Normative Data Estimation in Neuropsychological Tests: A Systematic Review

OBJECTIVE

To quantify the evolution, impact, and importance of normative data (ND) calculation by identifying trends in the research literature and what approaches need improvement.

METHODS

A PRISMA-guideline systematic review was performed on literature from 2000 to 2022 in PubMed, Pub-Psych, and Web of Science. Inclusion criteria included scientific articles about ND in neuropsychological tests with clear data analysis, published in any country, and written in English or Spanish. Cross-sectional and longitudinal studies were included. Bibliometric analysis was used to examine the growth, productivity, journal dispersion, and impact of the topic. VOSViewer compared keyword co-occurrence networks between 1952-1999 and 2000-2022.

RESULTS

Four hundred twelve articles met inclusion and exclusion criteria. The most studied predictors were age, education, and sex. There were a greater number of studies/projects focusing on adults than children. The Verbal Fluency Test (12.7%) was the most studied test, and the most frequently used variable selection strategy was linear regression (49.5%). Regression-based approaches were widely used, whereas the traditional approach was still used. ND were presented mostly in percentiles (44.2%). Bibliometrics showed exponential growth in publications. Three journals (2.41%) were in the Core Zone. VOSViewer results showed small nodes, long distances, and four ND-related topics from 1952 to 1999, and there were larger nodes with short connections from 2000 to 2022, indicating topic spread.

CONCLUSIONS

Future studies should be conducted on children's ND, and alternative statistical methods should be used over the widely used regression approaches to address limitations and support growth of the field.

Reduced skeletal muscle mass to visceral fat area ratio is independently associated with reduced cognitive function in type 2 diabetes mellitus

AIM

Skeletal muscle mass to visceral fat area ratio (SVR) has been recognised as an index of sarcopenic obesity. SVR is associated with type 2 diabetes mellitus (T2DM), metabolic syndrome and arterial stiffness which are known risk factors for cognitive dysfunction. We aimed to investigate association between SVR and cognitive function in patients with T2DM.

METHODS

This was a cross-sectional study of 1326 patients with T2DM and mean age 61.3 ± 8.0 years. SVR was assessed based on bioelectrical impedance measurements of muscle mass and visceral fat area (VFA). Cognitive function was assessed using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Linear regression was used to examine the association between SVR in quartiles and RBANS score, adjusting for demographics, education, presence of depressive symptoms, clinical covariates and medications.

RESULTS

The lower SVR quartiles were negatively associated with RBANS total score in the unadjusted analysis. The corresponding coefficients for Quartiles 1 and 2 SVR were -3.79 (95 % CI -5.39 to -2.19; p < 0.001) and -1.47 (95 % CI -2.86 to -0.07; p = 0.039) in fully adjusted analysis. The negative association between Quartile 1 SVR and RBANS score was evident in immediate memory, delayed memory, visuo-spatial construction, language and attention domains. Muscle mass and VFA alone had weaker associations with RBANS scores.

CONCLUSION

Our study demonstrated, for the first time, an independent association between reduced SVR and lower cognitive function. This is evident in global and multiple cognitive domains. The synergistic effects of reduced muscle mass and visceral obesity may be more pronounced than their independent effects on cognitive function.

Content development of the VISION-Cog: a novel tool to assess cognitive impairment in visually impaired older adults in Singapore

OBJECTIVES

Current cognitive screening and diagnostic instruments rely on visually dependent tasks and are, therefore, not suitable to assess cognitive impairment (CI) in visually impaired older adults. We describe the content development of the VISually Independent test battery Of NeuroCOGnition (VISION-Cog)-a new diagnostic tool to evaluate CI in visually impaired older Singaporean adults.

DESIGN

The content development phase consisted of two iterative stages: a neuropsychological consultation and literature review (stage 1) and an expert-panel discussion (stage 2). In stage 1, we investigated currently available neuropsychological test batteries for CI to inform constructions of our preliminary test battery. We then deliberated this battery during a consensus meeting using the Modified Nominal Group technique (stage 2) to decide, via agreement of five experts, the content of a pilot neuropsychological battery for the visually impaired.

SETTING

Singapore Eye Research Institute.

PARTICIPANTS

Stakeholders included researchers, psychologists, neurologists, neuro-ophthalmologists, geriatricians and psychiatrists.

OUTCOME MEASURE

pilot VISION-Cog.

RESULTS

The two-stage process resulted in a pilot VISION-Cog consisting of nine vision-independent neuropsychological tests, including the modified spatial memory test, list learning, list recall and list recognition, adapted token test, semantic fluency, modified spatial analysis, verbal subtests of the frontal battery assessment, digit symbol, digit span forwards, and digit span backwards. These tests encompassed five cognitive domains-memory and learning, language, executive function, complex attention, and perceptual-motor abilities. The expert panel suggested improvements to the clarity of test instructions and culturally relevant test content. These suggestions were incorporated and iteratively pilot-tested by the study team until no further issues emerged.

CONCLUSIONS

We have developed a five-domain and nine-test VISION-Cog pilot instrument capable of replacing vision-dependent diagnostic batteries in aiding the clinician-based diagnosis of CI in visually impaired older adults. Subsequent phases will examine the VISION-Cog's feasibility, comprehensibility and acceptability; and evaluate its diagnostic performance.

Feasibility, comprehensibility and acceptability of the VISION-Cog, a novel tool to assess cognitive impairment in visually impaired older adults: a cross-sectional pilot study in Singapore

OBJECTIVES

We pilot-tested the VISually Independent test battery Of NeuroCOGnition (VISION-Cog) to determine its feasibility, comprehensibility and acceptability in evaluating cognitive impairment (CI) in visually impaired older Asian adults.

DESIGN

The VISION-Cog was iteratively fine-tuned through pilot studies and expert-panel discussion. In the first pilot study (Stage 1), we recruited 15 visually impaired and cognitively normal participants aged ≥60 years to examine the pilot VISION-Cog's feasibility (length of time to administer), comprehensibility (clarity of instructions) and acceptability (participant burden). We then presented the pilot results to the expert panel (Stage 2) who decided via agreement on a revised version of the VISION-Cog. Subsequently, we conducted a second pilot study (Stage 3) on another four participants to ascertain improvement in feasibility, comprehensibility and acceptability of the revised version.

SETTING

Singapore Eye Research Institute.

PARTICIPANTS

Nineteen Asian adults aged ≥60 years with visual impairment (defined as near visual acuity worse than N8) were recruited.

OUTCOME MEASURE

Revised VISION-Cog.

RESULT

The VISION-Cog was deemed feasible, taking approximately 60 min to complete on average. All participants agreed that the test instructions were clear, and the battery did not cause undue discomfort or frustration. The data collector rated all tests as very user-friendly (score of 5/5). Minor modifications to the pilot VISION-Cog were suggested by the panel to improve its safety, clarity of instructions and content validity, which were incorporated and iteratively tested in the second pilot study until no further issues emerged.

CONCLUSIONS

Using an iterative mixed-methods process, we have developed a feasible, comprehensible and acceptable 5-domain and 9-item visually independent VISION-Cog test battery suitable to assist CI diagnosis in older adults with visual impairment. We will assess its diagnostic potential against clinician-based assessment of CI in subsequent phases.

Decline in skeletal muscle mass is associated with cognitive decline in type 2 diabetes mellitus

AIMS

To examine the longitudinal association between skeletal muscle mass (SMM) loss and cognitive decline over time in type 2 diabetes mellitus (T2DM).

METHODS

We conducted a prospective cohort study of 453 patients from SMART2D cohort with follow-up intervals of 1.6 to 6.4 years. Baseline and follow-up measurements included bio-impedance analysis (BIA) measure of skeletal muscle mass index (SMI) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) measure of cognitive function. We examined the association between annual rate of SMI and RBANS scores using linear regression, adjusting for demographics, education, depression, clinical co-variables and presence of apolipoprotein E4 (APOE) _Ɛ4 allele.

RESULTS

The mean age of participants was 60.3 ± 7.4 years. Compared to patients with Tertile 1 SMI change, the group with greater SMI decline (Tertile 3 SMI change) experienced 0.30 decline in RBANS total score (95%CI -0.57 to -0.03; p = 0.030) in the adjusted analysis. RBANS scores for subdomains in immediate memory and visuo-spatial/construction were lower in Tertile 3 SMI change group with corresponding coefficients -0.54 (95%CI -1.01 to -0.06; p = 0.026), and -0.71 (95%CI -1.30 to -0.12; p = 0.019) respectively.

CONCLUSION

In patients with T2DM, BIA measure of muscle mass loss over time was independently associated with cognitive decline globally and in the domains of memory and visuo-spatial/construction.

Enhanced gait variability index and cognitive performance in Asian adults: Results from the Yishun Study

BACKGROUND

Although gait variability has been linked to cognitive decline among older adults, the lack of a comprehensive composite gait variability score has dampened the application of gait variability.

RESEARCH QUESTION

Does the enhanced gait variability index (EGVI) - a composite score gait variability index - provide differential and useful information on cognitive decline in community-dwelling adults from that using gait speed?

METHODS

Healthy community-dwelling adults (n = 311) aged 21-90 were individually administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Habitual gait speed and spatiotemporal parameters were measured using a 6 m instrumented walkway system. The EGVI for each participant was calculated from five spatiotemporal parameters - step length(cm), step time(s), stance time(s), single support time(s) and stride velocity(cm/s). Linear regression models, controlling for age, gender, and education, were built to examine the independent effects of EGVI or gait speed on global cognition and individual domains.

RESULTS

Multiple regression revealed that gait speed contributed significantly to the performance of the domain "Attention" (p = 0.04) whereas EGVI contributed significantly for the performance of the domain "Visuospatial" (p = 0.04) and "Delayed Memory" (p = 0.02).

SIGNIFICANCE

EGVI provides differential and useful information from using gait speed alone. The EGVI may offer a solution to measure or track GV changes in relation to cognitive changes.

Associations of low handgrip strength and hand laterality with cognitive function and functional mobility - the Yishun Study

Background

Emerging evidence suggest that in addition to low hand grip strength (HGS), HGS asymmetry is associated with declining cognitive and physical functions. We examined the associations of low HGS and asymmetry with cognitive function and functional mobility in older adults.

Methods

Cross-sectional data of 330 community-dwelling adults (55.2% women) aged ≥ 55 years included HGS, Repeated Battery for the Assessment of Neuropsychological Status (RBANS), and Timed-Up-and-Go (TUG). Low HGS was defined as < 28 kg for men and < 18 kg for women. Participants with HGS above 10% stronger on either hand were considered as having HGS asymmetry. Multiple linear regression models were adjusted for sociodemographic, smoking, education, comorbidity count, physical activity participation, obesity, self-rated health and hand dominance.

Results

Low HGS, but not asymmetry, was independently associated with lower functional mobility performance (β = 1.3, 95%CI = 0.6,1.9), global cognitive function (β = -10.4, 95%CI = -17.0,-3.8), immediate (β = -2.6, 95%CI = -4.5,-0.7) and delayed (β = -2.8, 95%CI = -5.0,-0.7) memory. Compared to normal and symmetric HGS participants, low HGS in combination with HGS asymmetry was associated with poorer language scores. In participants with normal HGS, asymmetric HGS was associated with slower TUG than corresponding groups with symmetric HGS.

Conclusion

Low HGS, but not asymmetry, was associated with lower cognition and functional mobility. Associations of combined low HGS and asymmetry with cognitive and physical functions were driven by grip strength rather than asymmetry.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03363-2.

Association of early-onset Type 2 diabetes with cognitive impairment is partially mediated by increased pulse pressure

AIMS

Type 2 diabetes mellitus (T2DM) has been shown to be associated with cognitive decline and dementia. As earlier onset of diabetes implies a longer disease duration and an increased risk to complications, we sought to investigate the effect of T2DM onset on cognitive function of our patients.

METHODS

We administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to T2DM patients aged 45-85 from our SMART2D cohort. We assessed the association of the T2DM onset age (both continuous and stratified into 3 groups: early-onset ≤40 (n = 326), middle-aged onset 41-64 (n = 703) and late-onset ≥65 years old (n = 38)) and RBANS cognitive indices in 1067 patients. Potential mediation of this association by vascular compliance using mediation analysis was investigated.

RESULTS

T2DM onset associates significantly with RBANS total score. Patients with early T2DM onset have lower RBANS total score as compared to patients with middle-aged onset (β = -2.01, p = 0.0102) and those with late-onset (β = -5.80, p = 0.005). This association was partially mediated by pulse pressure index (25.8%), with indirect effect of 0.028 (Bootstrapped-CI: 0.008-0.047).

CONCLUSIONS

Association of early-onset T2DM with cognitive impairment is partly mediated by diminished vascular compliance. Appropriate screening and assessment of cognitive function is important for early intervention and management of cognitive impairment.

Ethnic-Specific Type 2 Diabetes Risk Factor PAX4 R192H Is Associated with Attention-Specific Cognitive Impairment in Chinese with Type 2 Diabetes

Background: Type 2 diabetes mellitus (T2DM) has been shown to increase the risks of cognitive decline and dementia. Paired box gene 4 (PAX4), a transcription factor for beta cell development and function, has recently been implicated in pathways intersecting Alzheimer’s disease and T2DM. Objective: In this report, we evaluated the association of the ethnic-specific PAX4 R192H variant, a T2DM risk factor for East Asians which contributes to earlier diabetes onset, and cognitive function of Chinese T2DM patients. Methods: 590 Chinese patients aged 45–86 from the SMART2D study were genotyped for PAX4 R192H variation using Illumina OmniExpress-24 Array. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) which had been validated in the Singapore population was administered to assess five cognitive domains: immediate memory, visuospatial/constructional, language, attention, and delayed memory. Multiple linear regression was used to assess the association of the R192H risk allele and cognitive domains. Results: Patients with two PAX4 R192H risk alleles showed significantly lower attention index score (β= –8.46, 95% CI [–13.71, –3.21], p = 0.002) than patients with wild-type alleles after adjusting for age, gender, diabetes onset age, HbA1c, body-mass index, renal function, lipid profiles, systolic blood pressure, metformin usage, smoking history, education level, Geriatric Depression Scale score, and presence of APOE ɛ4 allele. Conclusion: Ethnic-specific R192H variation in PAX4 is associated with attention-specific cognitive impairment in Chinese with T2DM. Pending further validation studies, determining PAX4 R192H genotype may be helpful for early risk assessment of early-onset T2DM and cognitive impairment to improve diabetes care.

Normative Data for Adult Mandarin-Speaking Populations: A Systematic Review of Performance-Based Neuropsychological Instruments

OBJECTIVES

Normative data are essential for neuropsychological evaluations, but they are scarce for Mandarin-speaking populations, despite Mandarin being the language with the most native speakers. Several normative data studies have been reported in recent years for Mandarin speakers, who reside in different countries/regions (e.g., mainland China, Taiwan, and Singapore, etc.). This review aims to serve as a reference guide to appropriate norms when working with a Mandarin-speaking patient and to guide future endeavors in test validation and development in areas where studies to date fall short.

METHOD

We conducted a systematic review utilizing the PsycInfo, PubMed, and China Knowledge Resource Integrated databases as well as additional literature search through citations. We performed evaluations of the existing norms based on their test selection, cognitive domains covered, sample size, language, regions of participant recruitment, stratification by age/gender/education levels, and reporting of other psychometric properties. We focused on articles that included performance-based tests for adults but excluded those with purely clinical norms or from commercial publishers.

RESULTS

We reviewed 1155 articles found through literature search and identified 43 articles reporting normative data for this population that met our inclusion criteria. Sixty-five distinctive tests and 127 versions were covered. The results are presented within two detailed tables organized by articles and tests, respectively.

CONCLUSIONS

We discussed the strengths and limitations of these normative reports. Practitioners are recommended to utilize normative data that most closely approximate a test-taker's cultural and demographic backgrounds. Limitations of the current review are also discussed.

Evaluation of the Implementation and Effectiveness of Community-Based Brain-Computer Interface Cognitive Group Training in Healthy Community-Dwelling Older Adults: Randomized Controlled Implementation Trial

BACKGROUND

Cognitive training can improve cognition in healthy older adults.

OBJECTIVE

The objectives are to evaluate the implementation of community-based computerized cognitive training (CCT) and its effectiveness on cognition, gait, and balance in healthy older adults.

METHODS

A single-blind randomized controlled trial with baseline and follow-up assessments was conducted at two community centers in Singapore. Healthy community-dwelling adults aged 55 years and older participated in a 10-week CCT program with 2-hour instructor-led group classes twice a week. Participants used a mobile app to play games targeting attention, memory, decision making, visuospatial abilities, and cognitive flexibility. Implementation was assessed at the participant, provider, and community level (eg, reach, implementation, and facilitators and barriers). Effectiveness measures were the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Color Trails Test 2 (CTT-2), Berg Balance Scale, and GAITRite walkway measures (single and dual task gait speed, dual task cost, and single and dual task gait variability index [GVI]).

RESULTS

A total of 94 healthy community-dwelling adults participated in the CCT program (mean age 68.8 [SD 6.3] years). Implementation measures revealed high reach (125/155, 80.6%) and moderate adherence but poor penetration of sedentary older adults (43/125, 34.4%). The effectiveness data were based on intention-to-treat (ITT) and per-protocol (PP) analysis. In the ITT analysis, single task GVI increased (b=2.32, P=.02, 95% CI [0.30 to 4.35]) and RBANS list recognition subtest deteriorated (b=-0.57, P=.01, 95% CI [-1.00 to -0.14]) in both groups. In the PP analysis, time taken to complete CTT-2 (b=-13.5, P=.01, 95% CI [-23.95 to -3.14]; Cohen d effect size = 0.285) was faster in the intervention group. Single task gait speed was not statistically significantly maintained in the intervention group (b=5.38, P=.06, 95% CI [-0.30 to 11.36]) and declined in the control group (Cohen d effect size = 0.414). PP analyses also showed interaction terms for RBANS list recall subtest (b=-0.36, P=.08, 95% CI [-0.75 to 0.04]) and visuospatial domain (b=0.46, P=.08, 95% CI [-0.05 to 0.96]) that were not statistically significant.

CONCLUSIONS

CCT can be implemented in community settings to improve attention and executive function among healthy older adults. Findings help to identify suitable healthy aging programs that can be implemented on a larger scale within communities.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04439591; https://clinicaltrials.gov/ct2/show/NCT04439591.

Coexistence of osteoporosis, sarcopenia and obesity in community-dwelling adults - The Yishun Study

OBJECTIVES

To 1) report prevalence of 'osteosarcopenia' (OS) and osteosarcopenic obesity (OSO) entities using evidence-based diagnostic techniques and definitions, 2) examine if OSO offers additional predictive value of functional decline over its components, and 3) identify associated factors in a multi-racial Southeast Asian population.

METHODS

We performed a cross-sectional study of a representative sample of 542 community-dwelling adults (21-90 years old), and assessed anthropometry, cognition, functional performance, and self-report sociodemographic, health and lifestyle questionnaires. Low muscle mass, and the Asian Working Group for Sarcopenia (AWGS) 2019 criteria, were used to assess sarcopenia. Obesity was defined using percentage body fat and fat mass index. Osteopenia/osteoporosis was determined using lumbar spinal bone mineral density. Associated factors were examined using logistic regression, and OSO's value investigated using linear regressions with functional performance.

RESULTS

OS and OSO prevalence were 1.8% and 0% (21-59 years), 12.9% and 2.8% (≥ 60 years), 17.3% and 4.1% (≥ 65 years), and 25.5% and 7.0% (≥75 years), respectively. OSO entity as defined was not a significant predictor (P > 0.05) and did not improve explanations for functional decline over sarcopenia or sarcopenic obesity. Age, sex, race and body mass index (BMI) were associated with OS, while age, sex, race and alcoholism were associated with OSO.

CONCLUSIONS

Our results do not support OSO as a distinct entity in relation to functional decline. Aside from biological age, sex, and race, amenable lifestyle factors such as BMI and alcohol intake are important variables that can influence the co-existence of osteopenia/osteoporosis, sarcopenia and obesity.

Malnutrition and Sarcopenia in Community-Dwelling Adults in Singapore: Yishun Health Study

OBJECTIVES

To determine the overlapping prevalence of malnutrition and sarcopenia and the association between parameters of malnutrition with muscle mass and strength in a community-dwelling Singaporean adult population.

DESIGN

This was a cross-sectional study.

SETTING

Large north-eastern residential town of Yishun in Singapore.

PARTICIPANTS

Random sampling of community-dwelling Singaporeans aged 21-90 years old (n=541).

MEASUREMENTS

Anthropometry, body composition and handgrip strength (muscle strength) were measured. Sarcopenia was identified using dual-energy x-ray absorptiometry scan (muscle mass). Nutritional status was measured using Mini Nutritional Assessment (MNA-SF). Other questionnaires collected included physical activity and cognition. Associations between nutritional status with sarcopenia as well as with muscle mass and strength were analysed using multinomial logistics and linear regressions.

RESULTS

The overall population-adjusted prevalence of those at nutritional risk and malnourished were 18.5% and 0.1% respectively. More than a third of participants (35%) who were at nutritional risk were sarcopenic. Malnourished participants were all sarcopenic (100%, N=2) whereas those who were sarcopenic, 27.0% (N=37) were at nutritional risk/malnourished. Being at nutritional risk/malnourished was significantly associated with 2 to 3 times increased odds of sarcopenia in multivariate analyses adjusting for age, gender, physical activity level and cognition, and fat mass index. Favourable MNA parameter scores on food intake and BMI were positively associated with greater muscle mass and handgrip strength (p<0.05).

CONCLUSION

Given the overlapping clinical presentation of malnutrition and sarcopenia, community screening protocols should include combination screening of nutritional status and sarcopenia with appropriate interventions to mitigate risk of adverse health outcomes.

Prevalence and Associated Factors of Sarcopenia in Singaporean Adults-The Yishun Study

OBJECTIVES

To describe the normative values of sarcopenia among community-dwelling adults (≥21 years of age); compare the prevalence of sarcopenia using Asian Working Group for Sarcopenia criteria, 2014 (AWGS2014), Asian Working Group for Sarcopenia criteria, 2019 (AWGS2019), and European Working Group on Sarcopenia in Older People criteria, 2018 (EWGSOP2) guidelines; and identify factors associated with sarcopenia.

DESIGN

Participants were recruited through random sampling. Sarcopenia assessments were performed using a dual-energy x-ray absorptiometry scan (muscle mass), handgrip test (muscle strength), and usual walking test (physical performance). Questionnaires were administered to evaluate lifestyle and cognition.

SETTING AND PARTICIPANTS

In total, 542 community-dwelling Singaporeans were recruited (21‒90 years old, 57.9% women).

METHODS

We assessed anthropometry, body composition, and questionnaire-based physical and cognitive factors, and estimated sarcopenia prevalence according to the AWGS2014, AWGS2019, and EWGSOP2 recommendations, and examined associations using logistic regression.

RESULTS

According to AWGS2019, the Singapore population-adjusted sarcopenia prevalence was 13.6% (men 13.0%; women 14.2%) overall, and 32.2% (men 33.7%, women 30.9%) in those aged 60 years and above. The cut-offs derived from young adult reference group for low appendicular lean mass index were 5.28 kg/m2 for men and 3.69 kg/m2 for women (lower than AWGS recommended cut-off); for gait speed it was 0.82 m/s, (AWGS2019 recommended cut-off 1.0 m/s, AWGS2014 cut-off was 0.8 m/s); and for handgrip strength it was 27.9 kg/m2 for men and 16.7 kg/m2 for women (close to AWGS2019 recommendation). Age, sex, marital status, alcoholism, physical activity, body mass index, waist circumference, and global cognition were associated with sarcopenia (P < .05).

CONCLUSIONS AND IMPLICATIONS

This is the first study to provide reference values of muscle mass, strength, and gait speed across the adult lifespan of Singaporeans. Using AWGS2019 criteria, sarcopenia is prominent in older age (32.2% in ≥60 years old), but it is already nontrivial (6.9%) among young and middle-age persons. Multidomain lifestyle modifications addressing muscle strength, cognition, and nutrition over the adult lifespan are important to delay the development of sarcopenia.

Cognitive decline on the Repeatable Battery for the Assessment of Neuropsychological Status in progressive supranuclear palsy

Objective: Progressive supranuclear palsy (PSP) is associated with a variety of cognitive deficits, but few studies have reported on its cognitive trajectory across time, especially on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).Methods: Two hundred twenty participants diagnosed with Richardson's syndrome of PSP (PSP-RS) were evaluated with the RBANS at baseline, six months, and one year with alternate forms.Results: When using dependent t-tests, significant declines were observed on all Indexes of the RBANS from baseline to six months (ps < 0.01). Between six months and one year, significant declines were observed on three Indexes of the RBANS (ps < 0.05). Using existing regression-based change formulae from cognitively intact older adults, these participants with PSP showed significant decline on all RBANS Indexes (ps < 0.01) across one year. Finally, new regression-based change formulae were developed on this sample of individuals with PSP-RS to more precisely evaluate cognitive change in this condition.Conclusion: In this large, longitudinal cohort of participants with PSP-RS, many (but not all) showed notable cognitive decline across six months and one year on the RBANS. The different methods of examining change across time yielded different results, with regression-based methods appearing to more accurately capture decline in this sample. These findings are expected to allow clinicians to more accurately evaluate cognitive trajectories in patients with PSP, as well as make better estimates of prognosis and offer more appropriate treatment recommendations. Such findings are also expected to inform clinical trials as to the changes in cognitive outcomes with this neurological condition.

Association between Lower Extremity Skeletal Muscle Mass and Impaired Cognitive Function in Type 2 Diabetes

Lower extremity skeletal muscle mass (LESM) in Type 2 Diabetes (T2D) has been linked to adverse clinical events, but it is not known whether it is associated with cognitive difficulties. We conducted a cross-sectional study on 1,235 people (mean age 61.4 ± 8.0 years) with T2D under primary and secondary care in Singapore. Bioelectrical impedance analyses (BIA) measures of upper extremity skeletal muscle mass (UESM), LESM and appendicular skeletal muscle index (SMI) were related to the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) measures of cognition, in multiple linear regression. In multivariable models, tertile 1 LESM (b = −2.62 (−3.92 to −1.32)) and tertile 2 LESM (b = −1.73 (−2.73 to −0.73)), referenced to tertile 3) were significantly associated with decreased RBANS total score. Significant associations of LESM with cognitive domain performances were observed for tertile 1 (b = −3.75 (−5.98 to −1.52)) and tertile 2 (b = −1.98 (−3.69 to −0.27)) with immediate memory, and for tertile 1 (b = −3.05 (−4.86 to −1.24)) and tertile 2 (b = −1.87 (−3.25 to −0.48)) with delayed memory, and for tertile 1 (b = −2.99 (−5.30 to −0.68)) with visuospatial/constructional ability. Tertile 1 SMI (b = −1.94 (−3.79 to −0.08) and tertile 2 SMI (b = −1.75 (−3.14 to −0.37)) were also associated with delayed memory. There were no associations between UESM with cognitive performance. Lower LESM may be a useful marker of possible co-occuring cognitive dysfunction.

Amnestic mild cognitive impairment in Parkinson's disease: White matter structural changes and mechanisms

Mild cognitive impairment (MCI) is a heterogeneous cognitive disorder that is often comorbid with Parkinson's diseases (PD). The amnestic subtype of PD-MCI (PD-aMCI) has a higher risk to develop dementia. However, there is a lack of studies on the white matter (WM) structural changes of PD-aMCI. We characterized the WM structural changes of PD-aMCI (n = 17) with cognitively normal PD (PD-CN, n = 19) and normal controls (n = 20), using voxel-based and tract-based spatial statistics (TBSS) analyses on fractional anisotropy (FA) axial diffusivity (AD), and radial diffusivity (RD). By excluding and then including the motor performance as a covariate in the comparison analysis between PD-aMCI and PD-CN, we attempted to discern the influences of two neuropathological mechanisms on the WM structural changes of PD-aMCI. The correlation analyses between memory and voxel-based WM measures in all PD patients were also performed (n = 36). The results showed that PD-aMCI had smaller FA values than PD-CN in the diffuse WM areas, and PD-CN had higher AD and RD values than normal controls in the right caudate. Most FA difference between PD-aMCI and PD-CN could be weakened by the motor adjustment. The FA differences between PD-aMCI and PD-CN were largely spatially overlapped with the memory-correlated FA values. Our findings demonstrated that the WM structural differences between PD-aMCI and PD-CN were mainly memory-related, and the influence of motor adjustment might indicate a common mechanism underlying both motor and memory impairment in PD-aMCI, possibly reflecting a predominant influence of dopaminergic neuropathology.

Cognitive deficits in progressive supranuclear palsy on the Repeatable Battery for the Assessment of Neuropsychological Status

Progressive supranuclear palsy (PSP) is associated with a variety of cognitive deficits, as well as motor and psychiatric disturbances. As clinical trials for PSP evolve, briefer screening instruments will be needed to determine cognitive effects of interventions. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) may fill this gap. Three hundred four participants diagnosed with Richardson's syndrome of PSP were evaluated with the RBANS, as well as other scales typically used in PSP. RBANS performances for these participants fell significantly below expectations for the Total Scale score and all five Indexes. Cognitive scores on the RBANS were also significantly related to other markers of PSP (e.g., motor and functional abilities, depression, global cognition). Compared to other clinical conditions from the literature, patients with PSP show impairment on tests of visuospatial perception and construction and attention. Although additional research is needed, the current study supports the clinical applicability of the RBANS in patients with PSP, as well as its potential for future clinical trials.

The Clinical Utility of the TYM and RBANS in a One-Stop Memory Clinic in Singapore: A Pilot Study

BACKGROUND

We aimed to examine the discriminant validity of a brief self-administered cognitive screening test, the Test Your Memory (TYM) and a brief neuropsychological test, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), supplemented with executive and language tests (Color Trail Test [CTT] and modified Boston Naming Test [mBNT], respectively), in detecting cognitive impairment (CI) in a one-stop memory clinic in Singapore.

METHODS

Ninety patients ≥50 years old with a diagnosis of no cognitive impairment, mild cognitive impairment, and mild Alzheimer disease were recruited from memory clinic. They received the TYM, Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), RBANS, CTT, mBNT, and a gold-standard formal neuropsychological test battery.

RESULTS

The TYM had a significantly larger area under the curve (AUC) than MMSE (0.96 vs 0.88, P = .03) and was equivalent to MoCA in detecting CI (0.96 vs 0.95, P = .80). At the optimal cutoff points, the TYM (<38) was significantly more sensitive than the MMSE (<24) and MoCA (<20; P < .001). The RBANS had an AUC equivalent to the RBANS supplemented with CTT and mBNT (0.92 vs 0.86, P = .22) in detecting CI. The RBANS supplemented with CTT and mBNT was more sensitive than RBANS alone in detecting CI (sensitivity: 0.98 vs 0.93, P = .016) among patients screened negative using TYM.

CONCLUSION

The self-administered TYM is superior to MMSE and equivalent to MoCA in detecting CI and could be implemented routinely. The RBANS supplemented with CTT and mBNT is more sensitive in detecting CI than RBANS alone therefore could be used for diagnostic purposes.

Super-cognition in aging: Cognitive profiles and associated lifestyle factors

Previous research on older adults with superior cognitive abilities (super-cognition) has typically examined cognition using a single domain approach, which may not adequately capture the multidimensional nature of successful cognitive aging. Furthermore, the lifestyle factors associated with super-cognition have not been studied adequately. The current study examined the cognitive profiles and lifestyle factors associated with super-cognition. Community-dwelling older adults (N = 693) were administered neuropsychological tests and self-reported measures of lifestyle factors at midlife (retrospectively recalled). Then, using an a priori set of criteria, we classified them as super-cognition or normal. A latent class analysis was conducted to examine the different cognitive profiles of super-cognition, and both groups were compared on their lifestyle-related outcomes. A total of 64 and 263 participants met the criteria for super-cognition and normal participants respectively. A three-class solution best described super-cognition among our participants. Approximately half of them had superior immediate memory; two other smaller groups of participants with super-cognition had superior attention, language, and visuospatial abilities. Participants with super-cognition reported less participation in social activities and, frequently, working more than 9 hours/day and feeling stressed, at midlife. Super-cognition among the elderly is associated with having a busier, more socially-isolated and stressful midlife.

Patterns of cognitive function in middle-aged and elderly Chinese adults-findings from the EMCOA study

Background

The principal aim of this study was to demonstrate the gender-specific cognitive patterns among middle-aged and elderly Chinese adults, investigate the risk factors on global and domain-specific cognitive performance in men and women, respectively, and report demographically adjusted norms for cognitive tests.

Methods

The Effects and Mechanism of Cholesterol and Oxysterol on Alzheimer’s disease (EMCOA) study enrolled 4573 participants aged 50–70 years in three Chinese cities. All participants underwent an extensive neuropsychological test battery. Composite scores for specific domains were derived from principal component analysis (PCA). Multivariate linear regression models were used to determine gender-specific risk factors and demographically adjusted normative data.

Results

Three cognitive domains of verbal memory, attention/processing speed/executive function, and cognitive flexibility were extracted. A female advantage in verbal memory was observed regardless of age, whereas men tended to outperform women in global cognition and attention/processing speed/executive function. The effects of education on women were more substantial than men for general cognition and attention/processing speed/executive function. For all the cognitive tests, regression-based and demographically adjusted normative data were calculated.

Conclusions

There is a need for gender-specific intervention strategies for operationalizing cognitive impairment.

Trial registration

EMCOA, ChiCTR-OOC-17011882. Retrospectively registered on 5 July 2017.

Electronic supplementary material

The online version of this article (10.1186/s13195-018-0421-8) contains supplementary material, which is available to authorized users.

Psychometric Properties of Alzheimer’s Disease Assessment Scale-Cognitive Subscale for Mild Cognitive Impairment and Mild Alzheimer’s Disease Patients in an Asian Context

Introduction: The purpose of the current study is to assess the psychometric properties of Alzheimer’s Disease Assessment Scale-Cognitive subscale (ADAS-Cog) on patients with mild cognitive impairment (MCI) and mild Alzheimer’s disease (AD) in a multicultural Asian context. Materials and Methods: Sixty-four mild AD patients (mean age ± SD; 72.24 ± 7.88 years), 80 MCI patients (66.44 ± 7.45 years) and 125 healthy controls (HCs) (61.81 ±6.96 years) participated in the study. Participants underwent a clinical interview and serial neuropsychological testing. ADAS-Cog total and subtest scores were compared across the 3 groups. Receiver operating characteristics (ROC) analysis were performed and sensitivity, specificity, positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. Results: Patients with MCI attained significantly worse neuropsychological test scores than healthy controls but significantly better results than patients with mild AD on ADAS-Cog total score, subtest items, and the delayed recall item (P <0.001). The best cutoff score to differentiate between MCI and HC was ≥4 (sensitivity = 0.73, specificity = 0.69, PPV = 0.90, NPV = 0.40), while the best cutoff score to distinguish between MCI and mild AD was ≥12 (sensitivity = 0.86, specificity = 0.89, PPV = 0.99, NPV = 0.32). Evidence of internal consistency of the ADAS-Cog (Cronbach α = 0.85) as well as convergent validity with the Mini-Mental State Examination (MMSE) (ρ = -0.75) and Montreal Cognitive Assessment (MoCA) (ρ = -0.81) (both P <0.001) was also found. Conclusion: The ADAS-Cog which is widely used in clinical trials is applicable to the Asian cohort. It is useful in the detection of MCI and mild AD as well as in distinguishing these 2 conditions. Key words: Dementia, Neuropsychology, Psychometric validation

The Diagnostic Utility of the NINDS-CSN Neuropsychological Battery in Memory Clinics

Aims

To examine the diagnostic utility of the National Institute of Neurological Disorders and Stroke and the Canadian Stroke Network (NINDS-CSN) neuropsychological battery in memory clinics comparing controls with patients with no cognitive impairment (NCI), patients with cognitive impairment-no dementia (CIND) at varying severity levels (mild/moderate), and patients with dementia.

Methods

A total of 405 participants with NCI, CIND or dementia were assessed with the NINDS-CSN battery. The discriminatory properties of all three protocols (5, 30 and 60 min) before and after education stratification (none/primary vs. secondary/above) were examined by receiver operating characteristic curves.

Results

Overall, the shorter protocols are equivalent to the longer protocol in diagnosing dementia, regardless of education. To discriminate between nondementia groups, before education stratification, the 5-min protocol showed varied discriminatory properties between different diagnostic/severity groups. After stratification, the 5-min protocol was broadly equivalent to the longer protocols in lower-education groups [area under the curve (AUC) range: 0.77-0.87] but was less accurate in the higher-education groups (AUC range: 0.68-0.78). The 30- and 60-min protocol constantly showed moderate-to-excellent differentiating capacities regardless of education (AUC range: 0.80-0.90).

Conclusion

The NINDS-CSN neuropsychological battery can be applied in memory clinics and effectively discriminate between cognitively intact individuals and those with cognitive impairments of varying severity. Furthermore, level of education should be taken into consideration when choosing protocols with different lengths for cognitive assessment.

Degree, but not direction of grip strength asymmetries, is related to depression and anxiety in an elderly population

Despite the abundance of studies on asymmetries in manual laterality, a marker for atypical brain lateralization in depression and anxiety, findings in this area are mixed. Traditionally, research have looked at individual differences in depression and anxiety as a function of the direction of asymmetry. However, recent research has emphasized on studying the degree of asymmetry in addition to its direction. To these ends, the present study aims to unravel the associations between the degree and direction of manual lateralization, and depression/anxiety. Cognitively healthy elderlies (N = 326, 91 males, M_age = 68) were administered grip strength assessments on both hands and self-report measures of depression and anxiety. Partial correlation analyses controlling for age, education and sex revealed significant positive associations between degree of lateralization and anxiety in the overall sample and among right-dominant participants, as well as a significant positive relationship between degree of lateralization and depression among right-dominant participants. None of the correlations involving the direction of lateralization yielded significance, neither was there significant differences between left- and right-dominant participants on depression and anxiety scores. These findings suggest that the degree of manual lateralization, but not direction, is related to depression and anxiety at least among right-dominant individuals.