Psychometric differentiation of mild senile dementia of the Alzheimer type

Diffusion tensor imaging analysis along the perivascular space in the UK biobank

BACKGROUND

The recently discovered glymphatic system may support the removal of neurotoxic proteins, mainly during sleep, that are associated with neurodegenerative diseases such as Alzheimer's and Parkinson's Disease. Diffusion tensor image analysis along the perivascular space (DTI-ALPS) has been suggested as a method to index the health of glymphatic system (with higher values indicating a more intact glymphatic system). Indeed, in small-scale studies the DTI-ALPS index has been shown to correlate with age, cognitive health, and sleep, and is higher in females than males.

OBJECTIVE

To determine whether these relationships are stable we replicated previous findings associating the DTI-ALPS index with demographic, sleep-related, and cognitive markers in a large sample of participants from the UK Biobank.

METHODS

We calculated the DTI-ALPS index in UK Biobank participants (n = 17723). Using Bayesian and Frequentist analysis approaches, we replicate previously reported relationships between the DTI-ALPS index.

RESULTS

We found the predicted associations between the DTI-ALPS index and age, longest uninterrupted sleep window (LUSWT) on a typical night, cognitive performance, and sex. However, these effects were substantially smaller than those found in previous studies. Parameter estimates from this study may be used as priors in subsequent studies using a Bayesian approach. These results suggest that the DTI-ALPS index is consistently, and therefore predictably, associated with demographics, LUWST, and cognition.

CONCLUSION

We propose that the metric, calculated for the first time in a large-scale, population-based cohort, is a stable measure, but one for which stronger links to glymphatic system function are needed before it can be used to understand the relationships between glymphatic system function and health outcomes reported in the UK Biobank.

Magnetic Resonance T1w/T2w Ratio in the Putamen and Cerebellum as a Marker of Cognitive Impairment in MSA: a Longitudinal Study

The exact pathophysiology of cognitive impairment in multiple system atrophy (MSA) is unclear. In our longitudinal study, we aimed to analyze (I) the relationships between cognitive functions and some subcortical structures, such as putamen and cerebellum assessed by voxel-based morphometry (VBM) and T1-weighted/T2-weighted (T1w/T2w) ratio, and (II) the neuroimaging predictors of the progression of cognitive deficits. Twenty-six patients with MSA underwent a comprehensive neuropsychological battery, motor examination, and brain MRI at baseline (T0) and 1-year follow-up (T1). Patients were then divided according to cognitive status into MSA with normal cognition (MSA-NC) and MSA with mild cognitive impairment (MCI). At T1, we divided the sample according to worsening/non worsening of cognitive status compared to baseline evaluation. Logistic regression analysis showed that age (β =  - 9.45, p = .02) and T1w/T2w value in the left putamen (β = 230.64, p = .01) were significant predictors of global cognitive status at T0, explaining 65% of the variance. Logistic regression analysis showed that ∆-values of WM density in the cerebellum/brainstem (β = 2188.70, p = .02) significantly predicted cognitive worsening at T1, explaining 64% of the variance. Our results suggest a role for the putamen and cerebellum in the cognitive changes of MSA, probably due to their connections with the cortex. The putaminal T1w/T2w ratio may deserve further studies as a marker of cognitive impairment in MSA.

Remember This: Age Moderation of Genetic and Environmental Contributions to Verbal Episodic Memory from Midlife through Late Adulthood

It is well documented that memory is heritable and that older adults tend to have poorer memory performance than younger adults. However, whether the magnitudes of genetic and environmental contributions to late-life verbal episodic memory ability differ from those at earlier ages remains unresolved. Twins from 12 studies participating in the Interplay of Genes and Environment in Multiple Studies (IGEMS) consortium constituted the analytic sample. Verbal episodic memory was assessed with immediate word list recall (N = 35,204 individuals; 21,792 twin pairs) and prose recall (N = 3,805 individuals; 2,028 twin pairs), with scores harmonized across studies. Average test performance was lower in successively older age groups for both measures. Twin models found significant age moderation for both measures, with total inter-individual variance increasing significantly with age, although it was not possible definitively to attribute the increase specifically to either genetic or environmental sources. Pooled results across all 12 studies were compared to results where we successively dropped each study (leave-one-out) to assure results were not due to an outlier. We conclude the models indicated an overall increase in variance for verbal episodic memory that was driven by a combination of increases in the genetic and nonshared environmental parameters that were not independently statistically significant. In contrast to reported results for other cognitive domains, differences in environmental exposures are comparatively important for verbal episodic memory, especially word list learning.

Antemortem Visit-To-Visit Blood Pressure Variability Predicts Cerebrovascular Lesion Burden in Autopsy-Confirmed Alzheimer's Disease

BACKGROUND

Blood pressure variability is linked to Alzheimer's disease (AD) risk and MRI-based markers of cerebrovascular disease. Less is known about the role of blood pressure variability in postmortem evaluation of cerebrovascular disease and AD.

OBJECTIVE

To determine whether antemortem blood pressure variability predicts cerebrovascular and AD pathology and follow-up cognitive change in autopsy-confirmed AD.

METHODS

National Alzheimer's Coordinating Center participants (n = 513) underwent 3-4 approximately annual blood pressure measurements and were confirmed to have AD at postmortem evaluation. A subset (n = 493) underwent neuropsychological evaluation at follow-up. Regression models examined relationships between blood pressure variability and cerebrovascular and AD pathological features and follow-up cognitive change.

RESULTS

Elevated blood pressure variability predicted increased postmortem cerebrovascular lesion burden (ß = 0.26 [0.10, 0.42]; p = 0.001; R2 = 0.12). Increased blood pressure variability predicted specific cerebrovascular lesion severity, including atherosclerosis in the Circle of Willis (OR = 1.22 [1.03, 1.44]; p = 0.02) and cerebral arteriolosclerosis (OR = 1.32 [1.04, 1.69]; p = 0.03). No significant relationships were observed between blood pressure variability and AD pathological findings, including Braak & Braak stage, neuritic plaques or diffuse plaques, or cerebral amyloid angiopathy, or follow-up cognitive decline.

CONCLUSION

Findings suggest that elevated blood pressure variability is related to postmortem cerebrovascular lesion burden in autopsy-confirmed AD, independent of average blood pressure and AD neuropathology. Blood pressure fluctuation may selectively promote atherosclerotic and arteriolosclerotic brain lesions with potential implications for cognitive impairment and dementia.

Age differences in resting state EEG and their relation to eye movements and cognitive performance

Prior research has focused on EEG differences across age or EEG differences across cognitive tasks/eye tracking. There are few studies linking age differences in EEG to age differences in behavioural performance which is necessary to establish how neuroactivity corresponds to successful and impaired ageing. Eighty-six healthy participants completed a battery of cognitive tests and eye-tracking measures. Resting state EEG (n = 75, 31 young, 44 older adults) was measured for delta, theta, alpha and beta power as well as for alpha peak frequency. Age deficits in cognition were aligned with the literature, showing working memory and inhibitory deficits along with an older adult advantage in vocabulary. Older adults showed poorer eye movement accuracy and response times, but we did not replicate literature showing a greater age deficit for antisaccades than for prosaccades. We replicated EEG literature showing lower alpha peak frequency in older adults but not literature showing lower alpha power. Older adults also showed higher beta power and less parietal alpha power asymmetry than young adults. Interaction effects showed that better prosaccade performance was related to lower beta power in young adults but not in older adults. Performance at the trail making test part B (measuring task switching and inhibition) was improved for older adults with higher resting state delta power but did not depend on delta power for young adults. It is argued that individuals with higher slow-wave resting EEG may be more resilient to age deficits in tasks that utilise cross-cortical processing.

Cognitive Assessment via Telephone: A Scoping Review of Instruments

OBJECTIVE

Telephone-based cognitive assessment (TBCA) has long been studied but less widely adopted in routine neuropsychological practice. Increased interest in remote neuropsychological assessment techniques in the face of the coronavirus 2019 (COVID-19) pandemic warrants an updated review of relevant remote assessment literature. While recent reviews of videoconference-based neuropsychological applications have been published, no updated compilation of empirical TBCA research has been completed. Therefore, this scoping review offers relevant empirical research to inform clinical decision-making specific to teleneuropsychology.

METHOD

Peer-reviewed studies addressing TBCA were included. Broad search terms were related to telephone, cognitive, or neuropsychological assessment and screening. After systematic searching of the PubMed and EBSCO databases, 139 relevant articles were retained.

RESULTS

In total, 17 unique cognitive screening measures, 20 cognitive batteries, and 6 single-task measures were identified as being developed or adapted specifically for telephone administration. Tables summarizing the identified cognitive assessments, information on diagnostic accuracy, and comparisons to face-to-face cognitive assessment are included in supplementary materials.

CONCLUSIONS

Overall, literature suggests that TBCA is a viable modality for identifying cognitive impairment in various populations. However, the mode of assessment selected clinically should reflect an understanding of the purpose, evidence, and limitations for various tests and populations. Most identified measures were developed for research application to support gross cognitive characterization and to help determine when more comprehensive testing was needed. While TBCA is not meant to replace gold-standard, face-to-face evaluation, if appropriately utilized, it can expand scope of practice, particularly when barriers to standard neuropsychological assessment occur.

New normative data from the Spanish-language version of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), form A

INTRODUCTION

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is frequently used in clinical practice to evaluate cognitive function. It is quick to administer (20-30minutes) and is not influenced by a learning effect. The RBANS includes 4 parallel versions and has a high discriminative ability. Our study provides normative data from the RBANS-E (Spanish-language version of RBANS form A) for a Spanish population aged 20 to 89 years.

METHODS

The study included 609 subjects aged 20 to 89 years. Participants were evaluated at baseline with a short interview, a cognitive screening test (Mini-Mental State Examination), and a functional scale (Rapid Disability Rating Scale). The RBANS-E was then administered to all 609 participants.

RESULTS

Our results show the influence of education on all subtest scores. Sex was observed to have no impact on any subtest.

CONCLUSION

Our study provides highly useful normative data for the cognitive evaluation of young and adult populations.

Alzheimer's Disease: Past, Present, and Future

Although dementia has been described in ancient texts over many centuries (e.g., "Be kind to your father, even if his mind fail him." - Old Testament: Sirach 3:12), our knowledge of its underlying causes is little more than a century old. Alzheimer published his now famous case study only 110 years ago, and our modern understanding of the disease that bears his name, and its neuropsychological consequences, really only began to accelerate in the 1980s. Since then we have witnessed an explosion of basic and translational research into the causes, characterizations, and possible treatments for Alzheimer's disease (AD) and other dementias. We review this lineage of work beginning with Alzheimer's own writings and drawings, then jump to the modern era beginning in the 1970s and early 1980s and provide a sampling of neuropsychological and other contextual work from each ensuing decade. During the 1980s our field began its foundational studies of profiling the neuropsychological deficits associated with AD and its differentiation from other dementias (e.g., cortical vs. subcortical dementias). The 1990s continued these efforts and began to identify the specific cognitive mechanisms affected by various neuropathologic substrates. The 2000s ushered in a focus on the study of prodromal stages of neurodegenerative disease before the full-blown dementia syndrome (i.e., mild cognitive impairment). The current decade has seen the rise of imaging and other biomarkers to characterize preclinical disease before the development of significant cognitive decline. Finally, we suggest future directions and predictions for dementia-related research and potential therapeutic interventions. (JINS, 2017, 23, 818-831).

Process dissociation analyses of memory changes in healthy aging, preclinical, and very mild Alzheimer disease: Evidence for isolated recollection deficits

OBJECTIVE

Recollection and familiarity are independent processes that contribute to memory performance. Recollection is dependent on attentional control, which has been shown to be disrupted in early stage Alzheimer's disease (AD), whereas familiarity is independent of attention. The present longitudinal study examines the sensitivity of recollection estimates based on Jacoby's (1991) process dissociation procedure to AD-related biomarkers in a large sample of well-characterized cognitively normal middle-aged and older adults (N = 519) and the extent to which recollection discriminates these individuals from individuals with very mild symptomatic AD (N = 64).

METHOD

Participants studied word pairs (e.g., knee bone), then completed a primed, explicit, cued fragment-completion memory task (e.g., knee b_n_). Primes were either congruent with the correct response (e.g., bone), incongruent (e.g., bend), or neutral (e.g., &&&). This design allowed for the estimation of independent contributions of recollection and familiarity processes, using the process dissociation procedure.

RESULTS

Recollection, but not familiarity, was impaired in healthy aging and in very mild AD. Recollection discriminated cognitively normal individuals from the earliest detectable stage of symptomatic AD above and beyond standard psychometric tests. In cognitively normal individuals, baseline CSF measures indicative of AD pathology were related to lower initial recollection and less practice-related improvement in recollection over time. Finally, presence of amyloid plaques, as imaged by PIB-PET, was also related to less improvement in recollection over time.

CONCLUSIONS

These findings suggest that attention-demanding memory processes, such as recollection, may be particularly sensitive to both symptomatic and preclinical AD pathology. (PsycINFO Database Record

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

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

A simple score system for clock drawing in patients with Alzheimer's disease

Objective: To develop a simple clock drawing score system for patients with Alzheimer's disease, that correlates with the MMSE (Folstein Mini Mental Status Examination).1

Design: A retrospective analysis of 88 patients with the diagnosis of Alzheimer's disease

Setting: Outpatient Memory Disorder Institute of a large community teaching hospital.

Measurements: MMSE score and two different clock drawing ratings. The MMSE and the clock drawing scoring were performed by different raters. We present a “simple clock scoring system” and compared it with a previously published scoring system by Sunderland et al,2 referred to as the standard score system.

Results: There is a strong correlation between the “new score system” and the standard scoring (Pearsons Correlation Coefficient r = 0.91, p < 0.001). However, when both systems were evaluated in a multivariate linear regression analysis, the “ simple score system “ was a significant predictor of Folstein MMSE (P < 0.01), while the standard scoring system was not.

Conclusion: The “simple score system” is an easy to use, accurate predictor of the MMSE score, in patients with the diagnosis of Alzheimer's disease.

Performance Components in Senile Dementia of the Alzheimer Type: Motor Planning, Language, and Memory

This study was designed to determine if language, motor planning and memory could be identified as discrete components of performance. One hundred and thirty-three control subjects and 141 subjects diagnosed as having senile dementia of the Alzheimer type (SDAT) were studied The results suggest that the patterns of deficits in language, memory, and praxis are highly individualized Previous work has demonstrated the presence of apraxia in moderately and severely demented persons, and this study suggests that apraxia contributes significantly to dysfunction in some persons with SDAT. The results of this investigation support the need for multidimensional assessment and individualized care planning for persons with SDAT.

A Novel Plasma Based Biomarker of Alzheimer's Disease

Specific biomarkers in a readily accessible biological fluid, such as blood, could aid in the identification, characterization, validation, and routine monitoring of Alzheimer's disease (AD) progression. In the current study, levels of the previously described novel cerebrospinal fluid aberrant protein complex composed of prostaglandin-D-synthase (PDS) and transthyretin (TTR) were quantified in plasma by a custom two-probe sandwich ELISA and compared to amyloid-β (Aβ)(1-42) as a standard plasma biomarker of AD. Plasma was analyzed from 140 probable AD subjects, 135 subjects with mild cognitive impairment (MCI), 74 normal control subjects (NC) prior to MCI transition, 23 diseased control (DC) subjects with either frontotemporal dementia or dementia with Lewy bodies, and 182 normal control (NC) subjects who did not progress to MCI or dementia. Levels of Aβ(1-42) were significantly elevated in NC subjects prior to MCI conversion but significantly reduced in probable AD subjects compared to NC subjects. Similarly, levels of the PDS-TTR complex were significantly reduced in both MCI and probable AD subjects compared to NC subjects. Furthermore, levels of Aβ(1-42) and the PDS-TTR complex were not significantly different in DC subjects compared to NC subjects. MMSE scores were weakly but significantly correlated with plasma levels of the PDS-TTR complex and Aβ(1-42). Trail B scores were weakly but significantly correlated with plasma levels of Aβ(1-42). Comparison of receiver operating curves shows the PDS-TTR complex is comparable to Aβ(1-42) in both MCI and probable AD subjects.

Distinguishing between impairments of working memory and inhibitory control in cases of early dementia

Dementia (most notably, Alzheimer's Disease) is often associated with impairments of both working memory and inhibitory control. However, it is unclear whether these are functionally distinct impairments. We addressed the issue of whether working memory and inhibitory control can be dissociated, using data from a sample of patients who were recruited in a longitudinal study (Crawford et al., 2013, 2015). The first case revealed a preserved working memory capacity together with poor inhibitory control in the anti-saccade task. A longitudinal follow-up revealed that the defective inhibitory control emerged 12-months before the dementia was evident on the mini-mental state examination assessment. A second case revealed a poor working memory together with a well-preserved level of inhibitory control. The dissociation of working memory and inhibitory control was confirmed statistically in 7 additional cases. These findings yield converging evidence that working memory and inhibitory control are distinct cognitive operations and challenges the Kimberg and Farah (2000) cognitive model of working memory.

The disengagement of visual attention in Alzheimer's disease: a longitudinal eye-tracking study

INTRODUCTION

Eye tracking provides a convenient and promising biological marker of cognitive impairment in patients with neurodegenerative disease. Here we report a longitudinal study of saccadic eye movements in a sample of patients with Alzheimer's disease and elderly control participants who were assessed at the start of the study and followed up 12-months later.

METHODS

Eye movements were measured in the standard gap and overlap paradigms, to examine the longitudinal trends in the ability to disengage attention from a visual target.

RESULTS

Overall patients with Alzheimer's disease had slower reaction times than the control group. However, after 12-months, both groups showed faster and comparable reductions in reaction times to the gap, compared to the overlap stimulus. Interestingly, there was a general improvement for both groups with more accurately directed saccades and speeding of reaction times after 12-months.

CONCLUSIONS

These findings point to the value of longer-term studies and follow-up assessment to ascertain the effects of dementia on oculomotor control.

Wechsler Adult Intelligence Scale-III profile in the early stages of Alzheimer's disease: performance in subtests sensitive to and resistant to normal decline with ageing

AIM

This study examined the significance of age-related subtest scores from the Japanese version of the Wechsler Adult Intelligence Scale-III in patients in the early stages of Alzheimer's disease (AD).

METHODS

The subjects of this study included 58 elderly Japanese persons classified into two groups: AD group (n = 29) and control group (n = 29). These groups did not differ in age, years of education, gender ratio, Hasegawa's Dementia Scale-Revised score, or Full-Scale IQ score. No subject scored below the cut-off point on Hasegawa's Dementia Scale-Revised, a frequently used dementia screen test in Japan.

RESULTS

At the index score level, General Ability Index scores were the only scores that differed significantly between the groups, with the AD group scoring significantly lower than the control group (P < 0.05, Hedges' g = 0.54). At the subtest level, information scores were the only scores that differed significantly between the groups, with the AD group significantly lower than the control group (P < 0.01, Hedges' g = 0.74).

CONCLUSION

The General Ability Index is a composite score that deducts components of working memory and processing speed, which are sensitive to decline with normal ageing, from the Full-Scale IQ. It also served as a subtest measuring crystallized intelligence, especially of acquired knowledge of general and factual information. Therefore, the results of this study seem to suggest that Wechsler Adult Intelligence Scale-III profile of very early AD may be characterized by weak performance on subtests normally resistant to decline with ageing.

Understanding the Outcomes Measures used in Huntington Disease Pharmacological Trials: A Systematic Review

BACKGROUND

The identification of the gene mutation causing Huntington disease has raised hopes for new treatments to ease symptoms and slow functional decline. As such, there has been a push towards designing efficient pharmacological trials (i.e., drug trials), especially with regard to selecting outcomes measures that are both brief and sensitive to changes across the course of the disease, from subtle prodromal changes, to more severe end-stage changes.

OBJECTIVES

Recently, to aid in efficient development of new HD research studies, the National Institute of Neurological Disorders and Stroke (NINDS) published recommendations for measurement selection in HD. While these recommendations are helpful, many of the recommended measures have little published data in HD. As such, we conducted a systematic review of the literature to identify the most common outcomes measures used in HD clinical trials.

METHODS

Major medical databases, including PubMed, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials, were used to identify peer-reviewed journal articles in English from 2001 through April 2013; 151 pharmacological trials were identified.

RESULTS

The majority of HD clinical trials employed clinician-reported outcomes measures (93%); patient reported outcome measures (11%) and observer reported outcome measures (3%) were used with much less frequency.

CONCLUSIONS

We provide a review of the most commonly used measures across these trials, compare these measures to the clinical recommendations made by the NINDS working groups, and provide recommendations for selecting measures for future clinical trials that meet the Food and Drug Administration standards.

Effects of off-pump and on-pump coronary-artery bypass grafting at 1 year

BACKGROUND

Previously, we reported that there was no significant difference at 30 days in the rate of a primary composite outcome of death, myocardial infarction, stroke, or new renal failure requiring dialysis between patients who underwent coronary-artery bypass grafting (CABG) performed with a beating-heart technique (off-pump) and those who underwent CABG performed with cardiopulmonary bypass (on-pump). We now report results on quality of life and cognitive function and on clinical outcomes at 1 year.

METHODS

We enrolled 4752 patients with coronary artery disease who were scheduled to undergo CABG and randomly assigned them to undergo the procedure off-pump or on-pump. Patients were enrolled at 79 centers in 19 countries. We assessed quality of life and cognitive function at discharge, at 30 days, and at 1 year and clinical outcomes at 1 year.

RESULTS

At 1 year, there was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (12.1% and 13.3%, respectively; hazard ratio with off-pump CABG, 0.91; 95% confidence interval [CI], 0.77 to 1.07; P=0.24). The rate of the primary outcome was also similar in the two groups in the period between 31 days and 1 year (hazard ratio, 0.79; 95% CI, 0.55 to 1.13; P=0.19). The rate of repeat coronary revascularization at 1 year was 1.4% in the off-pump group and 0.8% in the on-pump group (hazard ratio, 1.66; 95% CI, 0.95 to 2.89; P=0.07). There were no significant differences between the two groups at 1 year in measures of quality of life or neurocognitive function.

CONCLUSIONS

At 1 year after CABG, there was no significant difference between off-pump and on-pump CABG with respect to the primary composite outcome, the rate of repeat coronary revascularization, quality of life, or neurocognitive function. (Funded by the Canadian Institutes of Health Research; CORONARY ClinicalTrials.gov number, NCT00463294.).

University of Kentucky Sanders-Brown healthy brain aging volunteers: donor characteristics, procedures and neuropathology

Cognitively intact elderly research volunteers at the University of Kentucky have been recruited, followed longitudinally, and autopsied with extensive neuropathological evaluations since 1989. To date, the cohort has recruited 1,030 individuals with 552 participants being actively followed, 363 deceased, and 273 autopsied. An extensive database has been constructed with continuous updates that include textured clinical, neuropsychological, neuroimaging, and pathological information. The history, demographics, clinical observations, and pathological features of this research cohort are described. We also explain some of the evolving methodologies and the academic contributions that have been made due to this motivated group of older Kentuckians.

Thyroid hormones and cognitive functioning in healthy, euthyroid women: a correlational study

Thyroid hormones (THs) play a critical role in differentiation, growth, and metabolism of animal and human organ systems, including the brain. Although associations between normal levels of THs and cognitive functions in healthy elderly individuals have been reported, the findings are inconsistent, possibly due to differences in study designs. Because thyroid disease occurs more frequently in women, the goal of the present study was to examine the relationship between levels of THs and performance on neuropsychological tests in 122 healthy, euthyroid women whose mean age was 51 years. Higher levels of free T3 were positively associated with longer completion times (slower performance) on Trail Making Test - Part A (p = 0.006) and Part B (p = 0.032) and on the Tower of London test (p = 0.002). Higher levels of thyroglobulin antibodies (TgAb) were positively correlated with more errors on the Trail Making Test Part B (p = 0.000), on the Word Fluency test (p = 0.023), and on the Design Fluency test (p = 0.045). No significant correlations between TH levels and scores on mood, verbal memory, or working memory measures were observed. The findings point to a possible link between THs and cognitive processes that are mediated primarily by frontal cortex, areas associated with executive function tasks, and suggest that elevations in levels of free T3 and TgAB within the normal range may negatively influence executive functions.

Cognitive Flexibility in the Normal Elderly and in Persons with Dementia as Measured by the Written and Oral Trail Making Tests

This study investigated cognitive flexibility as indexed by the Written and Oral Trail Making Test (TMT) in sixteen persons with dementia and 60 normal elderly. Written and Oral TMT performances were significantly correlated with each other and with other tests of cognitive flexibility providing an index of the convergent construct validity of these tests. Part B of the Written TMT was influenced by psychomotor ability although this was diminished by the use of a ratio score B/A rather than simply Part B performance. The Oral test was not related to visual or motor skills, providing evidence for its divergent validity. Both parts of the Written and Oral TMT were found to be sensitive to cognitive decline in dementia. Performance on both Oral and Written TMT was also influenced by age, gender, education and intellectual ability. Previous norms (e.g., MOANS) for the Written TMT which are based on relatively educated elderly, tended to provide deflated scores for the community group tested here. Some additional, preliminary normative data for both tests were compiled which take into account the influences of each of these variables.

Comparison between the story recall test and the word-list learning test in Korean patients with mild cognitive impairment and early stage of Alzheimer's disease

Among verbal memory tests, two that are commonly used to measure the ability of verbal memory function in cognitive impairment are story recall tests and word-list learning tests. However, research is limited regarding which test might be more sensitive in discriminating between normal cognitive aging and patients with Alzheimer's disease (AD) in the Korean population. The purpose of the current study was to compare the word-list learning test (Seoul Verbal Learning Test; SVLT) and the story recall test (Korean Story Recall Test; KSRT) to determine which test is more sensitive in discriminating between individuals with normal cognitive aging and patients with mild cognitive impairment (MCI) and early stage of AD in Korea. A total of 53 healthy adults, 127 patients with MCI, and 72 patients with early stage of AD participated in this study. The receiver-operating characteristic (ROC) curve and area under the curve (AUC) were evaluated to compare these two tests. The results showed that the AUC of the SVLT was significantly larger than the AUC of the KSRT in all three groups (healthy adults vs. MCI and early stage of AD; healthy adults vs. MCI; healthy adults vs. early stage of AD). However, in comparison of patients with MCI and early stage of AD, the AUC of SVLT and the AUC of KSRT were not significant. The word-list learning test is a more useful tool for examining verbal memory function for older adults in Korea than the story recall test.

Spanish translation and adaptation of the repeatable battery for the assessment of neuropsychological status (RBANS) Form A in a pilot sample

INTRODUCTION

RBANS is a short neuropsychological battery which has shown to be sensitive in detecting cognitive impairment in degenerative and non-degenerative diseases. It has been translated and adapted to different languages and is widely used in other countries, but no Spanish version has been published. The objective was to make a valid translation of the RBANS to Spanish, and obtain a version adapted to the Spanish population.

PATIENTS AND METHODS

The study included 73 subjects: 25 males with a mean age of 54 years and 9.72 years of education, and 48 females with a mean age of 53 years and 10.29 years of education. The battery was translated using the translation-back-translation method (with slight differences), followed by a descriptive pilot study in a sample of the normal population.

RESULTS

An overall reliability coefficient with a Cronbach alpha of 0.73 was obtained in the translation and adaptation of the RBANS, Form A (1998). Statistically significant positive correlations between the indices were obtained.

CONCLUSIONS

The version translated and adapted to Spanish performs similarly to the original version.

Neuropsychological assessment of fitness to drive following acquired cognitive impairment

PRIMARY OBJECTIVE

The study evaluated a neuropsychological assessment battery used to assess fitness to drive in cognitively impaired individuals and hypothesized that the battery would be associated with on-road outcome measures. A secondary aim was to explore the relationships between individual neuropsychological tests and driving performance.

RESEARCH DESIGN

The study used a cross-sectional design in which a sample of individuals with various types of cognitive impairment completed the test battery and an on-road driving test.

METHODS AND PROCEDURES

Performance on the test battery was compared to on-road driving performance in 104 individuals with acquired cognitive impairment.

MAIN OUTCOMES AND RESULTS

The battery had 73% sensitivity and 76% specificity in terms of agreement with the 'pass/fail' classification of the on-road driving test. Scores on the battery accounted for 18% of the variance in the total number of corrective interventions performed by a driving instructor during the on-road test. Most tests correlated significantly with driving test outcomes. While one test, the Rey Complex Figure Test, emerged as an independent predictor of driving performance in multiple regression analyses, the variance explained by this single test was small.

CONCLUSIONS

The results provide support for the use of a battery approach to assess fitness to drive.

A systematic review of the reliability of screening for cognitive impairment in older adults by use of standardised assessment tools administered via the telephone

We conducted a systematic review to identify the extent to which the process of screening for cognitive impairment in older adults has been validated for administration by telephone. A search of electronic databases and a handsearch of relevant journals and reference lists were carried out for studies published between 1966 and 2008. The database search identified 411 studies and handsearching found another seven. Fourteen studies were finally identified as relevant to the review: three concerned a modified telephone version of the Mini-Mental State Examination (MMSE); five concerned the Telephone Interview for Cognitive Status; one study tested a telephone-administered Short Portable Mental Status Questionnaire; four studies tested the validity of newly developed tools; and the remaining study considered the Confusion Assessment Method as a means of diagnosing delirium. The quality of the reference standard varied among the papers reviewed. The limited number of high quality studies with suitable reference standards makes it difficult to recommend a specific tool which should be used to assess the cognition of older adults by telephone. In advance of further studies, the 22-item MMSE is simple to administer and was shown to correlate well with the face-to-face MMSE. It appears to be a useful technique for telephone screening for cognitive impairment or delirium, if used in conjunction with the Delirium Symptom Interview.

Concordance rates for cognitive impairment among older African American twins

BACKGROUND

There is significant attention to the growing elderly African American population and estimating who and how many within this population will be affected by cognitive impairment.

OBJECTIVE

The etiology of cognitive impairment has not been well studied in African Americans and the contribution of genetic and environmental influences to cognitive impairment is not clear.

METHODS

We calculated concordance rates and heritability for cognitive impairment in 95 same-sexed pairs of African American twins from the Carolina African American Twin Study on Aging (CAATSA). The sample had an average age of 59.6 years (SD = 8.6 years, range 50-88 years) and 60% were female. The Telephone Interview for Cognitive Status (TICS) was used to assess cognitive impairment with a lower cutoff based on our previous research with African Americans.

RESULTS

Thirteen of the monozygotic (MZ) twins (30.2%) and 9 of the dizygotic (DZ) twins (17.3%) were cognitively impaired. The concordance rate was 72% for MZ and 45% for DZ. We found the heritability for cognitive impairment to be 54%.

CONCLUSIONS

The study findings indicate that cognitive impairment is highly heritable, suggesting that genetics may play a relatively large role in the development of cognitive impairment in African American twins.

Neuropsychological assessment of dementia

Neuropsychological studies show that cognitive deficits associated with Alzheimer's disease (AD) are distinct from age-associated cognitive decline. Quantitative and qualitative differences are apparent across many cognitive domains, but are especially obvious in episodic memory (particularly delayed recall), semantic knowledge, and some aspects of executive functions. The qualitatively distinct pattern of deficits is less salient in very old AD patients than in younger AD patients. Although decline in episodic memory is usually the earliest cognitive change that occurs prior to the development of the AD dementia syndrome, asymmetry in cognitive abilities may also occur in this "preclinical" phase of the disease and predict imminent dementia. Discrete patterns of cognitive deficits occur in AD and several neuropathologically distinct age-associated neurodegenerative disorders. Knowledge of these differences helps to clinically distinguish among various causes of dementia and provides useful models for understanding brain-behavior relationships that mediate cognitive abilities affected in various neurodegenerative diseases.

Clinical features of MCI: motor changes

Mild cognitive impairment (MCI) is a classification reserved for nondemented elderly individuals at increased risk for future decline to dementia, compared to those with normal cognition. Cognitive tests, particularly those assessing verbal recall, have been found to be useful in the identification of elderly people with MCI. We argue that a variety of motor/psychomotor evaluations are also sensitive to MCI. Motor assessments described as complex correctly categorize normal versus MCI elderly with comparable accuracies to those obtained by cognitive tests. Unlike performance on verbally based cognitive measures, motor-test scores appear to be relatively independent of educational attainment, indicating that the use of certain motor tests may be particularly valuable in the identification of MCI among elderly with widely varying educational backgrounds.

Objective metamemory testing captures awareness of deficit in Alzheimer's disease

For reasons that remain unknown, there is marked inter-person variability in awareness of episodic memory loss in patients with Alzheimer's disease (AD). Existing research designs, primarily subjective in nature, have been at a relative disadvantage for evaluating disordered metamemory and its relation to the clinical and neuropathological heterogeneity of AD, as well as its prognosis for various disease outcomes. The current study sought to establish an objective means of evaluating metamemory in AD by modifying traditional metacognitive paradigms in which participants are asked to make predictions regarding their own memory performance. Variables derived from this measure were analyzed in relation to clinically rated awareness for memory loss. As predicted, a range of awareness levels existed across patients with mild to moderate AD (n=24) and clinical ratings of awareness (CRA) were significantly associated with verbal episodic memory monitoring (r = .46, p = .03). Further, patients who were rated as aware of their memory loss remained well calibrated over the course of the task whereas those rated as relatively unaware grew over-confident in their predictions [F (1, 33) = 4.19, p = .02]. Findings suggest that over-confidence may be related to impaired online error recognition and compromised use of metamemory strategies such as the Memory for Past Test (MPT) heuristic. Importantly, clinically rated awareness did not vary as a function of demographic variables, global cognition, or verbal memory. However, participants characterized as relatively unaware were impaired on a nonverbal memory task as compared to aware participants [F (1, 20) = 6.98, p = .02]. The current study provides preliminary support for the use of a recognition-based verbal episodic memory monitoring task as a quantitative measure of awareness for memory loss in AD, and offers insight into the manner in which metamemory breaks down. Discrepancies in nonverbal memory across the two awareness groups provide preliminary support for the idea that metamemory variability in AD may be related to the neuroanatomic presentation of the disease, with disordered awareness potentially reflective of a critical level of right hemisphere involvement.

Early detection of risk of onset for dementia of the Alzheimer type and subtle executive dysfunction after TBI using the test of verbal conceptualization and fluency during clinical neuropsychological assessment: two case studies

Two case reports are presented that illustrate the use of a new assessment instrument of executive skills, the Test of Verbal Conceptualization and Fluency (TVCF), as a component of a clinical neuropsychological assessment. The cases presented include the assessment of a patient at risk of developing Alzheimer's disease and a patient with subtle signs of executive dysfunction subsequent to a mild head injury. Both patients had high levels of education and occupational status. The TVCF demonstrated clinical sensitivity to central nervous system (CNS) insult and results similar to those obtained with other established measures of executive functioning.

Assessment of information processing in working memory in applied settings: the paper and pencil memory scanning test

BACKGROUND

Sternberg's Memory Scanning Test (MST) is a useful paradigm for evaluating the speed and efficiency of information processing in working memory. Unfortunately, the classical MST has major drawbacks for use in applied settings such as the clinic. For example, its administration time is long and the test is too difficult for older people or people with cognitive disorders. It would be advantageous to have a test for the assessment of information processing in working memory for use in applied settings, for example in differential diagnostics in clinical settings.

METHOD

The MST was modified into a format that makes it more appropriate for use in the clinic, the Paper & Pencil MST (P&P MST). The influence of age and age-extrinsic factors on the P&P MST was evaluated in a large sample (n=1839) of healthy and cognitively intact adults (24-81 years) to establish the normal range of performance.

RESULTS

Age and education affected all components of information processing in working memory. Gender did not affect the non-memory processing stages in the P&P MST, but affected the speed of memory scanning. An Age x Gender interaction was observed, which suggested that females who were aged below 55 scanned working memory faster than males, and vice versa for people aged above 55.

CONCLUSIONS

The established P&P MST norms provide a useful tool in applied settings when a person's memory scanning and non-memory processes in working memory are to be evaluated.

Effects of sex and APOE epsilon4 on object recognition and spatial navigation in the elderly

To determine effects of APOE epsilon4 (epsilon4) on cognitive performance of healthy elderly, 116 nondemented elders (mean age 81 years) were cognitive tested. The established tests Faces, Family Pictures, Spatial Span Forward and Backward, and the object recognition and spatial navigation tests developed in our laboratory were used as cognitive tests. Salivary samples were collected to determine APOE genotype and salivary testosterone and cortisol levels. Non-epsilon4- and epsilon4-carrying men and women did not differ in age, Mini-Mental State Examination, Wide Range Achievement Test-Reading, Beck Anxiety Inventory, or reaction time scores. There was an effect of epsilon4 on the object recognition and spatial navigation tests, with non-epsilon4 carriers outperforming epsilon4 carriers, but not in the other cognitive tests. No relationship was found for sex and epsilon4 status or sex and performance during the hidden session of Memory Island. In men, salivary cortisol levels correlated with object recognition. These results show that object recognition and spatial navigation tests are useful to assess cognitive function in the elderly.

The Placing Test: Preliminary Investigations of a Quick and Simple Memory Test Designed to be Sensitive to Pre-dementia Alzheimer's Disease but not to Normal Ageing

The medial temporal lobe (MTL) memory system is damaged early in Alzheimer's disease. Cognitive tests designed to help diagnose the disease must detect dysfunction in this system, but must also be insensitive to the cognitive slowing that characterizes normal ageing. On the assumption that the MTL system forms new memories by binding together the many informational aspects of events into units, The Placing Test was designed to index this function by measuring the ability to remember associations between faces and their locations. The influence of normal ageing was minimized by using procedures that compensate for the difficulties in learning and retrieval caused by the cognitive slowing of normal ageing. In two experiments The Placing Test was administered as part of a battery of neuropsychological tests to a group of healthy older people. In both studies, performance in The Placing Test correlated significantly with other measures of memory, but had weaker associations than standard memory measures with other types of cognitive function. The Placing Test appeared not to be biased by age, education or gender, although a larger sample is needed to verify this. A final study examined the performance of 16 patients with suspected Alzheimer's disease. These patients showed clear impairment in The Placing Test, with 81% scoring below the 5th percentile, despite the majority having normal MMSE scores. It is concluded that The Placing Test provides a quick, simple and sensitive measure of memory that has potential to be useful in routine diagnostic investigations for Alzheimer's disease.

Semantic memory deficits in low-educated patients with Alzheimer's disease

BACKGROUND/PURPOSE

Although a deficit of semantic memory is evident in the dementia of the Alzheimer's type (DAT), the underlying neuropsychologic mechanism remains controversial. Breakdown of the semantic network during the course of DAT and an inability to access semantic information have been postulated as possible explanations, but supporting data are limited, particularly in low-educated patients. This study examined semantic memory in low-educated patients with different degrees of dementia severity.

METHODS

In total, 197 adult subjects were recruited, including 165 DAT patients and 32 normal controls. Subjects were divided into four subgroups according to their dementia severity. All subjects completed an episodic memory task, the Six-Object Memory Test, and semantic memory tasks including the Object Naming Test, the Remote Memory Test and the Semantic Association of Verbal Fluency Test. One-way ANOVA and ANCOVA with a post hoc Scheffe's procedure were used to evaluate differences between groups.

RESULTS

All patients, irrespective of the degree of dementia, showed impaired performance on the Six-Object Memory Test [F (4, 163) = 69.95, p < 0.0001 for immediate recall; F (4, 163) = 41.34, p < 0.0001 for delayed recall]. On the semantic memory tasks, patients with moderate to severe dementia showed impaired performances on the Object Naming Test [F (4, 180) = 28.25, p < 0.0001] and the Remote Memory Test [F (4, 167) = 26.22, p < 0.0001 for recall; F (4, 167) = 34.80, p < 0.0001 for recognition], while all patients performed defectively on the Semantic Association of Verbal Fluency Test [F (4, 194) = 70.43, p < 0.0001].

CONCLUSION

Our results thus partially support the hypotheses that a loss of semantic structure and an inability to access semantic knowledge occur in the pathogenesis of DAT.

Divergent thinking in Alzheimer's and frontotemporal dementia

Twenty-three patients with mild dementia of the Alzheimer's type (DAT) or frontotemporal type (DFT) and age- and education-matched control subjects were administered tests of complex fluency involving divergent thinking and tests of letter, category, and figural fluency. The tests of complex fluency discriminated the dementia patients from control subjects more strongly than did the other fluency tests. The results suggest that divergent thinking as assessed by complex fluency tests is a cognitive domain that is impaired early in the course of dementia. The sensitivity of complex fluency tests compared to that of letter, category, and figural fluency tests may be related to greater demands for conceptualization in relating stimulus attributes to function and greater demands for flexible thinking during self-directed search processes.

National Institute of Neurological Disorders and Stroke-Canadian Stroke Network vascular cognitive impairment harmonization standards

BACKGROUND AND PURPOSE

One in 3 individuals will experience a stroke, dementia or both. Moreover, twice as many individuals will have cognitive impairment short of dementia as either stroke or dementia. The commonly used stroke scales do not measure cognition, while dementia criteria focus on the late stages of cognitive impairment, and are heavily biased toward the diagnosis of Alzheimer disease. No commonly agreed standards exist for identifying and describing individuals with cognitive impairment, particularly in the early stages, and especially with cognitive impairment related to vascular factors, or vascular cognitive impairment.

METHODS

The National Institute for Neurological Disorders and Stroke (NINDS) and the Canadian Stroke Network (CSN) convened researchers in clinical diagnosis, epidemiology, neuropsychology, brain imaging, neuropathology, experimental models, biomarkers, genetics, and clinical trials to recommend minimum, common, clinical and research standards for the description and study of vascular cognitive impairment.

RESULTS

The results of these discussions are reported herein.

CONCLUSIONS

The development of common standards represents a first step in a process of use, validation and refinement. Using the same standards will help identify individuals in the early stages of cognitive impairment, will make studies comparable, and by integrating knowledge, will accelerate the pace of progress.

Design fluency in dementia of Alzheimer's type, multi-infarct dementia and dementia associated with alcoholism

Design fluency was assessed in four age and education matched groups 16 medical controls, 17 dementia of the Alzheimer's type (DAT), 15 multi-infarct dementia (MID) and six patients with dementia associated with alcoholism (DAA). In comparison with the control group, the three dementia groups distinctly demonstrated impaired production of novel designs with a significant tendency towards perseveration. Also the four groups were assessed on word fluency, with similar findings obtained. Word fluency and design fluency performance was most interrelated within the DAT group. Although the nonspecific effects of the dementing process in each group contributed to impaired design fluency production, in the DAT group it appeared that visuoconstructive deficits, in particular, negatively impacted design fluency. Results are discussed in terms of the clinical utility of the design fluency measure and its relationship to impaired novel and creative responding in dementia.

Performance on neurocognitive tests by co-twins to dementia cases compared to normal control twins

Nondemented co-twins of twins who were diagnosed as demented were compared to randomly selected members of normal control twin pairs in which both members of the pair were nondemented. Nondemented co-twins included 23 monozygotic and 62 dizygotic twins; there were 27 normal control twins. Both monozygotic and dizygotic nondemented co-twins of dementia cases scored significantly lower than normal control twins on 5 of 10 cognitive tests. Moreover, monozygotic co-twins of dementia cases had a generally lower score profile than dizygotic co-twins of dementia cases did. These findings show that being at greater genetic risk for dementia is reflected in cognitive performance even in the absence of a diagnosis of dementia.

Extending neuropsychological assessments into the primary mental ability space

A battery of 17 neuropsychological tests (including the CERAD battery) and 17 psychometric ability tests were administered to a sample of 499 participants of the Seattle Longitudinal study who had been given the psychometric ability tests seven and 14 years earlier. The neuropsychological tests were projected into a 5-factor psychometric ability space by means of extension analysis. The concurrent regressions of the neuropsychology tests on the psychometric ability tests were then used to estimate neuropsychology test scores from the psychometric ability tests administered in 1984, 1991 and 1998. Neuropsychologists then rated the study participants as either normal, suspect or cognitively impaired in 1998. Changes in estimated test scores were computed over seven and fourteen years. Significant odds ratios between normal and cognitively impaired groups were found for all neuropsychological tests over the proximal period and for most tests over the 14-year period. Similar findings occurred for the odds ratios between the normal and suspect groups for the most proximal 7-year changes.

Inhibitory control of saccadic eye movements and cognitive impairment in Alzheimer's disease

BACKGROUND

This study examined the relationship of inhibitory control and measures of neuropsychological impairment in patients with early Alzheimer's disease (AD). Four specific questions were addressed: 1) Which error parameters of saccadic inhibition are sensitive to AD? 2) Which inhibitory deficits are related to cognitive measures of impairment? 3) Is the inhibitory impairment in AD dependent on the initiation of a volitional eye movement? 4) How do the effects of saccadic inhibitory control in AD relate to the normal effects of aging?

METHODS

Eighteen patients with probable AD and two control groups (seventeen young, and eighteen old participants) completed a battery of neuropsychological tests and four saccadic eye movement paradigms: pro-saccade, NO-GO, GO/NO-GO and anti-saccade.

RESULTS

Old controls generated increased inhibition errors in comparison to young controls in the GO/NO-GO paradigm. In comparison to old controls, AD generated normal saccades in the pro-saccade paradigm, but showed a higher proportion of inhibition errors in the NO-GO, GO/NO-GO and anti-paradigms. The frequency of uncorrected errors in the anti-saccade paradigm was positively correlated with cognitive measures of dementia.

CONCLUSIONS

AD patients have an impairment of inhibitory control and error-correction that exceeds the effects of normal aging and is related to the severity of dementia. However, the inhibitory impairment is not contingent on the interaction with a volitional saccade.

Differential effects of everyday stress on the episodic memory test performances of young, mid-life, and older adults

This research explored the differential association of everyday stress with the episodic memory test performances of young, mid-life, and older adults. Participants included 98 community-dwelling adults ranging in age from 19-89 years. Everyday stress was assessed via the Perceived Stress Scale and the Elder Life Stress Inventory. A brief battery of episodic memory tasks was administered which included tests of Logical Memory, Verbal Paired Associates, Digit Symbol Substitution, and Digit Symbol Incidental Learning. Results suggest that everyday hassles and irritations as well as the accumulation of challenging life events may exacerbate age-related decline on episodic memory tests that require greater executive resources and more integrated and elaborative processing. The functional relationship between affective status and risk for dementia is discussed, and consideration of individual differences in everyday stress is suggested so as to allow more sensitive interpretation of episodic memory tests commonly used to discern mild cognitive impairment.