Executive Impairment Research Articles

Associations between executive function impairment and biochemical abnormalities in depressed adolescents with non-suicidal self-injury

BackgroundH protons magnetic resonance spectroscopy (1H-MRS) has been used to detect the biochemical metabolism changes and the mechanism of executive dysfunction in major depressive disorder (MDD). While, finding information associated with non-suicidal self-injury (NSSI) among adolescents with MDD is challenging. The present study aimed to examine the executive function and biochemical metabolism alterations, as well as to elucidate their associations in depressed adolescents with NSSI. MethodsA total of 86 adolescents with MDD (40 with NSSI, and 46 without NSSI) and 28 healthy controls were recruited in the current study. The executive function was assessed by Digital symbol test (DST), Wisconsin Card Sorting Test (WCST), Trail Making Test, part B (TMT-B), and Verbal fluency (VF). Bilateral metabolite levels of the prefrontal cortex (PFC), anterior cingulated cortex (ACC), lenticular nucleus (LN) of basal ganglia and thalamus were obtained by 1H-MRS at 3.0 T, and then the ratios of N-acetyl aspartate (NAA) and choline-containing compounds (Cho) to creatine (Cr) were determined, respectively. Finally, association analysis was conducted to investigate their relationships. ResultsThe depressed adolescents with NSSI showed significantly lower VF scores than those without NSSI and healthy controls. We also found significantly higher NAA/Cr ratios in the right thalamus, while significantly lower Cho/Cr ratios in the right thalamus of NSSI group than the MDD without NSSI group and healthy controls. And NSSI group also showed lower NAA/Cr ratio in the right LN than the MDD without NSSI group. For MDD with NSSI, the NAA/Cr ratios of the left thalamus were positively correlated with the time of TMTB and the Cho/Cr ratios of the left ACC were positively correlated with the VF scores. ConclusionsDepressed adolescents with NSSI may have executive dysfunction and NAA and Cho metabolism abnormalities in the thalamus. And the NAA/Cr ratios of the right LN could distinguish NSSI from depressed adolescents. Further, the executive dysfunction may be associated with the abnormal NAA metabolism in the left thalamus and ACC.

Proton magnetic resonance spectroscopy in frontotemporal lobar degeneration-related syndromes

There is an urgent need for a better understanding of the pathophysiology of cognitive impairment in syndromes associated with frontotemporal lobar degeneration. Here, we used magnetic resonance spectroscopy to quantify metabolite deficits in sixty patients with a clinical syndrome associated with frontotemporal lobar degeneration (behavioral variant frontotemporal dementia n = 11, progressive supranuclear palsy n = 26, corticobasal syndrome n = 11, primary progressive aphasias n = 12), and 38 age- and sex-matched healthy controls. We measured nine metabolites in the right inferior frontal gyrus, superior temporal gyrus and right primary visual cortex. Metabolite concentrations were corrected for age, sex, and partial volume then compared with cognitive and behavioral measures using canonical correlation analysis. Metabolite concentrations varied significantly by brain region and diagnosis (region x metabolite x diagnosis interaction F(64) = 1.73, p < 0.001, corrected for age, sex, and atrophy within the voxel). N-acetyl aspartate and glutamate concentrations were reduced in the right prefrontal cortex in behavioral variant frontotemporal dementia and progressive supranuclear palsy, even after partial volume correction. The reduction of these metabolites was associated with executive dysfunction and behavioral impairment (canonical correlation analysis R = 0.85, p < 0.001).

Discharge Rehabilitation Measures Predict Activity Limitations in Patients With Stroke 6 Months After Inpatient Rehabilitation.

The aim of this study was to identify rehabilitation measures at discharge from acute inpatient stroke rehabilitation that predict activity limitations at 6 mos postdischarge. This is a retrospective analysis of a prospective, longitudinal, observational cohort study. It was conducted in an acute inpatient rehabilitation unit at an urban, academic medical center. Activity limitations in patients ( N = 141) with stroke of mild-moderate severity were assessed with the activity measure for post-acute care at inpatient stroke rehabilitation discharge and 6-mo follow-up. Rehabilitation measures at discharge were investigated as predictors for activity limitations at 6 mos. Measures of balance (Berg Balance Scale), functional limitations in motor-based activities (functional independence measure-motor subscore), and motor impairment (motricity index), in addition to discharge activities measure for post-acute care scores, strongly predicted activity limitations in basic mobility and daily activities at 6 mos (51% and 41% variance explained, respectively). Functional limitations in cognition (functional independence measure-cognitive subscore) and executive function impairment (Trail Making Test-part B), in addition to the discharge activities measure for post-acute care score, modestly predicted limitations in cognitively based daily activities at 6 mos (12% of variance). Standardized rehabilitation measures at inpatient stroke rehabilitation discharge can predict future activity limitations, which may improve prediction of outcome post-stroke and aid in postdischarge treatment planning.

Development of a generic version of the multiple errands test for severe acquired brain injuries

Background Impairment of executive functions is a frequent and disabling consequence of brain injury. In 1991, Shallice and Burgess elaborated the Multiple Errand Test (MET) to assess everyday troubles associated with this impairment. Objective Our first aim was to create a generic version of MET (MET-G) readily adaptable to different settings and for retesting. The second aim was to validate the revised version to detect executive impairment in individuals with severe ABI. Methods An inter-professional team of experts in neurorehabilitation created a revised version of MET. Twenty-one patients with sABI (severe Acquired Brain Injury) and a control group of 20 neurologically healthy subjects, took part in the testing of MET-G. Results MET-G clearly distinguished people with sABI from healthy controls based on Total error score, task completion, and rule breaking. The test showed good inter-rater reliability and internal consistency. Conclusions The new, generic version of MET was able to differentiate adults with sABI from controls and proved to be a good tool for evaluating executive functions in these patients in daily-life contexts. Indications on how to adapt the test to different contexts and different scoring modalities are provided.

Executive control deficits and lesion correlates in acute left hemisphere stroke survivors with and without aphasia.

In contrast to the traditional definition of the disorder, many individuals with aphasia exhibit non-linguistic cognitive impairments, including executive control deficits. Classic lesion studies cite frontal lobe damage in executive dysfunction, but more recent lesion symptom-mapping studies in chronic aphasia present mixed results. In this study, we compared executive control abilities of acute stroke survivors with and without aphasia and investigated lesion correlates of linguistic and non-linguistic cognitive tasks. Twenty-nine participants with acute left hemisphere stroke resulting in aphasia (n = 14) or no aphasia (n = 15) completed clinical MRI and testing, including three NIH Toolbox Cognition Batteries (Pattern Comparison Processing Speed, Flanker Inhibitory Control and Attention, and Dimensional Change Card Sort Tests) and the Boston Naming Test. We compared performance between groups using Wilcoxon rank sum tests. We used Least Absolute Shrinkage and Selection Operator Regression to identify neural markers (percent regional damage, hypoperfusion within vascular territories, and total lesion volume) of executive control deficits and anomia. Group performance was comparable on the Pattern Comparison Processing Speed Test, but people with aphasia had poorer standard scores, lower accuracy, and slower response times on the Dimensional Change Card Sort Test than people without aphasia. Damage to extrasylvian regions (dorsolateral prefrontal cortex, intraparietal sulcus) was related to executive control deficits, whereas language network damage (to inferior frontal and superior and posterior middle temporal gyri) was linked to naming impairments. These results suggest people with aphasia can exhibit comorbid executive control impairments linked to damage outside classic language network areas.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11682-021-00580-y.

Modulation of Dorsolateral Prefrontal Cortex Glutamate/Glutamine Levels Following Repetitive Transcranial Magnetic Stimulation in Young Adults With Autism.

Altered excitatory and inhibitory neurotransmission has been implicated in autism spectrum disorder (ASD). Interventions using repetitive transcranial magnetic stimulation (rTMS) to enhance or inhibit cortical excitability are under study for various targets, though the mechanistic effects of rTMS have yet to be examined in ASD. Here, we examined whether an excitatory rTMS treatment course modulates glutamatergic (Glx) or γ-aminobutyric acid (GABA) metabolite levels in emerging adults with ASD. Twenty-eight participants with ASD and executive function impairment [23.3 ± 4.69 years; seven-female] underwent two magnetic resonance spectroscopy (MRS) scans of the left dorsolateral prefrontal cortex (DLPFC). MRS scans were acquired before and after participants with ASD were randomized to receive a 20-session course of active or sham rTMS to the DLPFC. Baseline MRS data was available for 19 typically developing controls [23.8 ± 4.47 years; six-female]. Metabolite levels for Glx and GABA+ were compared between ASD and control groups, at baseline, and metabolite level change, pre-to-post-rTMS treatment, was compared in ASD participants that underwent active vs. sham rTMS. Absolute change in Glx was greater in the active vs. sham-rTMS group [F(1,19) = 6.54, p = 0.02], though the absolute change in GABA+ did not differ between groups. We also examined how baseline metabolite levels related to pre/post-rTMS metabolite level change, in the active vs. sham groups. rTMS group moderated the relation between baseline Glx and pre-to-post-rTMS Glx change, such that baseline Glx predicted Glx change in the active-rTMS group only [b = 1.52, SE = 0.32, t(18) = 4.74, p < 0.001]; Glx levels increased when baseline levels were lower, and decreased when baseline levels were higher. Our results indicate that an interventional course of excitatory rTMS to the DLPFC may modulate local Glx levels in emerging adults with ASD, and align with prior reports of glutamatergic alterations following rTMS. Interventional studies that track glutamatergic markers may provide mechanistic insights into the therapeutic potential of rTMS in ASD.Clinical Trial Registration: Clinicaltrials.gov (ID: NCT02311751), https://clinicaltrials.gov/ct2/show/NCT02311751?term=ameis&rank=1; NCT02311751.

Neurocognitive deficits among adult road traffic accident victims at the University Teaching Hospital, Lusaka, Zambia

Introduction: Road traffic accidents (RTAs) are of growing public health importance worldwide contributing significantly to the global disease burden thus public health experts worldwide concede that there is a global epidemic of RTAs. Exposure to RTAs may be associated with changes in brain functioning and cognitive performance. Objective: This study sought to contribute to the understanding of the neurocognitive deficits among adult victims of RTAs. Methodology: It is a cross-sectional study (descriptive in nature). Cognitive profiles of the affected participants were assessed by selected tests from the International Neurobehavioral test battery. The quality of life was assessed by application of the World Health Organisation Quality of Life (WHOQOL) questionnaire. The primary data obtained was analyzed using descriptive and inferential statistics using SPSS. Results: Twenty-seven (27) RTA victims out of Thirty (30) had executive functioning impairment with a Domain Deficit Score (DDS) of ≥ 0.5 and all the RTA victims in the study had speed of information processing impairment with a Domain Deficit Score (DDS) of ≥ 0.5. There was no significant statistical gender difference in neurocognitive functioning (Executive functioning F=0.85, P=0.36; Speed of information processing F=0.98, P=0.33). Compromised quality of life among adult victims of road traffic accidents was confirmed (P=0.005). Conclusion: This study shows an association between RTA and neurocognitive functioning in adult victims. Findings of this study show the presence of neuropsychological impairments in the two domains assessed (executive functioning and speed of information processing). The study indicates that RTA significantly compromises the quality of life.

Depression and learning problems in children: Executive function impairments and inattention as mediators

This study examines the relationship between depression and learning problems in children, focusing on the mediating role of executive function impairments and inattention. A sample of 115 children, aged 7 to 12 years, who had difficulties in school activities, were tested over the past three years, with different measures assessed by different raters. Regression analyses were employed in analyzing the data. The psychometric tests used were Child Depression Inventory (CDI) and Conners 3rdEdition. Children with a high level of depressive symptoms have also a very high level of learning problems, executive function impairments and inattention. Executive function impairments and inattention add significant explanatory variance for learning problems in school-aged children over and above depression. Executive function impairments and inattention have a partial mediating effect on the relationship between depression and learning problems. The assessment of the executive functions and attention is an important part in the assessment of children with depression; intervention and treatment programs for depression should include components focused on executive functions and attention.

Structural-covariance networks identify topology-based cortical-thickness changes in children with persistent executive function impairments after traumatic brain injury

Paediatric traumatic brain injury (pTBI) results in inconsistent changes to regional morphometry of the brain across studies. Structural-covariance networks represent the degree to which the morphology (typically cortical-thickness) of cortical-regions co-varies with other regions, driven by both biological and developmental factors. Understanding how heterogeneous regional changes may influence wider cortical network organization may more appropriately capture prognostic information in terms of long term outcome following a pTBI. The current study aimed to investigate the relationships between cortical organisation as measured by structural-covariance, and long-term cognitive impairment following pTBI. T1-weighted magnetic resonance imaging (MRI) from n = 83 pTBI patients and 33 typically developing controls underwent 3D-tissue segmentation using Freesurfer to estimate cortical-thickness across 68 cortical ROIs. Structural-covariance between regions was estimated using Pearson's correlations between cortical-thickness measures across 68 regions-of-interest (ROIs), generating a group-level 68 × 68 adjacency matrix for patients and controls. We grouped a subset of patients who underwent executive function testing at 2-years post-injury using a neuropsychological impairment (NPI) rule, defining impaired- and non-impaired subgroups. Despite finding no significant reductions in regional cortical-thickness between the control and pTBI groups, we found specific reductions in graph-level strength of the structural covariance graph only between controls and the pTBI group with executive function (EF) impairment. Node-level differences in strength for this group were primarily found in frontal regions. We also investigated whether the top n nodes in terms of effect-size of cortical-thickness reductions were nodes that had significantly greater strength in the typically developing brain than n randomly selected regions. We found that acute cortical-thickness reductions post-pTBI are loaded onto regions typically high in structural covariance. This association was found in those patients with persistent EF impairment at 2-years post-injury, but not in those for whom these abilities were spared. This study posits that the topography of post-injury cortical-thickness reductions in regions that are central to the typical structural-covariance topology of the brain, can explain which patients have poor EF at follow-up.

Enhancement of task-switching performance with transcranial direct current stimulation over the right lateral prefrontal cortex

Switching between two or more tasks is a key component in our modern world. Task switching, however, requires time-consuming executive control processes and thus produces performance costs when compared to task repetitions. While executive control during task switching has been associated with activation in the lateral prefrontal cortex (lPFC), only few studies so far have investigated the causal relation between lPFC activation and task-switching performance by modulating lPFC activation. In these studies, the results of lPFC modulation were not conclusive or limited to the left lPFC. In the present study, we aimed to investigate the effect of non-invasive transcranial direct current stimulation [tDCS; anodal tDCS (1 mA, 20 min) vs. cathodal tDCS (1 mA, 20 min) vs. sham tDCS (1 mA, 30 s)] over the right inferior frontal junction on task-switching performance in a well-established task-switching paradigm. In response times, we found a significant effect of tDCS Condition (atDCS, ctDCS vs. sham) on task-switching costs, indicating the modulation of task-switching performance by tDCS. In addition, we found a task-unspecific tDCS Condition effect in the first experimental session, in which participants were least familiar with the task, indicating a general enhancement of task performance in both task repetitions and task-switching trials. Taken together, our study provides evidence that the right lPFC is involved in task switching as well as in general task processing. Further studies are needed to investigate whether these findings can be translated into clinically relevant improvement in older subjects or populations with executive function impairment.

Writing in prodromal and mild dementia with Lewy bodies: an exploratory and preliminary study

In order to better characterize their cognitive profiles, our speech therapy study aimed to assess the ability of prodromal or mild DLB patients in writing production. Seventeen prodromal to mild DLB patients underwent written tests selected from the French language assessment corpus GREMOTS. The protocol included dictations of words, logatoms, and sentences. These tests were completed with a self-assessment questionnaire about writing disability and an observational table of writing behavior. 18% of patients had a deficit score in dictation of words, 41% of patients had a deficit score in dictation of logatoms and 35% of patients had a deficit score in dictation of sentences. 71% of patients had a subjective complaint about their handwriting quality. The assessment of handwriting quality also showed difficulties for 76% of patients, with graphic motor pattern disorders and motor symptoms associated with parkinsonism dysgraphia. Finally, our results suggest an impact of working memory, attentional and executive function impairments on logatoms production, and an impact of working memory impairment on long sentences production and grammatical agreements. These findings are promising and may improve our knowledge of the prodromal and mild stages of DLB. They may also contribute to improve early diagnosis and clinical practice.

Volume of hippocampal subfields and cognitive deficits in neuromyelitis optica spectrum disorders.

Aquaporin-4 (AQP4) water channel is involved in hippocampal plasticity and is the target of neuromyelitis optica spectrum disorders (NMOSD) autoimmunity. We measured volumes of hippocampal subfields and their association with cognitive performance in AQP4-seropositive NMOSD patients. Global and regional hippocampal volumes were derived from 28 AQP4-seropositive NMOSD patients and 101 healthy controls (HC) from 3D-T1-weighted images. Normalized brain volumes were also calculated. A neuropsychological evaluation, including the Brief Repeatable Battery of Neuropsychological Tests, was performed in patients. Based on HC data, we estimated mean z-scores of volumes in the whole NMOSD group and compared them according to the status of global and domain-selective cognitive impairment. Global cognitive impairment was detected in 46.4% of NMOSD patients, with attentive (60.7%) and executive (21.4%) domains being the most affected. NMOSD patients had left hippocampal atrophy at global (p=0.012) and regional level (fimbria, Cornu Ammonis [CA] 3, molecular layer, dentate gyrus [DG], and subicular complex, p values ranging between 0.033 and <0.001). On the right side the fimbria and hippocampal tail were atrophic (p=0.024 for both). Cognitively impaired patients showed atrophy in the left CA3 and CA4 (p=0.025-0.028), while patients presenting verbal and visual memory impairment had significant CA3 and DG atrophy. Those patients with attentive or executive impairment had preserved brain and hippocampal volumes. NMOSD patients showed hippocampal atrophy associated with verbal and visual memory impairment. Such damage did not explain attention and executive function alterations, which were the most common cognitive deficits in this population.

Inflammation mediates depression and generalized anxiety symptoms predicting executive function impairment after 18 years

IntroductionScar theories propose that elevated depression and anxiety can predispose people to future decreased executive function (EF) via heightened inflammation across decades. However, more longitudinal (versus cross-sectional) research on this topic is needed. ObjectiveWe thus investigated if increased major depressive disorder (MDD), generalized anxiety disorder (GAD), and panic disorder (PD) severity predicted EF decrement 18 years later via heightened inflammation. MethodCommunity-dwelling adults participated in this study. Time 1 (T1) MDD, GAD, and PD severity (Composite International Diagnostic Interview–Short Form), T2 inflammation (interleukin-6, C-reactive protein, and fibrinogen blood levels concentration), and T2 and T3 EF (Brief Test of Adult Cognition by Telephone) were measured. The waves of assessment were spaced approximately 9 years apart. Structural equation modeling was conducted. ResultsHigher T1 MDD and GAD (but not PD) severity forecasted elevated T2 inflammation (Cohen's d = 0.116–0.758). Greater T2 inflammation level predicted lower T3 EF following 9 years (d = -0.782–-0.636). The T1 MDD–T3 EF and T1 GAD–T3 EF negative associations were mediated by T2 inflammation, and explained 38% and 19% of the relations, respectively. Direct effects of higher T1 GAD and MDD predicting lower T3 EF were also observed (d = -0.585–-0.560). Significant effects remained after controlling for socio-demographic, lifestyle, medication use, various illness variables across time, and T2 EF. ConclusionsInflammation may be a mechanism explaining the T1 MDD–T3 EF and T1 GAD–T3 EF relations. Treatments that target inflammation, worry, and/or depression may prevent future EF decline.

EXecutive-Functions Innovative Tool (EXIT 360°): A Usability and User Experience Study of an Original 360°-Based Assessment Instrument.

Over the last few decades, several studies have shown the feasibility, acceptability, and efficacy of VR-based instruments in the early evaluation of executive dysfunction (ED) in psychiatric and neurologic conditions. Due to the negative impact of ED in everyday functioning, identifying innovative strategies for evaluating ED allows clinicians to detect executive impairment early and minimize its effects. This work aimed to test the usability and user experience (UX) of EXecutive-functions Innovative Tool 360° (EXIT 360°), a 360°-based tool for assessing ED. Seventy-six healthy subjects underwent an evaluation that involved (1) usability assessment using System Usability Scale and (2) evaluation of UX using the ICT-Sense of Presence and UX Questionnaire. Results showed a satisfactory level of usability (mean = 75.9 ± 12.8), with good scores for usability and learnability. As regards UX, EXIT 360° showed an absence of negative effects (mean = 1.79 ± 0.95) and high scores in ecological validity (mean = 4.32 ± 0.54) and engagement (mean = 3.76 ± 0.56). Moreover, it obtained good scores in efficiency (mean = 1.84 ± 0.84), originality (mean = 2.49 ± 0.71), and attractiveness (mean = 1.93 ± 0.98). Interestingly, demographic characteristics and technological expertise had no impact on the performance (p > 0.05). Overall, EXIT 360° appeared to be a usable, learn-to-use, engaging, and creative tool with irrelevant negative effects. Further studies will be conducted to evaluate these aspects in the clinical population.

Posterior fronto-medial atrophy reflects decreased loss aversion, but not executive impairment, in alcohol use disorder.

Decreased punishment sensitivity in alcohol use disorder (AUD) might reflect a reduction in the typical human tendency to overweigh negative choice outcomes compared with equivalent positive ones, that is, 'loss aversion.' While this hypothesis is supported by previous reports of reduced loss aversion in AUD, it is still unknown whether such decreased sensitivity to prospective losses represents a specific facet of altered decision-making or a secondary effect of executive/working-memory impairments. We addressed this issue by assessing whether lower loss aversion in 22 AUD patients compared with 19 healthy controls is explained by their differential executive or working-memory performance and by investigating its neural basis in terms of grey matter density and cortical thickness via voxel- and surface-based morphometry, respectively. A significant decrease of loss aversion in patients, unrelated to their impaired executive/working-memory performance, reflected the reduction of posterior fronto-medial grey matter density and right frontopolar cortical thickness. Rather than their executive deficits, patients' reduced loss aversion reflects the structural damage of the posterior fronto-medial cortex previously associated with solving conflicts at the response level, where earlier functional magnetic resonance imaging (fMRI) studies have shown a 'neural loss aversion' pattern of steeper deactivation for losses than activation for gains, and of the frontopolar cortex in charge of managing competing goals. These findings highlight possible directions for addressing AUD patients' high relapse rate, for example, cognitive-behavioural rehabilitative interventions enhancing the awareness of the adverse outcomes of addiction or neurostimulation protocols targeting the regions processing their salience.

Brain correlates of impaired goal management in bipolar mania.

Although executive impairment has been reported in mania, its brain functional correlates have been relatively little studied. This study examined goal management, believed to be more closely related to executive impairment in daily life than other executive tasks, using a novel functional magnetic resonance imaging (fMRI) paradigm in patients in this illness phase. Twenty-one currently manic patients with bipolar disorder and 30 matched healthy controls were scanned while performing the Computerized Multiple Elements Test (CMET). This requires participants to sequentially play four simple games, with transition between games being made either voluntarily (executive condition) or automatically (control condition). CMET performance was impaired in the manic patients compared to the healthy controls. Manic patients failed to increase activation in the lateral frontal, cingulate and inferior parietal cortex when the executive demands of the task increased, while this increase was observed in the healthy controls. Activity in these regions was associated with task performance. Manic patients show evidence of impaired goal management, which is associated with a pattern of reduced medial and lateral frontal and parietal activity.

Cognitive impairment burden in older and younger adults across the kidney transplant care continuum.

Younger kidney transplant (KT) candidates and recipients may have cognitive impairment due to chronic diseases and reliance on dialysis. To quantify cognitive impairment burden by age across the KT care continuum, we leveraged a two-center cohort study of 3854 KT candidates at evaluation, 1114 recipients at admission, and 405 recipients at 1-year post-KT with measured global cognitive performance (3MS) or executive function (Trail Making Test). We also estimated burden of severe cognitive impairment that affects functional dependence (activities of daily living [ADL]<6 or instrumental activities of daily living [IADL]<8). Among KT candidates, global cognitive impairment (18-34 years: 11.1%; 35-49 years: 14.0%; 50-64 years: 19.5%; ≥65 years: 22.0%) and severe cognitive impairment burden (18-34 years: 1.1%; 35-49 years: 3.0%; 50-64 years: 6.2%; ≥65 years: 7.7%) increased linearly with age. Among KT recipients at admission, global cognitive impairment (18-34 years: 9.1%; 35-49 years: 6.1%; 50-64 years: 9.3%; ≥65 years: 15.7%) and severe cognitive impairment burden (18-34 years: 1.4%; 35-49 years: 1.4%; 50-64 years: 2.2%; ≥65 years: 4.6%) was lower. Despite lowest burden of cognitive impairment among KT recipients at 1-year post-KT across all ages (18-34 years: 1.7%; 35-49 years: 3.4%; 50-64 years: 4.3%; ≥65 years: 6.5%), many still exhibited severe cognitive impairment (18-34 years: .0%; 35-49 years: 1.9%; 50-64 years: 2.4%; ≥65 years: 3.5%). Findings were consistent for executive function impairment. While cognitive impairment increases with age, younger KT candidates have a high burden comparable to community-dwelling older adults, with some potentially suffering from severe forms. Transplant centers should consider routinely screening patients during clinical care encounters regardless of age.

Early onset consumption of coca paste associated with executive-attention vulnerability markers linked to caudate-frontal structural and functional abnormalities

Coca paste is the most popular form of smoked cocaine (SC) in Latin America and also the most widespread among adolescents in vulnerable sectors of society, thus representing a significant public health concern. Despite evidence suggesting that abnormal executive-attention function is predictive of addiction to stimulant drugs, no study to date has compared clinically relevant neuropsychological (NPS) and physiological variables between individuals with histories of smoked cocaine dependence (SCD) and insufflated cocaine hydrochloride dependence (ICD). In this study we evaluated 25 SCD and 22 ICD subjects matched by poly-consumption profiles, and 25 healthy controls (CTR) matched by age, gender, education, and socioeconomic status. An exhaustive NPS battery was used to assess cognitive domains (attention, executive functions, fluid intelligence, memory, language and social cognition). We complemented this assessment with structural (MRI) and functional (fMRI) neuroimaging data. We found that executive function and attention impairments could be explained by the administration route of cocaine, with strongest impairments for the SCD group. SCD also presented reduced grey matter density relative to ICD and CTR in the bilateral caudate, a key area for executive and attentional function. Functional connectivity between left caudate and inferior frontal regions mediated the association between brain structure and behavioral performance. Our results highlight the relevance of assessing the route of administration of stimulants, both in clinical and research settings.

Can Tai Chi Improve Cognitive Function? A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Tai Chi (TC) is a traditional Chinese martial art with demonstrated beneficial effects on physical and mental health. In this study, the authors performed a systematic review to assess the efficiency of TC in different populations' cognitive function improvement. Design: The present systematic review utilized the Chinese National Knowledge Infrastructure (1915-), Wanfang (1998-), VIP (1989-), Chinese Biomedicine databases (1978-), PubMed (1950-), Web of Science (1900-), Cochrane Library (1948-), Embase (1974-), EBSCOhost (1922-), and OVID (1996-) databases to search and identify relevant articles published in English and Chinese from the beginning of coverage through October 17, 2020. Randomized controlled trials (RCTs) published from the beginning of coverage through October 17, 2020 in English and Chinese were retrieved from many indexing databases. Selected studies were graded according to the Cochrane Handbook for Systematic Reviews of Intervention 5.1.0. The outcome measures of cognitive function due to traditional TC intervention were obtained. Meta-analysis was conducted by using RevMan 5.4 software. We follow the PRISMA 2020 guidelines. Results: Thirty-three RCTs, with a total of 1808 participants, were included. The study showed that TC could progress global cognition when assessed in middle-aged as well as elderly patients suffering from cognitive and executive function impairment. The findings are as follows: Montreal Cognitive Assessment Scale: mean difference (MD) = 3.23, 95% CI = 1.88-4.58, p < 0.00001, Mini-Mental State Exam: MD = 3.69, 95% CI = 0.31-7.08, p = 0.03, Trail Making Test-Part B: MD = -13.69, 95% CI = -21.64 to -5.74, p = 0.0007. The memory function of older adults assessed by the Wechsler Memory Scale was as follows: MD = 23.32, 95% CI = 17.93-28.71, p < 0.00001. The executive function of college students evaluated by E-prime software through the Flanker test was as follows: MD = -16.32, 95% CI = -22.71 to -9.94, p < 0.00001. Conclusion: The TC might have a positive effect on the improvement of cognitive function in middle-aged and elderly people with cognitive impairment as well as older adults and college students.

A Novel Probable Pathogenic PSEN2 Mutation p.Phe369Ser Associated With Early-Onset Alzheimer's Disease in a Chinese Han Family: A Case Report

The pathogenesis of Alzheimer's disease is complex, and early-onset Alzheimer's disease (EOAD) is mostly influenced by genetic factors. Presenilin-1, presenilin-2 (PSEN2), and amyloid precursor protein are currently known as the three main causative genes for autosomal dominant EOAD, with the PSEN2 mutation being the rarest. In this study, we reported a 56-year-old Chinese Han proband who presented with prominent progressive amnesia, aphasia, executive function impairment, and depression 5 years ago. The 3-year follow-up showed that the patient experienced progressive brain atrophy displayed on magnetic resonance imaging (MRI) and dramatic cognitive decline assessed by neuropsychological evaluation. This patient was clinically diagnosed as EOAD based on established criteria. A heterozygous variant (NM_000447.2: c.1106T>C) of PSEN2 was identified for the first time in this patient and her two daughters. This mutation causing a novel missense mutation (p.Phe369Ser) in transmembrane domain 7 encoded by exon 11 had not been reported previously in 1000Genomes, ExAC, or ClinVar databases. This mutation was predicted by four in silico prediction programs, which all strongly suggested that it was damaging. Our results suggest that this novel PSEN2 Phe369Ser mutation may alter PSEN2 protein function and associate with EOAD.