectories of clinical status along with cognitive scores at multiple future time points. However, in handling time series data, it generally faces many unexpected missing observations. In regard to such an unfavorable situation, we define a secondary problem of estimating those missing values and tackle it in a systematic way by taking account of temporal and multivariate relations inherent in time series data. Concretely, we propose a deep recurrent network that jointly tackles the four problems of (i) missing value imputation, (ii) phenotypic measurements forecasting, (iii) trajectory estimation of a cognitive score, and (iv) clinical status prediction of a subject based on his/her longitudinal imaging biomarkers. Notably, the learnable parameters of all the modules in our predictive models are trained in an end-to-end manner by taking the morphological features and cognitive scores as input, with our circumspectly defined loss function. In our experiments over The Alzheimers Disease Prediction Of Longitudinal Evolution (TADPOLE) challenge cohort, we measured performance for various metrics and compared our method to competing methods in the literature. Exhaustive analyses and ablation studies were also conducted to better confirm the effectiveness of our method.

The role of neuropsychological assessment in adults with attention deficit/hyperactivity disorders

Attention-Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity and/or impulsivity. While ADHD was initially recognized as a childhood syndrome, scientific evidence accumulated to indicate that a significant proportion of ADHD children continue to experience symptoms of ADHD in adulthood. Moreover, the question of ADHD diagnosis can arise in adult patients who were not diagnosed in childhood. Currently, the diagnosis of ADHD in adulthood is based on the revised criteria described for children. However, their application for adults may be difficult for many reasons including compensation and comorbid disorders. To date, no clinical, neuropsychological, biological or imaging marker is available for the diagnosis of ADHD. Considering that ADHD is based on a neuropsychological model, in this article we will examine the usefulness of neuropsychological testing in the diagnosis in adults. We will first present diagnostic criteria of ADHD and the limits of their application in adults. We will then detail the neuropsychological data available in adult ADHD and the French and international clinical recommendations for neuropsychological assessment. Finally, we will explore the predictive value of neuropsychological scores in the diagnosis of ADHD and discuss key methodological points and perspectives for clinical research.

Iranian Brain Imaging Database: A Neuropsychiatric Database of Healthy Brain

INTRODUCTION

The Iranian Brain Imaging Database (IBID) was initiated in 2017, with 5 major goals: provide researchers easy access to a neuroimaging database, provide normative quantitative measures of the brain for clinical research purposes, study the aging profile of the brain, examine the association of brain structure and function, and join the ENIGMA consortium. Many prestigious databases with similar goals are available. However, they were not done on an Iranian population, and the battery of their tests (e.g. cognitive tests) is selected based on their specific questions and needs.

METHODS

The IBID will include 300 participants (50% female) in the age range of 20 to 70 years old, with an equal number of participants (#60) in each age decade. It comprises a battery of cognitive, lifestyle, medical, and mental health tests, in addition to several Magnetic Resonance Imaging (MRI) protocols. Each participant completes the assessments on two referral days.

RESULTS

The study currently has a cross-sectional design, but longitudinal assessments are considered for the future phases of the study. Here, details of the methodology and the initial results of assessing the first 152 participants of the study are provided.

CONCLUSION

IBID is established to enable research into human brain function, to aid clinicians in disease diagnosis research, and also to unite the Iranian researchers with interests in the brain.

Neuropsychological Equivalence of the Clinical Diagnosis of Mild Cognitive Impairment in the National Alzheimer's Coordinating Center Uniform Data Set and Alzheimer's Disease Neuroimaging Initiative

INTRODUCTION

Our understanding of Alzheimer's disease may be improved by harmonizing data from large cohort studies of older adults. Differences in the way clinical conditions, like mild cognitive impairment (MCI), are diagnosed may lead to variability among participants that share the same diagnostic label. This variability presents a challenge for cohort harmonization and may lead to inconsistency in research findings. Little research to date has explored the equivalence of the diagnostic label of MCI across 2 of the largest and most influential cohort studies in the USA: the National Alzheimer's Coordinating Center (NACC) and the Alzheimer's Disease Neuroimaging Initiative (ADNI).

METHODS

Participants with MCI due to presumed Alzheimer's disease from the NACC Uniform Data Set (n = 789) and ADNI (n = 131) were compared on demographic, psychological, and functional variables, as well as on an abbreviated neuropsychological battery common to the 2 data sets.

RESULTS

Though similar in terms of age, education, and functional status, the NACC sample was more diverse (17.4% non-White participants vs. 7.6% in ADNI; χ2 = 7.923, p = 0.005) and tended to perform worse on some cognitive tests. In particular, participants diagnosed with MCI in NACC were more likely to have clinically significant impairments on language measures (26.36-31.18%) than MCI participants in ADNI (16.03-19.85%).

DISCUSSION

The current findings suggest important differences in cognitive performances between 2 large MCI cohorts, likely reflective of differences in diagnostic criteria used in these 2 studies, as well as differences in sample compositions. Such diagnostic heterogeneity may make harmonizing data across these cohorts challenging. However, application of shared psychometric criteria across studies may lead to closer equivalence of MCI groups. Such approaches could pave the way for cohort harmonization and enable "big data" analytic approaches to understanding Alzhei-mer's to be developed.

Impulsivity traits and neurocognitive mechanisms conferring vulnerability to substance use disorders

Impulsivity - the tendency to act without sufficient consideration of potential consequences in pursuit of short-term rewards - is a vulnerability marker for substance use disorders (SUD). Since impulsivity is a multifaceted construct, which encompasses trait-related characteristics and neurocognitive mechanisms, it is important to ascertain which of these aspects are significant contributors to SUD susceptibility. In this review, we discuss how different trait facets, cognitive processes and neuroimaging indices underpinning impulsivity contribute to the vulnerability to SUD. We reviewed studies that applied three different approaches that can shed light on the role of impulsivity as a precursor of substance use related problems (versus a consequence of drug effects): (1) longitudinal studies, (2) endophenotype studies including non-affected relatives of people with SUD, and (3) clinical reference groups-based comparisons, i.e., between substance use and behavioural addictive disorders. We found that, across different methodologies, the traits of non-planning impulsivity and affect-based impulsivity and the cognitive processes involved in reward-related valuation are consistent predictors of SUD vulnerability. These aspects are associated with the structure and function of the medial orbitofrontal-striatal system and hyperexcitability of dopamine receptors in this network. The field still needs more theory-driven, comprehensive studies that simultaneously assess the different aspects of impulsivity in relation to harmonised SUD-related outcomes. Furthermore, future studies should investigate the impact of impulsivity-related vulnerabilities on novel patterns of substance use such as new tobacco and cannabinoid products, and the moderating impact of changes in social norms and lifestyles on the link between impulsivity and SUD. This article is part of the special issue on 'Vulnerabilities to Substance Abuse'.

Leukocyte Telomere Length Is Unrelated to Cognitive Performance Among Non-Demented and Demented Persons: An Examination of Long Life Family Study Participants

OBJECTIVE

Leukocyte telomere length (LTL) is a widely hypothesized biomarker of biological aging. Persons with shorter LTL may have a greater likelihood of developing dementia. We investigate whether LTL is associated with cognitive function, differently for individuals without cognitive impairment versus individuals with dementia or incipient dementia.

METHOD

Enrolled subjects belong to the Long Life Family Study (LLFS), a multi-generational cohort study, where enrollment was predicated upon exceptional family longevity. Included subjects had valid cognitive and telomere data at baseline. Exclusion criteria were age ≤ 60 years, outlying LTL, and missing sociodemographic/clinical information. Analyses were performed using linear regression with generalized estimating equations, adjusting for sex, age, education, country, generation, and lymphocyte percentage.

RESULTS

Older age and male gender were associated with shorter LTL, and LTL was significantly longer in family members than spouse controls (p < 0.005). LTL was not associated with working or episodic memory, semantic processing, and information processing speed for 1613 cognitively unimpaired individuals as well as 597 individuals with dementia or incipient dementia (p < 0.005), who scored significantly lower on all cognitive domains (p < 0.005).

CONCLUSIONS

Within this unique LLFS cohort, a group of families assembled on the basis of exceptional survival, LTL is unrelated to cognitive ability for individuals with and without cognitive impairment. LTL does not change in the context of degenerative disease for these individuals who are biologically younger than the general population.

Patterns of Cognitive Test Scores and Symptom Complaints in Persons with TBI Who Failed Performance Validity Testing

OBJECTIVE

To determine clinically meaningful subgroups of persons with traumatic brain injury (TBI) who have failed performance validity testing.

METHOD

Study participants were selected from a cohort of 674 participants with definitive medical evidence of TBI. Participants were those who failed performance validity testing (the Word Memory Test, using the standard cutoffs). Participants were administered cognitive tests and self-report questionnaires. Test and questionnaire results were summarized as 12 dimension scores. Cluster analysis using the k-means method was performed.

RESULTS

Cluster analysis for the 143 retained participants indicated three subgroups. These subgroups differed on patterns of scores. Subgroup 1 was impaired for memory and had no excessive complaints. Subgroup 2 had impaired memory and processing speed as well as concern regarding cognition function. Subgroup 3 showed impairment on all cognitive tests and excess complaints in multiple areas.

CONCLUSIONS

These results provide a preliminary basis for improved understanding of poor performance validity.

The interactive effects of test-retest and methylphenidate administration on cognitive performance in youth with ADHD: A double-blind placebo-controlled crossover study

Studies have shown that Methylphenidate (MPH) affects cognitive performance on the neuropsychological tests and clinical symptoms of individuals diagnosed with attention deficit/hyperactivity disorder (ADHD). This study investigated the acute effects of MPH on neuropsychological tests to explore the interaction between MPH and test-retest effects. Twenty youths with ADHD were tested before and after MPH intake in a double-blind placebo-controlled crossover design and compared to twenty matched controls. Participants were tested on a range of standardized tasks including sustained attention to response, N-Back, and Word/Color Stroop. Identical tasks were administered twice each testing day, before and 1 hour after MPH/Placebo administration. Healthy controls were tested similarly with no intervention. Decreases in response time (RT) variability across tasks and in commission errors were found in ADHD after MPH. Conversely, a significant increase in RT variability and increase in omission errors were observed after the placebo. In the control group, RT variability and omission errors increased whereas commission errors decreased, suggesting fatigue and practice effects, respectively. Test-retest reliability was higher in controls than ADHD. It is suggested that cognitive tests are sensitive objective measures for the assessment of responses to MPH in ADHD but are also affected by repetition and fatigue.

The correlation of everyday cognition test scores and the progression of Alzheimer's disease: a data analytics study

The process of diagnosing dementia conditions, especially Alzheimer's disease, and the cognitive tests that are involved in this process, are important areas of study. Everyday Cognition (ECog) is one test that can be used as part of Alzheimer's disease diagnosis to measure cognitive decline in different areas. In this study, we investigate two versions of the ECog test: the study partner reported version (ECogSP), and the patient reported version (ECogPT). We compare these, using statistical analysis and machine learning techniques, to create classification models to demonstrate the progression in ECog scores over time by using the Alzheimer's Disease Neuroimaging Initiative longitudinal data repository (ADNI); participants are classed with having normal cognition, mild cognitive impairment, or Alzheimer's disease. We found that participants who are diagnosed with Alzheimer's disease at baseline, or during a subsequent visit, tend to self-report consistent ECogPT scores over time indicating no change in cognitive ability. However, study partners tend to report higher and increasing ECogSP scores on behalf of participants in the same diagnosis category; this would indicate a degradation in the participant's cognitive ability over time, consistent with the progress of Alzheimer's disease.

Exploring eye movements of Parkinson's disease patients performing the Judgement of line orientation test

INTRODUCTION

Parkinson's disease (PD) patients are reported to score significantly lower on the Judgement of Line Orientation (JLO) test compared with controls. The traditional method of scoring JLO ignores potentially interesting information on the mechanism of errors made.

AIM

The aim of the current study was to analyse the performance of PD patients on the JLO while monitoring eye movements. Employing eye tracking methods while PD participants attempt JLO items may prove valuable in further characterising error-patterns.

METHODS

We recruited three groups, each comprising 16 participants: PD participants with normal cognition (PD-N), PD participants with mild cognitive impairment (PD-MCI) and matched controls.

RESULTS

The mean correct response rates were high: 93% (±6) for controls, 88% (±12) for PD-N and 87% (±11) for PD-MCI; the difference did not reach statistical significance (p = 0.21). Participants made more errors as they progressed from easy to harder item (r = 0.7; p = 0.02). Using the Ska classification, error types QO1 and QO3 were by far and away the most common. The mean amplitudes of saccadic eye movements were 5.9° (±0.9) for controls, 5.7° (±1.1) for PD-N, and 5.5° (±1.0) for PD-MCI. The differences among the three groups did not reach statistical significance (p = 0.64). As a whole, participant fixation patterns were similar throughout the JLO task. For the reference lines, most fixations were made on the distal ends. Fixations on the test lines, on the other hand, appeared to vary among trials, dependent on whether the response was correct or incorrect.

CONCLUSIONS

There were few differences among the study groups in test performance-eye movement associations. However, we gained important insights into oculomotor behaviour during JLO test completion in both healthy controls and PD patients which could reflect the underlying disease state as we hypothesised.

Cognitive deficits in methamphetamine addiction: Independent contributions of dependence and intelligence

BACKGROUND

Methamphetamine's effects on brain function have been associated with cognitive deficits, which have a negative impact on clinical outcomes. However, it remains unclear if cognitive deficits relate to methamphetamine dependence (potentially amenable to abstinence and retraining) or background characteristics, mental health and other drug use. We tested the association between methamphetamine dependence and cognitive performance, while factoring in the impact of background characteristics, depressive symptoms and tobacco, alcohol and cannabis use.

METHOD

The sample comprised 108 treatment-seeking participants who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV TR) criteria for methamphetamine dependence and 50 socio-demographically matched controls. We administered a comprehensive neuropsychological test battery (delay discounting, decision making, disinhibition, episodic and working memory) and examined cognitive deficits in methamphetamine users after taking into account socio-demographic characteristics, tobacco, alcohol and cannabis use, and depressive symptoms.

RESULTS

Hierarchical multiple regression analyses showed that methamphetamine dependence was associated with poorer performance in decision-making and disinhibition over and above other predictors, while IQ better explained performance in episodic and working memory. Although duration of methamphetamine use was linked to disinhibition, other patterns of methamphetamine use (including dose and frequency) were not consistently related to performance.

CONCLUSIONS

Methamphetamine dependence impacts inhibitory control and decision-making, whereas lower IQ associates with memory/working memory deficits among methamphetamine users. Findings suggest the need to target disinhibition and impulsive decision-making as part of methamphetamine dependence treatment, while buffering the impact of IQ on memory systems.

White matter fiber density abnormalities in cognitively normal adults at risk for late-onset Alzheimer's disease

Tau accumulation affecting white matter tracts is an early neuropathological feature of late-onset Alzheimer's disease (LOAD). There is a need to ascertain methods for the detection of early LOAD features to help with disease prevention efforts. The microstructure of these tracts and anatomical brain connectivity can be assessed by analyzing diffusion MRI (dMRI) data. Considering that family history increases the risk of developing LOAD, we explored the microstructure of white matter through dMRI in 23 cognitively normal adults who are offspring of patients with Late-Onset Alzheimer's Disease (O-LOAD) and 22 control subjects (CS) without family history of AD. We also evaluated the relation of white matter microstructure metrics with cortical thickness, volumetry, in vivo amyloid deposition (with the help of PiB positron emission tomography -PiB-PET) and regional brain metabolism (as FDG-PET) measures. Finally we studied the association between cognitive performance and white matter microstructure metrics. O-LOAD exhibited lower fiber density and fractional anisotropy in the posterior portion of the corpus callosum and right fornix when compared to CS. Among O-LOAD, reduced fiber density was associated with lower amyloid deposition in the right hippocampus, and greater cortical thickness in the left precuneus, while higher mean diffusivity was related with greater cortical thickness of the right superior temporal gyrus. Additionally, compromised white matter microstructure was associated with poorer semantic fluency. In conclusion, white matter microstructure metrics may reveal early differences in O-LOAD by virtue of parental history of the disorder, when compared to CS without a family history of LOAD. We demonstrate that these differences are associated with lower fiber density in the posterior portion of the corpus callosum and the right fornix.

Predicting Cognitive Decline and Dementia with the Newly Normed SKT Short Cognitive Performance Test

Objective

The aim of this article was to determine the criterion-related validity of the newly normed SKT (Syndrom-Kurztest) Short Cognitive Performance Test with the onset of dementia as the predicted criterion.

Methods

The cognitive ability was tested with the SKT in a sample of 546 cognitively healthy adults aged 65-85 years. New cases of mild cognitive impairment (MCI) or dementia were determined in 3 follow-up investigations at 1-year intervals. Each participant's cognitive status was rated on the Clinical Dementia Rating Scale. The cognitive status according to the SKT is presented in terms of a traffic light system.

Results

Based on Kaplan-Meier estimators, the trajectories of the different SKT traffic light labels were investigated over 3 years. The trajectories were significantly different, representing differential risks for dementia onset. In comparison to the green group, the hazard ratio (HR) for the development of dementia and MCI amounted to HR 6.63 (95% CI 2.75-15.96) and HR 2.34 (95% CI 1.37-3.99), respectively, in the yellow group, and to HR 25.40 (95% CI 10.73-60.14) and HR 3.83 (95% CI 1.86-7.86), respectively, in the red group.

Conclusions

The newly normed SKT showed a high predictive validity for the onset of dementia.

MACE for the Diagnosis of Dementia and MCI: 3-Year Pragmatic Diagnostic Test Accuracy Study

BACKGROUND/AIMS

The Mini-Addenbrooke's Cognitive Examination (MACE) is a relatively new short cognitive screening instrument for the detection of patients with dementia and mild cognitive impairment (MCI). Few studies of the MACE have been reported hitherto. The aim of this study was to undertake a pragmatic diagnostic test accuracy study of MACE in a large cohort of patients seen in a dedicated cognitive disorders clinic.

METHODS

MACE was administered to consecutive patients referred to a neurology-led Cognitive Function Clinic over the course of 3 years to assess its performance for the diagnosis of dementia and MCI using various test metrics.

RESULTS

In a cohort of 599 patients, the prevalence of dementia and MCI by criterion diagnosis was 0.17 and 0.29, respectively. MACE had a high sensitivity (> 0.9) and negative predictive values (> 0.8) with large effect sizes (Cohen's d > 1) for the diagnosis of both dementia and MCI but a low specificity (< 0.5) and positive predictive values (≤0.5).

CONCLUSION

MACE is an acceptable test for the assessment of cognitive complaints in a secondary care setting with good metrics for identifying cases of both dementia and MCI.

Identifying brain changes related to cognitive aging using VBM and visual rating scales

Aging is often associated with changes in brain structures as well as in cognitive functions. Structural changes can be visualized with Magnetic Resonance Imaging (MRI) using voxel-based grey matter morphometry (VBM) and visual rating scales to assess atrophy level. Several MRI studies have shown that possible neural correlates of cognitive changes can be seen in normal aging. It is still not fully understood how cognitive function as measured by tests and demographic factors are related to brain changes in the MRI. We recruited 55 healthy elderly subjects aged 50–79 years. A battery of cognitive tests was administered to all subjects prior to MRI scanning. Our aim was to assess correlations between age, sex, education, cognitive test performance, and the said two MRI-based measures. Our results show significant differences in VBM grey matter volume for education level (≤ 12 vs. > 12 years), with a smaller amount of grey matter volume in subjects with lower educational levels, and for age in interaction with education, indicating larger grey matter volume for young, higher educated adults. Also, grey matter volume was found to be correlated with working memory function (Digit Span Backward). Furthermore, significant positive correlations were found between visual ratings and both age and education, showing larger atrophy levels with increasing age and decreasing level of education. These findings provide supportive evidence that MRI-VBM detects structural differences for education level, and correlates with educational level and age, and working memory task performance.

•

VBM grey matter volume differences were significant for the interaction of age and education level.

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Grey matter volume correlated with education level and working memory function (Digit Span Backward).

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Significant correlations were found between visual rating scales and both age and education.

•

VBM is able to detect structural differences for age and education, and correlates with education and working memory.

Characteristics of Mild Cognitive Impairment Using the Thai Version of the Consortium to Establish a Registry for Alzheimer's Disease Tests: A Multivariate and Machine Learning Study

BACKGROUND

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) developed a neuropsychological battery (CERAD-NP) to screen patients with Alzheimer's dementia. Mild cognitive impairment (MCI) has received attention as a pre-dementia stage.

OBJECTIVES

To delineate the CERAD-NP features of MCI and their clinical utility to externally validate MCI diagnosis.

METHODS

The study included 60 patients with MCI, diagnosed using the Clinical Dementia Rating, and 63 normal controls. Data were analysed employing receiver operating characteristic analysis, Linear Support Vector Machine, Random Forest, Adaptive Boosting, Neural Network models, and t-distributed stochastic neighbour embedding (t-SNE).

RESULTS

MCI patients were best discriminated from normal controls using a combination of Wordlist Recall, Wordlist Memory, and Verbal Fluency Test. Machine learning showed that the CERAD features learned from MCI patients and controls were not strongly predictive of the diagnosis (maximal cross-validation 77.2%), whilst t-SNE showed that there is a considerable overlap between MCI and controls.

CONCLUSIONS

The most important features of the CERAD-NP differentiating MCI from normal controls indicate impairments in episodic and semantic memory and recall. While these features significantly discriminate MCI patients from normal controls, the tests are not predictive of MCI.

Schizophrenia moderates the relationship between white matter integrity and cognition

Cognitive impairment is a primary feature of schizophrenia, with alterations in several cognitive domains appearing in the pre-morbid phase of the disorder. White matter microstructure is also affected in schizophrenia and considered to be related to cognition, but the relationship of the two is unclear. As interaction between cognition and white matter structure involves the interplay of several brain structures and cognitive abilities, investigative methods which can examine the interaction of multiple variables are preferred. A multiple-groups structural equation model (SEM) was used to assess the relationship between diffusion tension imaging data (fractional anisotropy of selected white matter tracts) and cognitive abilities of 196 subjects - 135 healthy subjects and 61 patients with schizophrenia. It was found that multiple-indicators, multiple-causes model best fitted the data analysed. Schizophrenia moderated the relation of white matter function on cognition with a large effect size. This paper extends previous work on modelling intelligence within a SEM framework by incorporating neurological elements into the model, and shows that white matter microstructure in patients with schizophrenia interacts with cognitive abilities.

Impulsivity predicts poorer improvement in quality of life during early treatment for people with methamphetamine dependence

BACKGROUND AND AIMS

Methamphetamine dependence is associated with heightened impulsivity and diminished quality of life, but the link between impulsivity and changes in quality of life during treatment has not been examined. We aimed to investigate how different elements of impulsivity predict change in quality of life in the 6 weeks after engaging in treatment.

DESIGN

Longitudinal, observational cohort study.

SETTING

Public and private detoxification and rehabilitation facilities in metropolitan Melbourne, Australia.

PARTICIPANTS

One hundred and eight individuals with methamphetamine dependence (81 male) tested within 3 weeks of commencing treatment; 80 (74%) were followed-up at 6 weeks.

MEASUREMENTS

The Continuous Performance Test-2 measured impulsive action (cognitive and motor impulsivity); the Delay Discounting Task measured impulsive choice. Quality of life was measured with the World Health Organization Quality of Life Scale-Brief, which includes social, psychological, physical and environment domains. Control variables included age, gender, estimated IQ, depression severity score, methamphetamine dependence severity score, cannabis dependence severity score and treatment modality.

FINDINGS

We found that all three forms of impulsivity were significant predictors of change in the social domain: motor impulsivity (β = -0.54, P = 0.013), cognitive impulsivity (β = -0.46, P = 0.029) and impulsive choice (β = -0.26, P = 0.019). Change in the psychological domain was predicted significantly by motor impulsivity (β = -0.45, P = 0.046). Control variables of age and depression were associated significantly with changes in the physical domain.

CONCLUSIONS

In Australian methamphetamine-dependent individuals, elevated impulsivity predicts lower improvement of social and psychological quality of life in the first 6-9 weeks of treatment.

Autobiographical memory deficits in patients with depression follow a temporal distribution

Autobiographical memory deficits are known in depression. The temporal distribution thereof across periods of life has rarely been considered yet. Autobiographical memories for 5 life periods were investigated in 27 depressed in-patients and compared to 31 matched healthy controls using the Bielefelder Autobiographisches Gedächtnis Inventar. Depressed patients reported significantly less details in memories dating from childhood to 30 years, correlating with severity of depression. Memories from childhood and recent periods were less positive in depressed patients. Thus, we found a distinct pattern of autobiographical memory deficits in depressed patients. Possible etiological factors, however, need further investigations.

Correlating quantitative tractography at 3T MRI and cognitive tests in healthy older adults

This study used diffusion tensor imaging tractography at 3 T MRI to relate cognitive function to white matter tracts in the brain. Brain T2 fluid attenuated inversion recovery-weighted and diffusion tensor 3 T MRI scans were acquired in thirty-three healthy participants without mild cognitive impairment or dementia. They completed a battery of neuropsychological tests including the Montreal Cognitive Assessment, Stroop test, Trail Making Test B, Wechsler Memory Scale-III Longest span forward, Wechsler Memory Scale-III Longest span backward, Mattis Dementia Rating Scale, California Verbal Learning Test Version II Long Delay Free Recall, and Letter Number Sequencing. Tractography was generated by the Fiber Assignment by Continuous Tracking method. The corpus callosum, cingulum, long association fibers, corticospinal/bulbar tracts, thalamic projection fibers, superior cerebellar peduncle, middle cerebellar peduncle and inferior cerebellar peduncle were manually segmented. The fractional anisotropy (FA) and mean diffusivity (MD) of these tracts were quantified. We studied the association between cognitive test scores and the MD and FA of tracts while controlling for age and total white matter hyperintensities volume. Worse scores on the Stroop test was associated with decreased FA of the corpus callosum, corticospinal/bulbar tract, and thalamic projection tracts. Scores on the other cognitive tests were not associated with either the FA or MD of measured tracts. In healthy persons the Stroop test appears to be a better predictor of the microstructural integrity of white matter tracts measured by DTI tractography than other cognitive tests.

Neuropsychological Measures that Predict Progression from Mild Cognitive Impairment to Alzheimer's type dementia in Older Adults: a Systematic Review and Meta-Analysis

This study aimed to determine the extent to which cognitive measures can predict progression from mild cognitive impairment (MCI) to Alzheimer’s type dementia (AD), assess the predictive accuracy of different cognitive domain categories, and determine whether accuracy varies as a function of age and length of follow-up. We systematically reviewed and meta-analyzed data from longitudinal studies reporting sensitivity and specificity values for neuropsychological tests to identify individuals with MCI who will develop AD. We searched articles in Medline, Cochrane, EMBASE, PsycINFO, and the Web of Science. Methodological quality was assessed using the STARDem and QUADAS standards. Twenty-eight studies met the eligibility criteria (2365 participants) and reported predictive values from 61 neuropsychological tests with a 31-month mean follow-up. Values were pooled to provide combined accuracy for 14 cognitive domains. Many domains showed very good predictive accuracy with high sensitivity and specificity values (≥ 0.7). Verbal memory measures and many language tests yielded very high predictive accuracy. Other domains (e.g., executive functions, visual memory) showed better specificity than sensitivity. Predictive accuracy was highest when combining memory measures with a small set of other domains or when relying on broad cognitive batteries. Cognitive tests are excellent at predicting MCI individuals who will progress to dementia and should be a critical component of any toolkit intended to identify AD at the pre-dementia stage. Some tasks are remarkable as early indicators, whereas others might be used to suggest imminent progression.

Diagnosing mild cognitive impairment in Parkinson's disease: which tests perform best in the Italian population?

Mild cognitive impairment (MCI) is common in patients with Parkinson's disease (PD) and should be recognized early because it represents a predictor of PD-related dementia and worse disease course. Diagnostic criteria for PD-related MCI (PD-MCI) have recently been defined by a Movement Disorders Society (MDS) task force. The present study explored which neuropsychological tests perform best for a level II (i.e., comprehensive neuropsychological assessment) diagnosis of PD-MCI according to the MDS task force criteria in Italian-speaking PD patients. To this aim, we assessed a comprehensive 23-item neuropsychological battery, derived the best-performing 10-test battery (i.e., two tests per domain for each of the five cognitive domains), and explored its accuracy for diagnosing PD-MCI in comparison to the full battery in a group of PD patients. A secondary aim was to explore the role of this battery for subtyping PD-MCI according to single-domain vs. multiple-domain involvement. The 10-test battery showed 73% sensitivity and 100% specificity for diagnosing PD-MCI, and 69% sensitivity and 100% specificity for PD-MCI subtyping. In patients older than 70 years, we derived a slightly different 10-test battery with 84% sensitivity and 100% specificity for PD-MCI diagnosis, and 86% sensitivity and 100% specificity for PD-MCI subtyping. These 10-item neuropsychological batteries might represent a good trade-off between diagnostic accuracy and time of application, and their role in PD-MCI diagnosis and subtyping should be further explored in future prospective studies.

Spatial navigation and risk of cognitive impairment: A prospective cohort study

INTRODUCTION

Spatial navigation deficits are reported in dementia, but their temporal relationship to cognitive decline is not established.

METHODS

This is a prospective cohort study in 442 nondemented adults (mean age 79.9 years). Spatial navigation measured with the Floor Maze Test and reported as immediate maze time (IMT) and delayed maze time (DMT). Predementia syndromes, mild cognitive impairment syndrome (MCI) and motoric cognitive risk syndrome (MCR), were primary outcomes.

RESULTS

Over a mean follow-up of 16.5 ± 13.7 months, 41 participants developed MCI and 30 participants developed MCR. In Cox models adjusted for age, sex, education, cognitive status, comorbid illnesses, and maze errors, a 10-second increment on IMT predicted incident MCI (adjusted hazard ratio [aHR]: 1.25; 95% confidence interval [CI]: 1.06-1.48) and MCR (aHR: 1.53; 95% CI: 1.23-1.90). DMT predicted MCR but not MCI.

DISCUSSION

Spatial navigation performance predicted predementia syndromes in aging and implicates navigational impairments as an early feature in dementias.

The Differential Effects of Alzheimer's Disease and Lewy Body Pathology on Cognitive Performance: a Meta-analysis

Differential diagnosis of Alzheimer's disease (AD) from normal aging and other dementia etiologies is imperative for disease specific treatment options and long-term care planning. Neuropathological confirmation is the gold standard for neurodegenerative disease diagnosis, yet most published studies examining the use of neuropsychological tests in the differential diagnosis of dementia rely upon clinical diagnostic outcomes. The present study undertook a meta-analytic review of the literature to identify cognitive tests and domains that allow for the differentiation of individuals with AD pathology from individuals with dementia with Lewy Bodies (DLB) pathology and pathology-free individuals. A comprehensive literature search yielded 14 studies that met the inclusion criteria for the present meta-analysis. Six studies comprised 222 decedents with AD compared to 433 normal controls, and eight studies comprised 431 cases of AD compared to 155 decedents with DLB. Results revealed that the effect of having neuropathologically confirmed AD versus DLB lowered performance in the memory domain, and having DLB decreased performance in the visuospatial domain. No single test differed significantly across the AD and DLB groups. For the AD and pathology free comparison, results indicated that that AD was associated with poorer performance on the memory and language domains. With respect to specific cognitive tests, AD produced lower scores on list learning tests, category fluency, and the Digit Symbol substitution test. The limited number of studies meeting inclusion criteria warrants formulation of guidelines for reporting in clinico-pathological studies; suggested guidelines are provided.

Assessment of Cognitive Outcome Measures in Teenagers with 15q13.3 Microdeletion Syndrome

15q13.3 microdeletion syndrome causes a spectrum of cognitive disorders, including intellectual disability and autism. We aimed to determine if any or all of three cognitive testing systems (the KiTAP, CogState, and Stanford-Binet) are suitable for assessment of cognitive function in affected individuals. These three tests were administered to ten individuals with 15q13.3 microdeletion syndrome (14-18 years of age), and the results were analyzed to determine feasibility of use, potential for improvement, and internal consistency. It was determined that the KiTAP, CogState, and Stanford-Binet are valid tests of cognitive function in 15q13.3 microdeletion patients. Therefore, these tests may be considered for use as objective outcome measures in future clinical trials, assessing change in cognitive function over a period of pharmacological treatment.

Accounting for ethnic-cultural and linguistic diversity in neuropsychological assessment of patients with drug-resistant epilepsy: A retrospective study

Neuropsychological assessment is critical in both diagnosis and prognosis of patients with epilepsy. Beyond electrophysiological and anatomical alterations, other factors including different ethnic-cultural and linguistic backgrounds might affect neuropsychological performance. Only a few studies considered migration and acculturation effects and they typically concerned nonclinical samples. The current study aimed at investigating the influence of ethnic background and time spent in Italy on a full neuropsychological battery administered to both Italian and foreign-born patients and at providing a brief interview for obtaining relevant information on each patient's transcultural and language-related history. Clinical reports from 43 foreign-born patients with drug-resistant epilepsy were collected from the archives of Milan Niguarda Hospital. Epileptogenic zone, age, education, profession, illness duration, seizure frequency, handedness, and gender were considered in selecting 43 Italian controls. Ethnicity (Italian/foreign-born) and years spent in Italy were analyzed as main predictors on 21 neuropsychological scales by means of General(ized) Linear Models. An additional analysis studied two composite scores of overall verbal and nonverbal abilities. Ethnicity significantly affected the following: the verbal overall score, Verbal Fluency, Naming, Token-test, Digit Span, Attentional Matrices, Trail-Making-Test, Line-Orientation-Test, and Raven matrices; no effects were found on the nonverbal overall score, Word Pairs Learning, Episodic Memory, reading accuracy, visual span, Bells test, Rey Figure, and face memory and recognition. No significant effects of years spent in Italy emerged. While years spent in Italy does not predict neuropsychological performance, linguistic background had a strong impact on it. With respect to Italian-speaking patients, those who were foreign-born showed large task-related variability, with an especially low performance on language-related tests. Hence, language tests should not be considered as valid measures of neuropsychological impairment in this population, not even in foreign-born patients with good Italian fluency. Clinicians should consider such asymmetries in order to improve the accuracy of neuropsychological assessment of foreign-born patients.

Cognitive profiling of Parkinson disease patients with mild cognitive impairment and dementia

BACKGROUND

Prevalence of mild cognitive impairment (MCI) and dementia in Parkinson disease (PD) is variable because different classification criteria are applied and there is lack of consensus about neuropsychological tests and cut-off used for cognitive profiling. Given the important therapeutic consequences for patient management, we aimed at identifying suitable diagnostic cognitive tests and respective screening cut-off values for MCI and dementia in PD (PDD).

METHODS

We evaluated 105 PD patients using an extensive neuropsychological battery categorized as PD without cognitive impairment (PD-CNT) (35%), PD-MCI (47%) and PDD (18%) based on established criteria and calculated Receiver Operating Characteristic (ROC) curves.

RESULTS

We found different sensitivity and specificity among neuropsychological tests in detecting PD-MCI and PDD. In particular performance in attention/set shifting, verbal memory and language abilities, discriminated both PD-MCI and PDD from PD-CNT. Abilities involved mainly in semantic retrieval mechanisms discriminated PD-CNT from PD-MCI but also PD-MCI from PDD. Finally deficits in executive and visual-spatial abilities were only affected in PDD.

CONCLUSION

Our data point to an independent and different load of each test in defining different PD cognitive statuses. These findings can help selection of appropriate cognitive batteries in longitudinal studies and definition of stage-specific therapeutic targets.

Yamaguchi Facial Expression-Making Task in Alzheimer's Disease: A Novel and Enjoyable Make-a-Face Game

Background

To assess the ability to make emotional facial expressions, we newly developed the Yamaguchi facial expression-making task (Y-FEMT).

Method

We recruited 20 normal controls and 61 outpatients: 10 with amnestic mild cognitive impairment (aMCI), 34 with mild Alzheimer's disease (AD), and 17 with moderate AD. In the Y-FEMT, smile and anger expressions were made by arranging face parts. We examined the relationship between each Y-FEMT score and the Mini-Mental State Examination (MMSE) score or overlapping figure identification test (Fig-test).

Results

The Total score (0–20) was nearly achieved in controls (18.9 ± 1.4) and declined with AD progression (aMCI 17.2 ± 2.4, mild AD 15.7 ± 2.6, moderate AD 12.3 ± 2.7). The Anger score (0–10) was significantly lower than the Smile score (0–10) in mild and moderate AD (p = 0.007 and p = 0.006, respectively). The Structure score (0–6 each) correlated well with both the MMSE score (r = 0.44, p < 0.001) and Fig-test (r = 0.45, p < 0.001), whereas the Expression score (0–4 each) correlated only with the MMSE score (r = 0.33, p = 0.01). The Subjective scores (0–4), evaluated by 10 therapists, highly correlated with the Total score. Additionally, the Y-FEMT promoted laughter and a convivial atmosphere.

Conclusion

The Y-FEMT pleasantly assessed the ability to make emotional facial expressions without special equipment. Furthermore, the Y-FEMT may provide helpful clues for caregivers to achieve good communication with AD patients for better care.