Xinyi Cao

Effects of Cognitive Training on Resting-State Functional Connectivity of Default Mode, Salience, and Central Executive Networks.

Neuroimaging studies have documented that aging can disrupt certain higher cognitive systems such as the default mode network (DMN), the salience network and the central executive network (CEN). The effect of cognitive training on higher cognitive systems remains unclear. This study used a 1-year longitudinal design to explore the cognitive training effect on three higher cognitive networks in healthy older adults. The community-living healthy older adults were divided into two groups: the multi-domain cognitive training group (24 sessions of cognitive training over a 3-months period) and the wait-list control group. All subjects underwent cognitive measurements and resting-state functional magnetic resonance imaging scanning at baseline and at 1 year after the training ended. We examined training-related changes in functional connectivity (FC) within and between three networks. Compared with the baseline, we observed maintained or increased FC within all three networks after training. The scans after training also showed maintained anti-correlation of FC between the DMN and CEN compared to the baseline. These findings demonstrated that cognitive training maintained or improved the functional integration within networks and the coupling between the DMN and CEN in older adults. Our findings suggested that multi-domain cognitive training can mitigate the aging-related dysfunction of higher cognitive networks.

Efficacy and safety of treating patients with refractory schizophrenia with antipsychotic medication and adjunctive electroconvulsive therapy: a systematic review and meta-analysis.

Background The efficacy and safety of the combined treatment of refractory schizophrenia with antipsychotic medications and electroconvulsive therapy (ECT) remain uncertain. Aims Conduct systematic review and meta-analysis of available literature in English and Chinese about ECT in the treatment of refractory schizophrenia. Methods English and Chinese databases were searched for studies published prior to May 20, 2015 regarding the efficacy and safety of the combined treatment of refractory schizophrenia with antipsychotic medications and ECT. Two researchers selected and evaluated studies independently using pre-defined criteria. Review Manager 5.3 software was used for data analysis. Results A total of 22 randomized control studies, 18 of which were conducted in mainland China, were included in the analysis. Meta-analysis of data from 18 of the 22 studies with a pooled sample of 1394 individuals found that compared to treatment with antipsychotic medications alone, combined treatment with antipsychotic medications and ECT had significantly higher rates of achieving study-specific criteria of ‘clinical improvement’ (RR=1.25, 95%CI=1.14-1.37). Based on the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria, the quality of evidence for this assessment of efficacy was ‘moderate’. However, the proportion of participants who experienced headache during the treatment was significantly higher in the combined treatment group (RR=9.10, 95%CI=3.97-20.86, based on a pooled sample of 517 from 8 studies) and the proportion who experienced memory impairment was also higher in the combined treatment group (RR=6.48, 95%CI=3.54-11.87, based on a pooled sample of 577 from 7 studies). The quality of evidence about these adverse events was rated as ‘very low’. Conclusions There are very few high quality randomized controlled clinical trials about the combination of antipsychotic medications and ECT in the treatment of refractory schizophrenia. This meta-analysis found that the combination of antipsychotic medications and ECT could improve psychiatric symptoms in patients with refractory schizophrenia, but the incomplete methodological information provided for most of the studies, publication bias (favoring studies with better outcomes in the combined treatment group), and the low quality of evidence about adverse outcomes, cognitive impairment, and overall functioning raise questions about the validity of the results.

The Lateralization of Intrinsic Networks in the Aging Brain Implicates the Effects of Cognitive Training

Lateralization of function is an important organization of the human brain. The distribution of intrinsic networks in the resting brain is strongly related to cognitive function, gender and age. In this study, a longitudinal design with 1 year’s duration was used to evaluate the cognitive training effects on the lateralization of intrinsic networks among healthy older adults. The subjects were divided into two groups randomly: one with multi-domain cognitive training over 3 months and the other as a wait-list control group. Resting state fMRI data were acquired before training and 1 year after training. We analyzed the functional lateralization in 10 common resting state fMRI networks. We observed statically significant training effects on the lateralization of two important RSNs related to high-level cognition: right- and left- frontoparietal networks (FPNs). The lateralization of the left-FPN was retained especially well in the training group but decreased in the control group. The increased lateralization with aging was observed in the cerebellum network (CereN), in which the lateralization was significantly increased in the control group, although the same change tendency was observed in the training group. These findings indicate that the lateralization of the high-level cognitive intrinsic networks is sensitive to multi-domain cognitive training. This study provides neuroimaging evidence to support the hypothesis that cognitive training should have an advantage in preventing cognitive decline in healthy older adults.

The Impact of Cognitive Training on Cerebral White Matter in Community-Dwelling Elderly: One-Year Prospective Longitudinal Diffusion Tensor Imaging Study.

It has been shown that cognitive training (CogTr) is effective and recuperative for older adults, and can be used to fight against cognitive decline. In this study, we investigated whether behavioural gains from CogTr would extend to white matter (WM) microstructure, and whether training-induced changes in WM integrity would be associated with improvements in cognitive function, using diffusion tensor imaging (DTI). 48 healthy community elderly were either assigned to multi-domain or single-domain CogTr groups to receive 24 sessions over 12 weeks, or to a control group. DTI was performed at both baseline and 12-month follow-up. Positive effects of multi-domain CogTr on long-term changes in DTI indices were found in posterior parietal WM. Participants in the multi-domain group showed a trend of long-term decrease in axial diffusivity (AD) without significant change in fractional anisotropy (FA), mean diffusivity (MD) or radial diffusivity (RD), while those in the control group displayed a significant FA decrease, and an increase in MD and RD. In addition, significant relationships between an improvement in processing speed and changes in RD, MD and AD were found in the multi-domain group. These findings support the hypothesis that plasticity of WM can be modified by CogTr, even in late adulthood.

Amyloid Plaques in Retina for Diagnosis in Alzheimer's Patients: a Meta-Analysis

Background: Detection of retinal β-amyloid (Aβ) peptide accumulation is a novel diagnostic method for Alzheimer’s disease (AD), but there is, as yet, no conclusive evidence of its accuracy. Aim: To identify the diagnostic accuracy of pathological retinal Aβ detection for AD by a meta-analytic approach. Methods: Electronic and reference searches were conducted to identify studies related to the diagnostic effects of retinal Aβ detection in AD that met pre-defined inclusion criteria. The QUADAS-2 tool was employed to assess the risk of bias, and Review Manager plus the Open Meta-Analyst were used to perform the data analysis. Results: From 493 unduplicated reports, five studies with small sample sizes were included in this review. Six staining methods were employed. The eligible studies showed extremely broad ranges of sensitivity (0–1.00) and specificity (0.50–1.00) with substantial heterogeneity. The estimates of positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) were also extremely varied (from 0.71 to 11.57 for PLR, from 0.04 to 1.11 for NLR, and from 0.69 to 297.00 for DOR). Conclusions: The limited number of eligible studies and their methodological heterogeneity make it impossible to come to a conclusion whether pathological retinal Aβ detection is an effective diagnostic tool for AD. More studies, especially large surveys investigating retina Aβ load with quantitative methods among consecutive or random samples, are needed to determine the accuracy of Aβ detection for diagnosing AD.

Cortical Thickness Changes Correlate with Cognition Changes after Cognitive Training: Evidence from a Chinese Community Study

The aim of this study was to investigate whether changes in cortical thickness correlated with cognitive function changes in healthy older adults after receiving cognitive training interventions. Moreover, it also aimed to examine the differential impacts of a multi-domain and a single-domain cognitive training interventions. Longitudinal magnetic resonance imaging (MRI) scanning was performed on participants 65–75 years of age using the Siemens 3.0 T Trio Tim with the Magnetization Prepared Rapid Gradient Echo (MPRAGE) sequence. The cortical thickness was determined using FreeSurfer Software. Cognitive functioning was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). There were significant group × time interaction effects on the left supramarginal, the left frontal pole cortical regions; and a marginal significant group × time interaction effects on visuospatial/constructional and delayed memory scores. In a multi-domain cognitive training group, a number of cortical region changes were significantly positively correlated with changes in attention, delayed memory, and the total score, but significantly negatively correlated with changes in immediate memory and language scores. In the single-domain cognitive training group, some cortical region changes were significantly positively associated with changes in immediate memory, delayed memory, and the total score, while they were significantly negatively associated with changes in visuospatial/constructional, language, and attention scores. Overall, multi-domain cognitive training offered more advantages in visuospatial/constructional, attention, and delayed memory abilities, while single-domain cognitive training benefited immediate memory ability more effectively. These findings suggest that healthy older adults benefit more from the multi-domain cognitive training than single-domain cognitive training. Cognitive training has impacted on cortical thickness changes in healthy elderly.

Cross-sectional study of the association of cognitive function and hippocampal volume among healthy elderly adults

Background Cognitive impairment and dementia among elderly adults is a pressing public health issue in China but research on biomarkers of cognitive decline has been limited. Aim Explore the relationship between multiple domains of cognitive functioning and the volume of the left and right hippocampus in healthy elderly adults. Methods Structural MRI scanning was performed on 65 community-dwelling healthy participants 65 to 75 years of age using the Siemens 3.0 T Trio Tim with the MPRAGE sequence. The volumes of the left and right hippocampus were determined using Freesurfer software. Cognitive functioning was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Both unadjusted and adjusted associations between the hippocampal volumes and cognitive functioning were estimated. Results Within this relatively narrow age range, age was significantly associated with most of the cognitive measures assessed in women but was not significantly associated with any of the cognitive measures in men. In both men and women right hippocampal volume was positively associated with delayed memory and left hippocampal volume was positively associated with both immediate memory and delayed memory (though the relationship with delayed memory in women was only at a trend level). After adjustment for age, gender, and years of formal education (the variable that was most strongly associated with all of the cognitive measures), both left hippocampal volume and right hippocampal volume were positively associated with delayed memory, but not with immediate memory. Interestingly, the difference in the volumes of the left and right hippocampi was negatively associated with the score of the RBANS attention subscale, a relationship that was stronger in women than in men. Conclusions This study confirms previous work about the relationship of hippocampal volume and memory, identifies a possible relationship between attention and the difference in size of the two hippocampi, and suggests that there may be some differences in these relationships by gender.

25 Hz Magnetic Seizure Therapy is Feasible but Not Optimal for Chinese Patients with Schizophrenia: A case series

Magnetic seizure therapy (MST) is a potential alternative to electroconvulsive therapy (ECT), but there is currently a lack of reports about MST in Chinese patients with schizophrenia. Our objective was to investigate the feasibility and acceptability of add-on MST in the treatment of patients with schizophrenia. Eight patients with schizophrenia were enrolled in a case series study to receive 10 sessions of add-on MST over 4 weeks. The MST was administrated using 25 Hz at 100% output with a titration duration ranging from 4 to 20 s by 4 s. The Positive and Negative Syndrome Scale (PANSS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were employed to measure the symptom improvements and the cognitive effects, respectively. Six patients completed at least one-half of the planned sessions. Five showed a reduction in PANSS total score, and three achieved clinical response (≥30% reduction). Three of the participants receiving the RBANS, showed either improvements or no changes in the memory function. Regarding the subjective complaints about MST, two reported dizziness, and only one reported memory loss. Approximately one-fourth of the treatment sessions produced only brief seizures (<15 s). Overall, employing MST to treat Chinese patients with schizophrenia appeared feasible and acceptable. However, further evidence is needed to determine the therapeutic efficacy and effects of MST on the cognitive functions of patients with schizophrenia.

The Moderating Role of COMT and BDNF Polymorphisms on Transfer Effects Following Multi- and Single-Domain Cognitive Training Among Community-Dwelling Shanghainese Older Adults

Given the increase in research suggesting benefit following cognitive training in older adults, researchers have started to investigate the potential moderating role of genetic polymorphisms on transfer effects. The objective of this study was to evaluate the moderating effect of catechol-O-methyltransferase (COMT) and brain-derived neurotrophic factor (BDNF) polymorphisms on transfer effects following a single-domain or multi-domain training intervention in healthy community-dwelling older adults. A total of 104 men and women living in Shanghai were randomized to a multi-domain or a single-domain cognitive training (SDCT) group. COMT rs4818 SNP and the BDNF rs6265 SNP were analyzed from blood. At pre-intervention, post-intervention and at 6-month follow-up, participants completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the Color-Word Stroop Test (CWST), the Trails Making Test (TMT) and the Visual Reasoning Test (VRT). COMT was found to moderate immediate memory transfer effects following single-domain training only, with G/- carriers displaying greater benefits than C/C carriers. BDNF was found to moderate attention and inhibition independent of the training, with Met/- carriers displaying better performance than Val/Val carriers. Overall, individualizing training methods with full consideration of genetic polymorphisms may promote the maximization of cognitive training benefits.

Magnetic seizure therapy for people with schizophrenia

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To estimate the effects of magnetic seizure therapy (MST) alone compared with sham MST or with standard care or any other comparators for schizophrenia.