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.

The Minimum Clinically Important Difference in the Repeatable Battery for the Assessment of Neuropsychological Status.

OBJECTIVE: There is no established minimum clinically important difference (MCID) for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) index and total scale scores. This study aimed to estimate the MCID for the RBANS index scores and total scale score. METHOD: Participants included 1,856 ethnic Chinese, older adults. Distribution- and anchor-based methods were used to estimate values for the MCID. Distribution-based estimates were calculated as the standard error of measurement (SEM) and .5 standard deviations (SD). For anchor-based estimates, we compared RBANS scores between the clinical dementia rating (CDR) scale no dementia and very mild dementia groups and between the clinical assessment of dementia (CAD) cognitively normal and mild cognitive impairment groups using regression models adjusting for demographic characteristics. RESULTS: Estimates from the CDR anchor were 7.79, 8.63, 10.74, 9.74, 5.61, and 3.77 for the total scale score, language, immediate memory, delayed memory, visuospatial/constructional, and the attention index, respectively. Estimates from the distribution-based methods were similar to the estimates based on the CDR, except for the language and attention indexes. Estimates from the CAD anchor were larger. CONCLUSIONS: We estimated the MCID for the total scale score, language, immediate memory, delayed memory, visuospatial/constructional, and attention indexes of the RBANS as 8, 9, 10, 10, 6, and 4 points, respectively. These estimates are best suited to discriminate between patient groups, for example, in a clinical trial setting. Further research is needed using longitudinal data to assess their applicability to assess within patient differences.

The Equivalence and Difference between the English and Chinese Language Versions of the Repeatable Battery for the Assessment of Neuropsychological Status.

OBJECTIVE: Chinese is the most commonly spoken language in the world. The availability of Chinese translations of assessment scales is useful for research in multi-ethnic and multinational studies. This study aimed to establish whether each of the Chinese translations (Mandarin, Hokkien, Teochew, and Cantonese) of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) achieved measurement equivalence to the English version. METHOD: Participants included 1856 ethnic Chinese, older adults. The RBANS was administered in the language/dialect according to the participants' preference by interviewers who were fluent in that language/dialect. Multiple regression analysis was used to adjust for demographic and clinical differences between participants who spoke different languages/dialects. Equivalence (practical equivalence) was declared if the 90% confidence interval for the adjusted mean difference fell entirely within the pre-specified equivalence margin, ±.2 (±.4) standard deviations. RESULTS: The delayed memory index was at least practically equivalent across languages. The Mandarin, Hokkien, and Teochew versions of the immediate memory, language, and total scale score were practically equivalent to the English version; the Cantonese version showed small differences from the English version. Equivalence was not established for the Hokkien and Teochew versions of the visuospatial/constructional index. The attention index was different across languages. CONCLUSIONS: Data from the English and Chinese versions for the total scale score, language, delayed, and immediate memory indexes may be pooled for analysis. However, analysis of the attention and visuospatial/constructional indexes from the English and Chinese versions should include a covariate that represents the version in the statistical adjustment.

Normative data for the repeatable battery for the assessment of neuropsychological status in elderly Chinese.

Asia will experience a surge in dementia prevalence within the next 20-40 years, but there is a dearth of well-normed neuropsychological tests that could assist with dementia diagnosis. Here, we report normative data for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in Elderly ethnic Chinese Singaporeans aged 55-91 years of age. A total of 1,165 male and female community-dwelling, cognitively normal elderly Chinese persons in Singapore, with varying levels of education and range of languages, were tested with the RBANS version A. The effects of age, education, language and gender on RBANS performance were examined. Negative effects of increased age and positive effects of education on the RBANS subtests, Index and Total Scale scores were found suggesting differential associations between age-related cognitive decline and education that vary according to the specific cognitive ability measured. The findings indicate that unique cultural and educational profile of elderly Chinese should be considered when applying the RBANS in this population.

Improving screening for vascular cognitive impairment at three to six months after mild ischemic stroke and transient ischemic attack.

BACKGROUND: The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were compared with and without the addition of a brief processing speed test, the symbol digit modalities test (SDMT), for vascular cognitive impairment (VCI) screening at three to six months after stroke. METHODS: Patients with ischemic stroke and transient ischemic attack were assessed with MoCA and MMSE, as well as a formal neuropsychological battery three to six months after stroke. VCI was defined by impairment in any cognitive domain on neuropsychological testing. The area under the receiver operating characteristic curve (AUC) was used to compare test discriminatory ability. RESULTS: One hundred and eighty-nine patients out of 327 (58%) had VCI, of whom 180 (95%) had vascular mild cognitive impairment (VaMCI), and nine (5%) had dementia. The overall AUCs of the MoCA and MMSE scores and performance at their respective cut-off points were equivalent in detecting VCI (AUCs: 0.87 (95% CI 0.83-0.91) vs. 0.84 (95% CI 0.80-0.88), p = 0.13; cut-offs: MoCA (≤23) vs. MMSE (≤26), sensitivity: 0.78 vs. 0.71; specificity: 0.80 vs. 0.82; positive predictive value: 0.84 vs. 0.84; negative predictive value: 0.72 vs. 0.67; and correctly classified 78.6% vs. 75.5%; p = 0.42). The AUCs of MMSE and MoCA were improved significantly by the SDMT (AUCs: MMSE+SDMT 0.90 (95% CI 0.87-0.93), p <0.001; MoCA+SDMT 0.91 (95% CI 0.88-0.94), p < 0.02). CONCLUSIONS: The MoCA and MMSE are equivalent and moderately sensitive, and can be supplemented with the SDMT to improve their accuracy in VCI screening.

Cognitive screening improves the predictive value of stroke severity scores for functional outcome 3-6 months after mild stroke and transient ischaemic attack: an observational study.

OBJECTIVES: To investigate the prognostic value of the neurocognitive status measured by screening instruments, the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE), individually and in combination with the stroke severity scale, the National Institute of Health Stroke Scale (NIHSS), obtained at the subacute stroke phase or the baseline (≤2 weeks), for functional outcome 3-6 months later. DESIGN: Prospective observational study. SETTING: Tertiary stroke neurology service. PARTICIPANTS: 400 patients with a recent ischaemic stroke or transient ischaemic attack (TIA) received NIHSS, MoCA and MMSE at baseline and were followed up 3-6 months later. PRIMARY OUTCOME MEASURES: At 3-6 months following the index event, functional outcome was measured by the modified Rankin Scale (mRS) scores. RESULTS: Most patients (79.8%) had a mild ischaemic stroke and less disability (median NIHSS=2, median mRS=2 and median premorbid mRS=0), while a minority of patients had TIA (20.3%). Baseline NIHSS, MMSE and MoCA scores individually predicted mRS scores at 3-6 months, with NIHSS being the strongest predictor (NIHSS: R(2) change=0.043, p<0.001). Moreover, baseline MMSE scores had a small but statistically significant incremental predictive value to the baseline NIHSS for mRS scores at 3-6 months, while baseline MoCA scores did not (MMSE: R(2) changes=0.006, p=0.03; MoCA: R(2) changes=0.004, p=0.083). However, in patients with more severe stroke at baseline (defined as NIHSS>2), baseline MoCA and MMSE had a significant and moderately large incremental predictive value to the baseline NIHSS for mRS scores at 3-6 months (MMSE: R(2) changes=0.021, p=0.010; MoCA: R(2) changes=0.017, p=0.021). CONCLUSIONS: Cognitive screening at the subacute stroke phase can predict functional outcome independently and improve the predictive value of stroke severity scores for functional outcome 3-6 months later, particularly in patients with more severe stroke.

Association of silent lacunar infarct with brain atrophy and cognitive impairment.

OBJECTIVE: Silent lacunar infarct (SLI) is associated with cognitive decline and linked to an increased risk of stroke and dementia. We examined the association of SLI with MRI measures of cortical thickness, subcortical and lateral ventricular shapes and cognition in 285 ethnic Chinese elderly. METHODS: SLI, cortical thickness, shapes of subcortical and ventricular structures were quantified using MRI. The cognitive performance was assessed using comprehensive neuropsychological tests. Linear regression was used to examine associations among SLI, brain measures and cognition. RESULTS: SLI was associated with atrophy in multiple subcortical structures, ventricular enlargement and widespread cortical thinning. Both SLI and atrophy were independently related to poorer performance in attention, memory and language domains. Only SLI was associated with visuomotor speed and executive function, while atrophy mediated the association between SLI and visuoconstruction. CONCLUSIONS: Our findings support a vascular contribution to neurodegeneration and cognitive impairment.

Patterns of neuropsychological impairment in Alzheimer's disease and mixed dementia.

BACKGROUND: Mixed dementia (MD), i.e., the coexistence of Alzheimer's disease (AD) and cerebrovascular disease (CVD), is a common dementia subtype. Few studies have attempted to establish the cognitive profiles of mild-moderate MD and compare it to the profiles of AD using a comprehensive neuropsychological test battery. We aimed to establish the neuropsychological profile of mild-moderate MD in relation to mild-moderate AD. METHODS: Patients with consensus diagnoses of MD and AD of mild-moderate severity (Clinical Dementia Rating score of 1-2) were recruited from a memory clinic. Cognitive performance was measured by a formal neuropsychological battery covering domains of attention, language, verbal and visual memory, visuoconstruction, visuomotor speed and executive function. Cognitive domain scores are z-scores calculated using the mean and SDs of the AD group. ANCOVAs with age and education as covariates were employed to examine differences in mean score difference of cognitive domains and subtests between patients with MD and AD. RESULTS: 151 patients were recruited with the majority of AD (n=96, 63.6%) and a minority of MD (n=55, 36.4%). There were no significant differences in the demographic characteristics of patients with MD and AD. However, patients with MD were significantly more impaired than AD patients in global cognitive composite, attention and visuoconstruction (global cognitive composite: -0.32±0.98 vs 0±1, p=0.011; attention: -0.32±0.90 vs 0±1, p=0.013; visuoconstruction: -0.27±0.99 vs 0±1, p=0.024, respectively). CONCLUSION: The neuropsychological profile of patients with MD of mild-moderate severity is characterized by a poorer global performance, as well as attention and visuoconstruction than those with AD of mild-moderate severity.

Brief assessment of cognition in schizophrenia: normative data in an English-speaking ethnic Chinese sample.

There is a dearth of non-Western normative data for neuropsychological batteries designed to measure cognitive deficits in schizophrenia. Here, we provide normative data for English-speaking ethnic Chinese on the widely used Brief Assessment of Cognition in Schizophrenia acquired from 595 healthy community participants between ages 14 and 55. Means and standard deviations of subtests and composite scores were stratified by age group and sex. We also explored linear regression approaches to generate continuous norms adjusted for age, sex, and education. Notable differences in subtest performances were found against a Western comparison sample. Normative data established in the current sample are essential for clinical and research purposes as it serves as a reference source of cognition for ethnic Chinese.

Formulation of the age-education index: measuring age and education effects in neuropsychological performance.

The complex interplay of education, age, and cognitive performance on various neuropsychological tests is examined in the current study. New education indices were formulated and further investigated to reveal how age and education variances work together to account for performance on neuropsychological tests. Participants were 830 English-speaking ethnic Chinese. Neuropsychological measures such as Verbal Memory, Digit Sequencing, Token Motor Task, Semantic Fluency, Symbol Coding, Tower of London, Judgment of Line Orientation, and Matrix Reasoning of the Wechsler Adult Intelligence Scale were administered. Education was measured by total years of education and adjusted years of education, as well as ratios of both measures with age. Age and education were associated with neuropsychological performance. Adjusted years of education was associated with fluency and higher cognitive processes, while the ratio between adjusted years of education and age was associated with tasks implicating working memory. Changes in education modalities implicated tasks requiring language abilities. Education and age represent key neurodevelopmental milestones. In light of our findings, special consideration should to be given when neuropsychological assessments are carried out in cross-cultural contexts and in societies where educational systems and pedagogy tend to be complex.

The Montreal Cognitive Assessment is superior to the Mini-Mental State Examination in detecting patients at higher risk of dementia.

BACKGROUND: To examine the discriminant validity of the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) in detecting patients with cognitive impairment at higher risk for dementia at a memory clinic setting. METHODS: Memory clinic patients were administered the MoCA, MMSE, and a comprehensive formal neuropsychological battery. Mild cognitive impairment (MCI) subtypes were dichotomized into two groups: single domain-MCI (sd-MCI) and multiple domain-MCI (md-MCI). Area under the receiver operating characteristic curve (ROC) analysis was used to compare the discriminatory ability of the MoCA and the MMSE. RESULTS: Two hundred thirty patients were recruited, of which 136 (59.1%) were diagnosed with dementia, 61 (26.5%) with MCI, and 33 (14.3%) with no cognitive impairment (NCI). The majority of MCI patients had md-MCI (n = 36, 59%). The MoCA had significantly larger AUCs than the MMSE in discriminating md-MCI from the lower risk group for incident dementia (NCI and sd-MCI) [MoCA 0.92 (95% CI, 0.86-0.98) vs. MMSE 0.84 (95% CI, 0.75-0.92), p = 0.02). At their optimal cut-off points, the MoCA (19/20) remained superior to the MMSE (23/24) in detecting md-MCI [sensitivity: 0.83 vs. 0.72; specificity: 0.86 vs. 0.83; PPV: 0.79 vs. 0.72; NPV: 0.89 vs. 0.83; correctly classified: 85.1% vs. 78.7%]. CONCLUSION: The MoCA is superior to the MMSE in the detection of patients with cognitive impairment at higher risk for incident dementia at a memory clinic setting.

Brief screening tests during acute admission in patients with mild stroke are predictive of vascular cognitive impairment 3-6 months after stroke.

OBJECTIVES: To determine the prognostic value of brief cognitive screening tests administered in the subacute stroke phase (initial 2 weeks) for the detection of significant cognitive impairment 3-6 months after stroke, the authors compared the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). METHODS: Patients with ischaemic stroke and transient ischaemic attack were assessed with both MoCA and MMSE within 14 days after index stroke, followed by a formal neuropsychological evaluation of seven cognitive domains 3-6 months later. Cognitive outcomes were dichotomised as either no-mild (impairment in ≤2 cognitive domains) or moderate-severe (impairment in ≥ 3 cognitive domains) vascular cognitive impairment. Area under the receiver operating characteristic (ROC) curve analysis was used to compare discriminatory ability. RESULTS: 300 patients were recruited, of whom 239 received formal neuropsychological assessment 3-6 months after the stroke. 60 (25%) patients had moderate-severe VCI. The overall discriminant validity for detection of moderate-severe cognitive impairment was similar for MoCA (ROC 0.85 (95% CI 0.79 to 0.90) and MMSE (ROC 0.83 (95% CI 0.77 to 0.89)), p=0.96). Both MoCA (21/22) and MMSE (25/26) had similar discriminant indices at their optimal cutoff points; sensitivity 0.88 versus 0.88; specificity 0.64 versus 0.67; 70% versus 72% correctly classified. Moreover, both tests had similar discriminant indices in detecting impaired cognitive domains. CONCLUSIONS: Brief screening tests during acute admission in patients with mild stroke are predictive of significant vascular cognitive impairment 3-6 months after stroke.

Inhibition of return: a "depth-blind" mechanism?

When attention is oriented to a peripheral visual event, observers respond faster to stimuli presented at a cued location than at an uncued location. Following initial reaction time facilitation responses are slower to stimuli subsequently displayed at the cued location, an effect known as inhibition of return (IOR). Both facilitatory and inhibitory effects have been extensively investigated in two-dimensional space. Facilitation has also been documented in three-dimensional space, however the presence of IOR in 3D space is unclear, possibly because IOR has not been evaluated in an empty 3D space. Determining if IOR is sensitive to the depth plane of stimuli or if only their bi-dimensional location is inhibited may clarify the nature of the IOR. To address this issue, we used an attentional cueing paradigm in three-dimensional (3D) space. Results were obtained from fourteen participants showed IOR components in 3D space when binocular disparity was used to induce depth. We conclude that attentional orienting in depth operates as efficiently as in the bi-dimensional space.

Altered depth perception is associated with presence of schizotypal personality traits.

INTRODUCTION: Impaired depth perception, a fundamental aspect of early visual processing, has been shown in patients with schizophrenia suggesting a disturbance to magnocellular and possibly parvocellular pathways. Despite some evidence showing visual-perceptive deficits in people with schizotypal personality traits (SPT), depth perception has not been evaluated in these subjects. METHODS: 12 clinically healthy schizotypy and 17 control participants were examined using a novel stereoscopic depth perception task. A mixed ANOVA design considered the Group (SPT/control) as independent factor, and trial Block (BD/BD+/BD-) and target Condition (SDSS/SDDS/DDSS/DDDS) were considered as repeated measures. RESULTS: Schizotypal participants were not significantly different to controls on simple judgements of depth but demonstrated a subtle impairment in perceiving binocular depth when performing high difficulty judgements. CONCLUSIONS: The presence of subtle depth perception problems in schizotypal subjects, similar but less marked than those of schizophrenia patients, may suggest a less pervasive disturbance of early information processing. If so, such deficits could be considered as innate neurological changes that may occur in people vulnerable for schizophrenia, thus with the potential to be a novel intermediate phenotype.

Cross-cultural application of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS): performances of elderly Chinese Singaporeans.

There is a paucity of normative studies outside of North America and on elderly populations with very low education level. In the present study we examined the performance of poorly educated elderly on the Repeatable Battery Assessment of Neuropsychological Status (RBANS) with 352 cognitively normal elderly Chinese persons living in the community in Singapore who were enrolled in the Singapore Longitudinal Ageing Study (SLAS). Those with no formal education performed significantly less well than those with some years of formal education across four of five RBANS indices as well as the Total Scale score. Age- and education-adjusted normative data for the RBANS were established for the sample. The means and standard deviations of each of 12 subtests raw scores, five Index scores and the Total Scale score were calculated and stratified by age and education. Data from the present study should considerably advance the clinical utility of the RBANS in Chinese geriatric evaluations in Singapore, and can serve as a reference source for poorly educated elderly Chinese from around the region and beyond.

Increased ratio of 2nd to 4th digit (2D:4D) in schizophrenia.

Sex differences in the onset, epidemiology, clinical presentation and neuropathology of schizophrenia suggest that sexual dimorphism in brain development may be relevant to pathogenesis. Sex hormones, in particular testosterone, are considered to be crucial in brain development, but few investigations have examined the potential role of prenatal testosterone in schizophrenia. In this study, we examined a retrospective marker of prenatal testosterone release - 2D:4D finger length ratio (2D:4D), the relative length of 2nd to 4th digit, in 64 Asian patients with schizophrenia and 64 sex-matched controls. No significant difference in mean finger lengths was present, however 2D:4D ratio was significantly different between patients and controls. The effect was primarily seen in males consistent with a 'less masculinised' pattern and hypotheses suggesting that schizophrenia may be associated with an abnormality in prenatal circulating testosterone.

Chronic impairment of prospective memory after mild traumatic brain injury.

Prospective memory (PM), the ability to recall future intentions, is crucial for independent living. Impairment of PM is a common complaint following head injury and is a significant impediment to good recovery, yet no studies have explored PM in mild traumatic brain injury (mTBI). In this study, prospective memory was examined in 31 mTBI patients and matched controls within a month of injury and 3 months after. mTBI patients performed more poorly than controls on the MIST task (Raskin, 2004) within the first month following injury, indicating that PM impairment is part of the acute cognitive sequelae of mTBI. These problems persisted beyond 3 months post-injury, suggesting that PM may be a sensitive indicator of cerebral compromise in mild brain injuries.

Duration of illness, regional brain morphology and neurocognitive correlates in schizophrenia.

INTRODUCTION: Previous studies examining brain effects of duration of illness in schizophrenia have focused on either cortical or subcortical structures. Hence this study sought to elucidate the regional grey matter changes (both cortical and subcortical) and neurocognitive correlates with increased duration of illness in a large sample of patients with schizophrenia using voxel-based morphometry. MATERIALS AND METHODS: Ninety patients (72 males and 18 females) with DSM-IV diagnosis of schizophrenia were recruited and assessed using magnetic resonance imaging and a battery of neuropsychological tests. RESULTS: A longer duration of illness was associated with smaller grey matter volumes in the left superior frontal gyrus, bilateral putamen, right superior temporal gyrus, right superior occipital gyrus as well as the right thalamus. No region showed increased grey matter volume above threshold with longer duration of illness. Longer duration of illness was correlated with poorer attention. CONCLUSIONS: The grey matter reductions in different brain regions highlighted that a distributed network of cortical and subcortical regions was associated with duration of illness. This is consistent with neural models that implicate involvement of thalamo-cortical circuitry as the disruption in these neural pathways can result in specific deficits such as poorer attention. The results have implications for the understanding of brain changes in schizophrenia, and with further studies, may guide better tailored and targeted clinical management in terms of reducing the impact of duration of illness on neural substrates in schizophrenia in the future.