Differential verbal fluency deficits in the preclinical stages of Alzheimer's disease and vascular dementia

Word Fluency Test (WFT): A parallel FAS alternative

The capacity to quickly verbalize words beginning with a specific letter is integral in assessing language skills as well as an essential part of a comprehensive neuropsychological assessment. Using the letters F, A, S as a word fluency measure is limited by having no direct parallel alternative that can use the same F, A, S norms. This observational and cross-sectional study examined the correlation between the Word Fluency Test (WFT), utilizing letters M, D, H, as a parallel alternative to the clinical standard F, A, S to determine if the two are equivalent. This would allow for the use of existing F, A, S norms. Study participants (N = 356) were comprised of both adult control participants and out-patients with normal neuropsychological test results. Between-group differences for both task performances were not statistically significant indicating that patients and controls performed similarly on each of the six letters. Between-letter correlations were moderate in strength indicating an acceptable level of agreement between all of the letters. The results confirm equivalency and support administering the WFT and employing F, A, S norms offering a corresponding parallel alternative measure with strong correlation indicating high level of agreement.

The NeuroBel: A Screening Test for Verbal Language Impairment in Spanish-Speaking Elderly People With Cognitive Decline

PURPOSE

The NeuroBel is a short test that can detect cognitive decline using language tasks. This study replicated previous research using larger clinical samples from three Spanish-speaking countries.

METHOD

Eight tasks were used to analyze verbal language functioning using a psycholinguistic approach. A total of 232 elderly, monolingual Spanish speakers from Spain, Cuba, and Colombia participated in this study. Of these, 76 had Alzheimer's disease (AD) in the initial phase, 75 had mild cognitive impairment (MCI), and 81 did not exhibit cognitive impairment (healthy controls).

RESULTS

Significant differences were observed among the three clinical groups. The participants with AD and the participants with MCI had significantly lower NeuroBel scores than the control group on most of the tasks. However, repetition (in AD vs. MCI) and auditory lexical decision (in MCI vs. control) tasks were not significant in Tukey's post hoc tests. Discriminant analysis showed that 80.6% of the participants were correctly classified into the original groups and revealed the tasks that were the best and worst for differentiating among groups. The receiver-operating characteristic curves showed high sensitivity for AD and MCI. The area under the curve was .97 in the contrast of AD versus MCI + controls, .96 in the determination of overall cognitive decline (AD + MCI vs. controls), and .93 in the contrast of MCI and control groups.

CONCLUSION

This study confirmed that the NeuroBel is a suitable test for detecting cognitive decline based on language impairment in Spanish-speaking elderly people.

Current Understanding of Verbal Fluency in Alzheimer's Disease: Evidence to Date

Since their development, verbal fluency tests (VFTs) have been used extensively throughout research and in clinical settings to assess a variety of cognitive functions in diverse populations. In Alzheimer's disease (AD), these tasks have proven particularly valuable in identifying the earliest forms of cognitive decline in semantic processing and have been shown to relate specifically to brain regions associated with the initial stages of pathological change. In recent years, researchers have developed more nuanced techniques to evaluate verbal fluency performance, extracting a wide range of cognitive metrics from these simple neuropsychological tests. Such novel techniques allow for a more detailed exploration of the cognitive processes underlying successful task performance beyond the raw test score. The versatility of VFTs and the richness of data they may provide, in light of their low cost and speed of administration, therefore, highlight their potential value both in future research as outcome measures for clinical trials and in a clinical setting as a screening measure for early detection of neurodegenerative diseases.

Validity of the Brief Assessment of Impaired Cognition case-finding instrument for identification of dementia subgroups and staging of dementia

BACKGROUND AND PURPOSE

The aims of this study were to examine the psychometric properties of the Brief Assessment of Impaired Cognition (BASIC) case-finding instrument in clinical settings focusing on (i) test-retest reliability, (ii) the discriminative validity of BASIC and its components for identification of Alzheimer disease (AD) dementia and non-AD dementia, and (iii) the association of expert clinical rating of cognitive status with BASIC performance.

METHODS

The test-retest reliability analysis was based on a sample of general practice patients (n = 59) retested with a mean interval of 19 days. Discriminative validity analyses and analysis of the association of cognitive status with BASIC performance were based on data from the primary validation study of BASIC in memory clinics.

RESULTS

The test-retest reliability of BASIC was high (r = 0.861). No significant difference in discriminative validity was found for identification of AD dementia (sensitivity = 0.99, specificity = 0.98) and non-AD dementia (sensitivity = 0.90, specificity = 0.98). All components of BASIC contributed to the high discriminative validity of both AD and non-AD dementia. BASIC performance was significantly correlated with expert clinical rating of the cognitive status of patients. A crude staging model for cognitive status using BASIC score intervals had superior classification accuracy (70%) compared to a Mini-Mental State Examination (MMSE) score range-based model (58% accuracy).

CONCLUSIONS

BASIC is a reliable and valid case-finding instrument for AD dementia and non-AD dementia in clinical settings. BASIC performance is significantly associated with the degree of cognitive impairment, and BASIC seems to be superior to MMSE for staging of impairment.

Neuropsychological findings in migraine: a systematic review

ABSTRACT. Patients with migraine often experience cognitive dysfunction during a migraine attack, but they have also been reported to complain about cognitive impairment after an attack and during the interictal period. Objective: The aim of this study was to determine what neuropsychological test methods are used to assess cognitive functioning in migraine patients and to examine the neuropsychological findings in adult (≥18 years) migraineurs compared to adult (≥18 years) healthy controls (HC). Methods: A systematic review was conducted on the literature published between 2012 and the present. The search results were screened and additional studies identified in the lists of references in the selected articles. A total of 16 articles met the inclusion criteria. Results: The 16 articles included in the review compared chronic migraineurs (CM), migraineurs with (MwA) and without aura (MwoA), and migraineurs without aura classification (MIG) to HC. A total of 45 neuropsychological assessment methods were identified. CM and MwA were found to perform significantly worse than HC in executive function, attention, and visual functioning. Additionally, both MwA and MwoA performed significantly worse than HC in memory functions. CM and both MwA and MwoA also performed significantly worse than HC in general cognitive functioning. Surprisingly, MIG performed significantly better than HC in several cognitive domains, including executive, motor, and language functioning and general cognitive functioning. Conclusions: This systematic review mostly concurs with the results of an earlier systematic review on the topic from 2012, but with the important addition that different migraine diagnostic groups should be assessed separately.

A comparison of techniques for deriving clustering and switching scores from verbal fluency word lists

Objective

To compare techniques for computing clustering and switching scores in terms of agreement, correlation, and empirical value as predictors of incident cognitive impairment (ICI).

Methods

We transcribed animal and letter F fluency recordings on 640 cases of ICI and matched controls from a national epidemiological study, amending each transcription with word timings. We then calculated clustering and switching scores, as well as scores indexing speed of responses, using techniques described in the literature. We evaluated agreement among the techniques with Cohen’s κ and calculated correlations among the scores. After fitting a base model with raw scores, repetitions, and intrusions, we fit a series of Bayesian logistic regression models adding either clustering and switching scores or speed scores, comparing the models in terms of several metrics. We partitioned the ICI cases into acute and progressive cases and repeated the regression analysis for each group.

Results

For animal fluency, we found that models with speed scores derived using the slope difference algorithm achieved the best values of the Watanabe–Akaike Information Criterion (WAIC), but with good net reclassification improvement (NRI) only for the progressive group (8.2%). For letter fluency, different models excelled for prediction of acute and progressive cases. For acute cases, NRI was best for speed scores derived from a network model (3.4%), while for progressive cases, the best model used clustering and switching scores derived from the same network model (5.1%). Combining variables from the best animal and letter F models led to marginal improvements in model fit and NRI only for the all-cases and acute-cases analyses.

Conclusion

Speed scores improve a base model for predicting progressive cognitive impairment from animal fluency. Letter fluency scores may provide complementary information.

Insomnia symptom subtypes and manifestations of prodromal neurodegeneration: a population-based study in the Canadian Longitudinal Study on Aging

STUDY OBJECTIVES

To identify the association between insomnia symptoms and signs of prodromal neurodegeneration, including an analysis of potential differences between sleep-onset and sleep-maintenance insomnia.

METHODS

We included those aged 45-85 years, living in 1 of 10 Canadian provinces between 2012 and 2015 (at the baseline), recruited via 3 population-based sampling methods. Insomnia symptoms were assessed using questions adapted/modified from the Pittsburgh Sleep Quality Index. A panel of potential prodromal neurodegenerative markers including self-reported symptoms and objective gait motor, cognitive, and autonomic variables were assessed cross sectionally. We compared those who endorsed insomnia symptoms ≥ 3 times per week to controls, adjusting for age, sex, and education via logistic regression.

RESULTS

Overall, 2,051/30,097 people screened positive for sleep-onset insomnia alone and 4,333 for sleep-maintenance insomnia alone, while 2,371 endorsed both subtypes. On objective gait tests, participants with sleep-onset insomnia, but not sleep-maintenance insomnia, had worse balance (odds ratio [OR] = 1.33, 95% confidence interval = [1.16, 1.52]) and slower gait speed (OR = 1.52 [1.34, 1.73]). Although participants with any insomnia subtype endorsed more motor symptoms, these were more severe in those with sleep-onset insomnia (OR onset vs maintenance = 1.13 [1.07, 1.18]). On objective cognitive tests, those with sleep-maintenance insomnia scored normally. However, participants with sleep-onset insomnia performed worse on tests of verbal fluency (OR = 1.24 [1.06, 1.43]), immediate memory (OR = 1.23 [1.08, 1.41]), and prospective memory task (OR = 1.29 [1.11, 1.50]). The sleep-onset insomnia group also had lower heart rate variability (OR = 1.23 [1.07, 1.43]). Secondary analyses found generally similar results in young vs older age of insomnia development.

CONCLUSIONS

Compared to maintenance insomnia, those with sleep-onset insomnia have more motor, cognitive, and autonomic signs/symptoms. When evaluating neurodegenerative risk, differentiating insomnia subtypes may increase precision.

CITATION

Yao CW, Pelletier A, Fereshtehnejad S-M, Cross N, Dang-Vu T, Postuma RB. Insomnia symptom subtypes and manifestations of prodromal neurodegeneration: a population-based study in the Canadian Longitudinal Study on Aging. J Clin Sleep Med. 2022;18(2):345-359.

Verbal Fluency Tasks: Influence of Age, Gender, and Education and Normative Data for the Spanish Native Adult Population

OBJECTIVE

Phonological and semantic verbal fluency (VF) tasks are frequently used to assess language and executive functions in both clinical and research settings. F, A, and S are the most commonly used letters in phonological tasks across languages and cultures. Unfortunately, the lack of norms for the native Spanish population for these letters, and for certain semantic categories such as "proper names," may lead to misinterpretation of scores due to demographic differences. The aim of the present study was to provide normative data for F, A, and S and for "proper names," "animals," and "fruits and vegetables" for the native Spanish population.

METHOD

257 healthy subjects took part in the study (ages: 17-100 years, 3-20 years of education). Correlation, multiple regression, and t-tests were used to select the most appropriate variables for stratification.

RESULTS

Education was the best predictor of performance in all tasks, followed by age. Given that t-test results showed no differences related to gender, with the only exception of the semantic category "animals," this variable was not considered for stratification. Consequently, the data were stratified in two education levels (<13, ≥13 years of education) and in two age levels (<60, ≥60) within the low-educational level group. Mean, standard deviation, and percentile scores for each group are provided.

CONCLUSIONS

The present norms provide a reference for clinicians assessing VF. This data may also facilitate comparisons with other normative studies in cross-cultural and cross-linguistic research.

Association between coronary artery calcification and cognitive function in a Chinese community-based population

Background

Coronary atherosclerosis and cognitive impairment are both age-related diseases, with similar risk factors. Coronary artery calcium (CAC), a marker of coronary atherosclerosis, may play a role in early detection of individuals prone to cognitive decline. This study aimed to investigate the relationship between CAC and cognitive function, and the capability of CAC to identify participants with a high risk of dementia in a Chinese community-based population.

Methods

A total of 1332 participants, aged 40−80 years and free of dementia from a community located in Beijing were included. All participants completed neurocognitive questionnaires and noncontrast CT examinations. Cognitive performance tests (including verbal memory, semantic fluency, executive function, and global cognitive function tests), the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CIDE) risk score, and the CAC score (CACS) were evaluated by questionnaires and CT. A CAIDE score ≥ 10 was considered to indicate a high risk of dementia in late-life. Participants were divided into three groups according to CACS (0, 1−399, ≥ 400).

Results

After adjusting for risk factors, CACS was significantly associated with verbal memory (r = −0.083, P = 0.003) and global cognitive function (r = −0.070, P = 0.012). The prevalence of a high risk of dementia in the subgroups of CACS = 0, 1−399, and ≥ 400 was 4.67%, 13.66%, and 24.79%, respectively (P < 0.001). Individuals with CACS ≥ 400 had a higher risk of CAIDE score ≥ 10 [OR = 2.30 (1.56, 4.56), P = 0.014] than those with CACS = 0. The receiver-operating characteristic curves showed that the capability of CACS to identify participants with a high risk of dementia was moderate (AUC = 0.70, 95% CI: 0.67−0.72,P < 0.001).

Conclusions

CAC, a marker of subclinical atherosclerosis, was significantly associated with cognitive performance in verbal memory and global cognitive function. CAC had a moderate capability to identify participants with a high risk of dementia, independent of age, education, and other risk factors.

Anemia and Cognitive Performance in the ELSA-Brasil Cohort Baseline

OBJECTIVE

The association between cognitive performance and hemoglobin concentration has long been a topic of debate, but few data for middle-aged persons have been explored. The authors examined the association between anemia and cognitive performance at baseline assessment in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter cohort study of individuals from six Brazilian cities.

METHODS

A total of 13,624 participants (mean age=51.6 years [SD=9.0]) were included in this cross-sectional study. Cognitive performance was evaluated by using standardized scores for verbal learning, late recall, word recognition, a semantic verbal fluency test, and the Trail-Making Test, Part B (TMT-B). The association between anemia and cognitive performance was examined by using linear regression models adjusted for sociodemographic characteristics and cardiovascular risk factors.

RESULTS

Anemia was diagnosed in 713 (5.2%) participants. No association was found between anemia and worse cognitive performance for the main models. Global cognitive scores were similar between participants with and without anemia in adjusted models for the entire sample (β=-0.004; 95% CI=-0.052, 0.044) or for men (β=0.047; 95% CI=-0.053, 0.146) and women (β=-0.015; 95% CI=-0.070, 0.040) separately. In addition, hemoglobin levels (in quintile groups) were not associated with global cognitive scores. Similarly, no significant associations with anemia or hemoglobin levels were observed when each cognitive performance test was evaluated separately.

CONCLUSIONS

Anemia and hemoglobin levels were not associated with worse cognitive performance in this large cohort.

Subtle Thyroid Dysfunction Is Not Associated with Cognitive Decline: Results from the ELSA-Brasil

BACKGROUND

Subtle thyroid alterations have a controversial role in cognition.

OBJECTIVE

We investigated the longitudinal association of baseline thyroid function, thyrotropin (TSH), and thyroxine (FT4) levels with cognitive performance after 4 years of follow-up in middle-aged and older adults without overt thyroid dysfunction.

METHODS

We included 4,473 individuals, age≥55 years at the second study wave, without overt thyroid dysfunction at baseline. Individuals were divided according to thyroid function and TSH and FT4 tertiles. Cognition was assessed at baseline and after 4 years of follow-up by the word recall (DWR), semantic verbal fluency (SVF), and trail making (TMT) tests. The longitudinal association of thyroid function and TSH and FT4 tertiles with cognitive performance was investigated using generalized estimating equations adjusted for sociodemographic characteristics, lifestyle, cardiovascular risk factors and depression.

RESULTS

There was no longitudinal association of thyroid function and TSH and FT4 baseline levels with performance on the cognitive tests. However, there was a baseline cross-sectional U-shaped association of FT4 tertiles with poorer performance in the SVF (first FT4 tertile: β= -0.11, 95% CI = -0.17; -0.04; third FT4 tertile: β= -0.10, 95% CI = -0.17; -0.04) and of the third FT4 tertile with poorer performance in the DWR (β= -0.09, 95% CI = -0.16; -0.02).

CONCLUSION

Thyroid function and hormone levels were not associated with cognitive decline during 4 years of follow-up in middle-aged and older adults without overt thyroid dysfunction. Future studies with longer follow-up could clarify the implications of subtle thyroid alterations in cognition.

Episodic Memory and Verbal Fluency Tasks: Normative Data from Nine Nationally Representative Samples

OBJECTIVE

This study aims to generate country-specific norms for two episodic memory tasks and a verbal fluency test among middle-aged and older adults using nationally representative data from nine low-, middle-, and high-income countries.

METHOD

Data from nine countries in Africa, Asia, Europe, and Latin America were analyzed (n = 42,116; aged 50 years or older). Episodic memory was assessed with the word list memory (three trials of immediate recall) and word list recall (delayed recall). Verbal fluency was measured through the animal naming task. Multiple linear regression models with country-specific adjustments for gender, age, education, and residential area were carried out.

RESULTS

Both age and education showed high influence on test performance (i.e. lower cognitive performance with increasing age and decreasing years of education, respectively), while the effect of sex and residential area on cognitive function was neither homogeneous across countries nor across cognitive tasks.

CONCLUSIONS

Our study provided sex-, age-, education-, and residential area-specific regression-based norms that were obtained from one of the largest normative study worldwide on verbal recall and fluency tests to date. Findings derived from this study will be especially useful for clinicians and researchers based at countries where cognitive norms are limited.

NeuroBel: Spanish screening test for oral psycholinguistics disabilities in elderly people with mild cognitive impairment and early-stage Alzheimer's disease

INTRODUCTION

The NeuroBel is a short test that allows for psycholinguistic assessment of basic processes of oral comprehension and language production deterioration in the elderly. The objective is to carry out a pilot study of the initial reference values and cut-off points of this battery using a sample of Spanish elderly adults, with and without cognitive impairment, and detecting performance differences among them.

METHOD

NeuroBel consists of 8 tasks that analyze oral language functioning from the theoretical model proposed by the Psycholinguistic approach. Seventy-five Spanish monolingual adult-elderly participants of both genders. Of those, 25 with Alzheimer's disease (AD) in the initial phase, 25 with mild cognitive impairment (MCI) and 25 participants without cognitive impairment (Controls). All subjects were evaluated using NeuroBel.

RESULTS

There are significant differences between the three groups. The participants with AD are significantly worse in the total score of NeuroBel. A discriminant analysis shows that 86.7% of the cases appear correctly classified in the groups originally selected. Likewise, participants with MCI obtained results that are statistically significantly worse than the control group. NeuroBel shows a high correlation with the MMSE (.89) and Sensitivity (.96) in the determination of AD and cognitive deterioration (AD + MCI vs. Controls). The area under the ROC curve is .97 in the contrast of AD vs. Controls and .98 in the determination of cognitive deterioration (AD + MCI vs. Controls). The canonical discriminant functions and the precision cut-offs from the ROC analyses are also shown in the results.

CONCLUSIONS

NeuroBel is shown as a "very good" test in the detection of cognitive-linguistic impairment in elderly-adults.

Letter and Category Fluency Performance Correlates with Distinct Patterns of Cortical Thickness in Older Adults

Verbal fluency tasks are generally thought to be mediated by frontal brain regions for letter fluency and temporal regions for category fluency. This idea, however, is primarily based on lesion studies and adapted versions of the fluency tasks in functional neuroimaging, without fundamental evidence from structural neuroimaging in healthy individuals. We investigated the cortical structural correlates of letter and category fluency, including overlapping and different regions, in 505 individuals who participated in a community-based study of healthy aging. The correlation between cortical thickness and verbal fluency in whole-brain analyses revealed distinct cortical signatures for letter fluency, primarily in frontal regions, and category fluency, in frontal and temporal-parietal regions. There was a dissociation in the left inferior frontal gyrus between letter and category fluency, with increased thickness in the posterior-dorsal versus anterior-ventral parts, respectively. These results distinguish the detailed anatomical correlates for verbal fluency within the coarse frontal-temporal distinction inferred from lesion studies and among the mixture of regions identified in functional neuroimaging. The evidence for the anatomical substrates of letter and category fluency, each recruiting slightly different language and cognitive processes, can serve both clinical applications as well as a deeper theoretical understanding of the organization of the cerebral cortex.

Association of Sarcopenia With Performance on Multiple Cognitive Domains: Results From the ELSA-Brasil Study

Background

Sarcopenia and cognitive impairment share pathophysiological paths and risk factors. Our aim was to investigate the association of sarcopenia and its defining components with cognitive performance in middle-aged and older adults.

Methods

This cross-sectional analysis included 5,038 participants from the ELSA-Brasil Study, aged ≥ 55 years. Muscle mass was evaluated by bioelectrical impedance analysis and muscle strength by handgrip strength. Sarcopenia was defined according to the Foundation for the National Institutes of Health. Cognition was evaluated using delayed word recall test, semantic verbal fluency test, and trail making test version B. Possible confounders included sociodemographic characteristics, lifestyle, and clinical comorbidities.

Results

The frequencies of sarcopenia, low muscle mass, and low muscle strength were 1.8%, 23.3%, and 4.4%, respectively. After adjustment for possible confounders, poorer performance on the verbal fluency test was associated with sarcopenia (β = −0.20, 95% confidence interval [CI] = −0.38; −0.01, p = .03) and low muscle mass (β = −0.08, 95% CI = −0.14; −0.01, p = .02). Low muscle strength was associated with poorer performance in the delayed word recall test (β = −0.14, 95% CI = −0.27; −0.02, p = .02), verbal fluency test (β = −0.14, 95% CI = −0.26; −0.02, p = .03), and trail making test (β = −0.15, 95% CI = −0.27; −0.03, p = .01).

Conclusions

Sarcopenia was associated with poorer performance on the verbal fluency test, and low muscle strength was associated with poorer performance in all cognitive tests in middle-aged and older adults.

Executive and Language Subjective Cognitive Decline Complaints Discriminate Preclinical Alzheimer's Disease from Normal Aging

BACKGROUND

There is a need to specify the profile of subjective cognitive decline in preclinical Alzheimer's disease (preAD).

OBJECTIVES

To explore specific items of the Subjective Cognitive Decline Questionnaire (SCD-Q) that discriminate preAD from normal aging.

METHODS

68 cognitively normal older adults were classified as controls (n = 52) or preAD (n = 16) according to amyloid-β (Aβ) levels. An exploratory factor analysis and item analysis of the SCD-Q were performed. Informant reports of the SCD-Q were used to corroborate the findings of self-reports. One-year neuropsychological follow-up was available.

RESULTS

Four SCD-Q factors were extracted: EM-factor (episodic memory), A-factor (attention), O-factor (organization), and L-factor (language). PreAD reported a significantly higher decline in L-factor (F(1) = 6.49; p = 0.014) and A-factor (F(1) = 4.04; p = 0.049) compared to controls, and showed a higher frequency of perceived decline in SCD-Q items related with language and executive tasks (Sig-items.) Significant discriminative powers for Aβ-positivity were found for L-factor (AUC = 0.75; p = 0.003) and A-factor (AUC = 0.74; p = 0.004). Informants in the preAD group confirmed significantly higher scores in L-factor and Sig-items. A significant time×group interaction was found in the Semantic Fluency and Stroop tests, with the preAD group showing a decrease in performance at one-year.

CONCLUSIONS

Our results suggest that SCD-Q items related with language and executive decline may help in prediction algorithms to detect preAD. Validation in an independent population is needed.

Patterns of cognitive deficits in persons with spinal cord injury as compared with both age-matched and older individuals without spinal cord injury

Context/Objective: Cognitive deficits can impact as many as 60% of individuals with spinal cord injury (SCI). In an effort to identify the nature of cognitive deficits in SCI, we examined neuropsychological test performance in individuals with SCI, age matched healthy controls and older healthy controls.Design: Participants completed a motor-free neuropsychological test battery assessing attention, working memory, information processing speed, new learning /memory and executive control.Setting: Outpatient rehabilitation research facility.Participants: Participants included 60 individuals with chronic spinal cord injury [SCI; 32 with paraplegia (T2-T12) and 28 with tetraplegia (C3-T1)], 30 age-matched healthy controls (AMHC; 30-40 years old) and 20 older healthy controls (OHC; 50-60 years old).Outcome Measures: Wechsler Intelligence Scale - 3^rd edition (WAIS-III) Digit Span and Letter-Number Sequencing; Symbol Digit Modalities Test (SDMT) - oral version; California Verbal Learning Test-II; Paced Auditory Serial Addition Test (PASAT); Wechsler Abbreviated Scale of Intelligence (WASI); Delis-Kaplan Executive Function System; Verbal Fluency subtest.Results: Significant differences were noted between the SCI and AMHC groups on measures of information processing speed, new learning and memory, and verbal fluency. No significant differences were noted between the groups on tests of attention or working memory.Conclusion: The current study documented differences in specific realms of cognitive functioning between a chronic SCI sample and AMHC. Implications for cognitive rehabilitation and overall quality of life are discussed. Additional research is needed utilizing a more comprehensive battery of motor-free neuropsychological tests that avoid the confound of upper limb motor limitations on cognitive performance.

Quanti-qualitative components of the semantic verbal fluency test in cognitively healthy controls, mild cognitive impairment, and dementia subtypes

This study is aimed to evaluating the underlying cognitive strategies used during Semantic Verbal Fluency (SVF) performance and comparing the differences between cognitively healthy controls (CHC), amnestic and amnestic-multiple domain mild cognitive impairment (a-MCI and a-md-MCI), Alzheimer's disease (AD), Lewy body dementia (LBD), and behavioral variant frontotemporal dementia (bvFTD). The cross-sectional study comprised 236 participants involving 78 CHC individuals, 33 a-MCI and 48 a-md-MCI, 39 AD, 22 LBD, and 16 bvFTD patients. Scores differed significantly when comparing CHC with dementia groups, showing medium to large variances. The best components in distinguishing between CHC and the dementia groups were the SVF-Total score and SVF-Cluster Size variables. CHC showed different performance in the SVF-Cluster Size variable compared with a-md-MCI, AD, and bvFTD; whereas, in the SVF-Mean Cluster Size, CHC differed from MCI's, AD, and LBD. The switching component displayed smaller capacity to differentiate between the clinical groups. The effect size was large comparing AD with bvFTD (1.267) and medium comparing AD with LBD (0.689) using the SVF-Cluster Size variable, but small using the other variables for the comparisons between dementia groups. Quanti-qualitative examination of the SVF may provide a valuable clue in distinguishing CHC from MCI and different dementia subtypes.

Inhibitory Control, Task/Rule Switching, and Cognitive Planning in Vascular Dementia: Are There Any Differences From Vascular Aging?

Recent studies have shown that patients diagnosed with Vascular Dementia (VaD) exhibit deficits in executive functions. According to “vascular hypothesis of cognitive aging,” community-dwelling older adults having risk factors for vascular disease development (RVD) may suffer from cognitive decline of the same type. The aim of the study was to assess the level of specific executive functions (EF) that have been revealed as most affected by vascular abnormalities, in older adults with incipient VaD and RVD. Subsequently specific ways of EF measuring could be suggested for more accurate diagnosis of early stage VaD. The study compared three adult groups (N = 60): (a) patients diagnosed with incipient VaD, according to DSM-5 criteria (n = 20); (b) community-dwelling older adults presenting cardiovascular risk factors (RVD; n = 20); (c) healthy young adult controls (n = 20). Three types of executive functions were examined: inhibitory control, cognitive flexibility as rule/task switching, and planning. The following D-KEFS subtests were administered for their evaluation: The ‘Color-Word Interference Test,’ the ‘Verbal Fluency Test,’ and the ‘Tower Test.’ Mixed-measures ANOVA, MANOVA, and one-way ANOVA as well as Scheffe post hoc test were applied to the data of the scores in each condition of each test. The results showed that VaD patients had significantly lower performance in test conditions requiring switching and planning, compared to RVD group and young controls. The specific deficits of VaD patients, compared to older adults presenting RVD according to multiple-group path analyses were: more uncorrected errors in inhibition, the use of semantic knowledge primarily instead of switching ability to switch between semantic categories, as well as a lower level of movement precision in planning.

Working Memory Deficits After Lesions Involving the Supplementary Motor Area

The Supplementary Motor Area (SMA)—located in the superior and medial aspects of the superior frontal gyrus—is a preferential site of certain brain tumors and arteriovenous malformations, which often provoke the so-called SMA syndrome. The bulk of the literature studying this syndrome has focused on two of its most apparent symptoms: contralateral motor and speech deficits. Surprisingly, little attention has been given to working memory (WM) even though neuroimaging studies have implicated the SMA in this cognitive process. Given its relevance for higher-order functions, our main goal was to examine whether WM is compromised in SMA lesions. We also asked whether WM deficits might be reducible to processing speed (PS) difficulties. Given the connectivity of the SMA with prefrontal regions related to executive control (EC), as a secondary goal we examined whether SMA lesions also hampered EC. To this end, we tested 12 patients with lesions involving the left (i.e., the dominant) SMA. We also tested 12 healthy controls matched with patients for socio-demographic variables. To ensure that the results of this study can be easily transferred and implemented in clinical practice, we used widely-known clinical neuropsychological tests: WM and PS were measured with their respective Wechsler Adult Intelligence Scale indexes, and EC was tested with phonemic and semantic verbal fluency tasks. Non-parametric statistical methods revealed that patients showed deficits in the executive component of WM: they were able to sustain information temporarily but not to mentally manipulate this information. Such WM deficits were not subject to patients' marginal PS impairment. Patients also showed reduced phonemic fluency, which disappeared after controlling for the influence of WM. This observation suggests that SMA damage does not seem to affect cognitive processes engaged by verbal fluency other than WM. In conclusion, WM impairment needs to be considered as part of the SMA syndrome. These findings represent the first evidence about the cognitive consequences (other than language) of damage to the SMA. Further research is needed to establish a more specific profile of WM impairment in SMA patients and determine the consequences of SMA damage for other cognitive functions.

Thyrotropin level and cognitive performance: Baseline results from the ELSA-Brasil Study

BACKGROUND AND AIMS

The role of subtle thyroid alterations, such as subclinical thyroid disease and low/high serum thyrotropin (TSH) within the normal range, on cognitive decline is controversial. The aim of this study was to evaluate the association of serum TSH and subclinical thyroid dysfunction with performance on cognitive tests in a large sample of Brazilian middle-aged adults without overt thyroid disease.

METHODS

In this cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health, we excluded individuals aged 65 years and older, with overt thyroid dysfunction, prevalent stroke, in use of medications that affect thyroid function or that indicate neurologic diseases, and from Asian or indigenous ethnicity. Thyroid status was assessed by serum TSH and free thyroxine (only when the TSH was altered). Individuals were divided according to TSH tertiles and classified according to thyroid function as euthyroidism, subclinical hypothyroidism, or subclinical hyperthyroidism. Cognition was evaluated using delayed word recall test, semantic verbal fluency test, and trail making test version B. The associations of cognitive tests performance with TSH tertiles (using the middle tertile as reference) and thyroid function were investigated using linear regression models, adjusted for an extensive set of possible confounders (sociodemographic characteristics, cardiovascular risk factors, and depression).

RESULTS

The mean age of the 10,362 participants was 49.5±7.4years, 52.3% women. After adjustment for confounders, the first TSH tertile was associate with worse performance on the trail making test (β=-0.05, 95% CI=-0.09; -0.01, p=0.017). When restricting the analysis to the 9769 individuals with TSH within the normal range, the association between TSH and performance on the trail making test remained significant (β=-0.05, 95% CI=-0.09; -0.01, p=0.020) on multiple linear regression. Subclinical thyroid disease was not associated with performance on cognitive tests.

CONCLUSION

Low TSH is associated with poorer performance on an executive function test in middle-aged adults without overt thyroid dysfunction.

Coronary artery calcification and cognitive function: cross-sectional results from the ELSA-Brasil study

OBJECTIVES

We examined the relationship between coronary artery calcification (CAC) score and performance in cognitive tests in a large Brazilian sample.

METHODS

In this cross-sectional study, 4104 participants (mean age = 50.9 ± 8.8 years old, 54% female) from the Brazilian Longitudinal Study of Adult Health had complete information for CAC and cognitive tests. We used linear regression models adjusted for sociodemographics, cardiovascular risk factors (hypertension, diabetes, smoking, alcohol use, physical activity, and body mass index), depression, and thyroid function. To investigate potential different associations for middle-aged and older adults, we stratified the analysis by age groups.

RESULTS

Participants with CAC ≥ 100 Agatston score had poorer performance in the trail making test compared to those with CAC < 100 Agatston score (β = -0.101, 95% CI = -0.194; -0.010, p = 0.03). We did not find any other association between CAC and cognitive tests. When we investigated the effect modification between CAC and age on cognitive tests, only the effect modification on global cognition (p = 0.02) and trail making test was significant (p = 0.0003).

CONCLUSIONS

Higher CAC was weakly associated with poorer performance in an executive function test in a large sample from the Brazilian Longitudinal Study of Adult Health. Copyright © 2017 John Wiley & Sons, Ltd.

Migraine and cognitive function: Baseline findings from the Brazilian Longitudinal Study of Adult Health: ELSA-Brasil

Background The association between migraine and cognitive performance is unclear. We analyzed whether migraine is associated with cognitive performance among participants of the Brazilian Longitudinal Study of Adult Health, ELSA-Brasil. Methods Cross-sectional analysis, including participants with complete information about migraine and aura at baseline. Headache status (no headaches, non-migraine headaches, migraine without aura and migraine with aura), based on the International Headache Society classification, was used as the dependent variable in the multilinear regression models, using the category "no headache" as reference. Cognitive performance was measured with the Consortium to Establish a Registry for Alzheimer's Disease word list memory test (CERAD-WLMT), the semantic fluency test (SFT), and the Trail Making Test version B (TMTB). Z-scores for each cognitive test and a composite global score were created and analyzed as dependent variables. Multivariate models were adjusted for age, gender, education, race, coronary heart disease, heart failure, hypertension, diabetes, dyslipidemia, body mass index, smoking, alcohol use, physical activity, depression, and anxiety. In women, the models were further adjusted for hormone replacement therapy. Results We analyzed 4208 participants. Of these, 19% presented migraine without aura and 10.3% presented migraine with aura. All migraine headaches were associated with poor cognitive performance (linear coefficient β; 95% CI) at TMTB -0.083 (-0.160; -0.008) and poorer global z-score -0.077 (-0.152; -0.002). Also, migraine without aura was associated with poor cognitive performance at TMTB -0.084 (-0.160, -0.008 and global z-score -0.077 (-0.152; -0.002). Conclusion In participants of the ELSA-study, all migraine headaches and migraine without aura were significantly and independently associated with poorer cognitive performance.

Serum uric acid is associated with better executive function in men but not in women: Baseline assessment of the ELSA-Brasil study

BACKGROUND

Serum uric acid (SUA) may protect against free radical stress damage and was previously linked to cognitive impairment in older adults, but evidence in middle-aged adults is scarce.

PURPOSE

We sought to analyze whether SUA is associated with cognitive performance in apparently healthy middle-aged participants in the ELSA-Brasil cohort study.

METHODS

We excluded participants older than age 65, those taking allopurinol, benzbromarone, or medications that could impair cognitive performance, those with previous stroke, and those with incomplete data on cognitive tests or SUA. The Consortium to Establish a Registry for Alzheimer's Disease Word List Memory Test (CERAD-WLMT), the Semantic Fluency Test (SFT), and the Trail Making Test version B (TMT) were used as dependent variables. Sex-specific linear regression models were used to assess the association between SUA and cognitive tests, adjusted by age, education, hypertension, dyslipidemia, diabetes, smoking, alcohol consumption, body mass index, coronary heart disease, renal function, depression, aspirin use, thyroid function, and menopausal status (in women). We used the Bonferroni procedure to control for the false discovery rate associated with multiple comparisons.

RESULTS

We analyzed cross-sectional data from 6751 women and 5464 men. Mean age and standard deviation (SD) of the sample was 49.6 (SD 7.4) years for men and 49.9 (SD 7.3) years for women. The majority of men (52%) and women (51%) were white. Mean SUA value was 4.75 (SD 1.16) mg/dL in women and 6.44 (SD 1.39) mg/dL in men. Multivariate linear models showed no association in women and a significant inverse association between SUA levels and TMT (β=-3.106, 95% CI=-4.594; -1.618, p=0.0004) in men.

CONCLUSION

In a middle-aged subset population, SUA is associated with better performance on an executive function test in men, but not in women in the ELSA-Brasil cohort study.

The Alzheimer's Prevention Clinic at Weill Cornell Medical College / New York - Presbyterian Hospital: Risk Stratification and Personalized Early Intervention

In July 2013, Weill Cornell Medical College founded the first Alzheimer's Prevention Clinic (APC) in the United States, providing direct clinical care to family members of patients with Alzheimer's disease (AD) as part of the Weill Cornell Memory Disorders Program. At the APC, patients seeking to lower their AD risk undergo a comprehensive assessment, receive a personalized plan based on rapidly evolving scientific evidence, and are followed over time using validated as well as emerging clinical and research technologies. The APC approach applies the principles of pharmacogenomics, nutrigenomics and clinical precision medicine, to tailor individualized therapies for patients. Longitudinal measures currently assessed in the clinic include anthropometrics, cognition, blood biomarkers (i.e., lipid, inflammatory, metabolic, nutritional) and genetics, as well as validated, self-reported measures that enable patients to track several aspects of health-related quality of life. Patients are educated on the fundamental concepts of AD prevention via an interactive online course hosted on Alzheimer's Universe (www.AlzU.org), which also contains several activities including validated computer-based cognitive testing. The primary goal of the APC is to employ preventative measures that lower modifiable AD risk, possibly leading to a delay in onset of future symptoms. Our secondary goal is to establish a cohort of at-risk individuals who will be primed to participate in future AD prevention trials as disease-modifying agents emerge for testing at earlier stages of the AD process. The clinical services are intended to lower concern for future disease by giving patients a greater sense of control over their brain health.

What do verbal fluency tasks measure? Predictors of verbal fluency performance in older adults

This study examined the contributions of verbal ability and executive control to verbal fluency performance in older adults (n = 82). Verbal fluency was assessed in letter and category fluency tasks, and performance on these tasks was related to indicators of vocabulary size, lexical access speed, updating, and inhibition ability. In regression analyses the number of words produced in both fluency tasks was predicted by updating ability, and the speed of the first response was predicted by vocabulary size and, for category fluency only, lexical access speed. These results highlight the hybrid character of both fluency tasks, which may limit their usefulness for research and clinical purposes.

Verbal fluency in cerebral small vessel disease and Alzheimer's disease

Patterns of verbal fluency deficits have been explored across different neurodegenerative disorders. This study sought to investigate the specific pattern of verbal fluency performance in cerebral small vessel disease (SVD), which is the most common cause of vascular cognitive impairment, and compare this with Alzheimer's disease (AD). Participants with SVD (n = 45), AD (n = 24) and healthy controls (n = 80) completed assessments of semantic and phonemic fluency. Mixed-model analyses of covariance were used to compare performance on the different fluency tasks between the groups, and a discriminant function analysis was conducted to examine group differentiation. The SVD group was impaired in both fluency tasks when compared to the controls. In contrast, the AD group displayed impairment in semantic fluency only. Discriminant function analysis revealed that fluency scores correctly classified 80% of SVD patients and 92% of AD patients. The pattern of performance observed in the SVD group may reflect deficits in executive function and processing speed impacting equivalently on semantic and phonemic fluency. The differences between the SVD and AD groups highlighted in this study may be useful for distinguishing between these conditions.

Clinical and psychological characteristics of the initial cohort of the Dominantly Inherited Alzheimer Network (DIAN)

OBJECTIVE

The purpose was to describe clinical, cognitive, and personality characteristics at baseline assessment of 249 participants, 19 to 60 years of age, in a multinational longitudinal study of autosomal dominant Alzheimer's disease (ADAD).

METHOD

Participants (74% cognitively normal) were from ADAD families with mutations in 1 of 3 genes (APP, PSEN1, or PSEN2). Mixed model analyses, including family as a random variable and controlling for years from expected time of symptomatic onset of ADAD based on parental age at onset, compared 3 groups (cognitively normal mutation noncarriers, cognitively normal mutation carriers, very mildly impaired mutation carriers).

RESULTS

Global cognitive deficits similar to those observed in late-life sporadic Alzheimer's disease (AD) existed in very mild ADAD compared with cognitively normal carriers and noncarriers on all but 2 measures (Digit Span Backward, Letter Fluency for FAS) of episodic memory, semantic memory, working memory, attention, and speeded visuospatial abilities. Demented individuals were less extraverted, open, and conscientious than cognitively normal participants on the International Personality Item Pool. Differences in the relation between 3 measures (Logical Memory, Digit Symbol, attention switching) and time to expected age at symptomatic onset indicate that cognitive deficits on some measures can be detected in mutation carriers prior to symptomatic AD, and hence should be useful markers in subsequent longitudinal follow-up.

CONCLUSIONS

Overall cognitive and personality deficits in very mild ADAD are similar to those seen in sporadic AD. Cognitive deficits also occur in asymptomatic mutation carriers who are closer to the expected time of dementia onset.

Analysis of verbal fluency ability in amnestic and non-amnestic mild cognitive impairment

The purpose of this study was to investigate the pattern of performance on letter and category fluency tests of individuals with mild cognitive impairment (MCI). Previous research has suggested that organization strategies, including "clustering" (i.e., groups of related words) and "switching" (i.e., shift from one cluster to another), are important for efficient verbal fluency performance. Participants were 25 individuals with single-domain amnestic MCI (aMCI), 49 with multidomain aMCI, 16 with non-amnestic MCI (naMCI), and 90 cognitively healthy older adults. Fluency performances were analyzed across two 30-s intervals for total words produced, cluster size, and switching. Analyses of variance (ANOVAs) with follow-up tests revealed that the single-domain aMCI group performed comparably with healthy controls on each dependent measure across both fluency tasks. In contrast, the multidomain aMCI group showed performance decrements in total words and switching production compared with healthy controls on both fluency tasks, whereas the naMCI group produced fewer words and switches on letter fluency. Each group generated more words and switches during the first 30-s on both fluency tasks, with the exception of the naMCI group, whose switching on letter fluency did not decrease as the task progressed. As indicated by the single-domain aMCI group's unimpaired performance, our findings demonstrate that verbal fluency performance decreases as domains beyond memory become impaired in MCI. Reduced switching ability, which has been linked to prefrontal executive functioning, contributed the most to the poorer performance of individuals with multidomain MCI and naMCI.

Clustering and switching during a semantic verbal fluency test contribute to differential diagnosis of cognitive impairment

The verbal fluency test (VFT) can be dissociated into "clustering" (generating words within subcategories) and "switching" (shifting between clusters), which may be valuable in differential diagnosis. In the current study, we investigated the validity of VFT in the differential diagnosis of Alzheimer's disease (AD, n = 65), vascular dementia (VaD, n = 65), mild cognitive impairment (MCI, n = 92), and vascular cognitive impairment without dementia (VCIND, n = 76) relative to cognitively normal senior controls (NC, n = 374). We found that in the NC group, the total correct score was significantly correlated with age and education; males generated more subcategories; cluster size increased with education, and subcategory and switching decreased with age. A significantly progressive advantage was observed in VFT scores in the sequence NC > MCI/VCIND > AD/VaD, and this significantly discriminated dementia patients from the other groups. AD patients performed better in all four VFT scores than VaD patients. Subcategory and switching scores significantly distinguished AD from VaD patients (AD > VaD; mean difference, 0.50 for subcategory, P <0.05; 0.71 for switching, P <0.05). MCI patients scored higher than VCIND patients, but the difference did not reach statistical significance. These results suggest that semantic VFT is useful for the detection of MCI and VCIND, and in the differential diagnosis of cognitive impairment.

Alogia and formal thought disorder: differential patterns of verbal fluency task performance

BACKGROUND

There is evidence that alogia and formal thought disorder (FTD), two prominent speech symptoms in schizophrenia, are associated with different patterns of verbal fluency task deficits. Verbal fluency is thought to involve several cognitive mechanisms, including controlled retrieval, semantic memory, and context processing.

METHODS

The current research examined whether alogia and FTD were associated with different patterns of verbal fluency performance and whether these patterns of verbal fluency performance would implicate deficits in controlled retrieval, semantic memory, or context processing. In the current research, 34 people with schizophrenia completed letter and category fluency tasks and detailed ratings of alogia and FTD symptoms were made from typed transcripts.

RESULTS

Overall, alogia was associated with increased response latency between each word on the category fluency task, suggesting an association between alogia and poor controlled retrieval. In contrast, FTD was associated with a decreased proportion of semantically-related words on letter fluency, suggesting an association between FTD and poor context processing.

CONCLUSIONS

Alogia and FTD appear to be associated with unique patterns of fluency performance, implicating separate cognitive mechanisms.

Semantic clustering as a neuropsychological predictor for amnestic-MCI

Recent research has demonstrated that patients with Alzheimer's disease (AD) show deficits in semantic processing when compared to cognitively healthy individuals. This difference is thought to be attributed to losses in higher cortical systems that are predominantly associated with executive functioning. The first aim of the study will be to determine if differences in semantic clustering can accurately differentiate patients with amnestic mild cognitive impairment (aMCI) from cognitively normal (CN) individuals. The second aim will be to determine the extent to which semantic processing might be associated with executive functions. Data from 202 (134 CN, 68 aMCI) participants were analyzed to quantify differences in semantic clustering ratios on the HVLT-R. Study participants ages ranged from 51 to 87 with education ranging from 6 to 20 years. ANCOVA revealed statistically significant differences on semantic clustering ratios (p < .001). Moderate correlations between semantic clustering Category Fluency Test (r = .45) were also found. Statistically significant group differences were also present on Trails-B and WAIS-R Digit Symbol performance (p < .001). Overall, these data indicate that deficits in semantic clustering are present in aMCI patients.

Onset and rate of cognitive change before dementia diagnosis: findings from two Swedish population-based longitudinal studies

We used data from two population-based longitudinal studies to estimate time of onset and rate of accelerated decline across cognitive domains before dementia diagnosis. The H70 includes an age-homogeneous sample (127 cases and 255 non-cases) initially assessed at age 70 with 12 follow-ups over 30 years. The Kungsholmen Project (KP) includes an age-heterogeneous sample (279 cases and 562 non-cases), with an average age of 82 years at initial assessment, and 4 follow-ups spanning 13 years. We fit mixed linear models to the data and determined placement of change points by a profile likelihood method. Results demonstrated onset of accelerated decline for fluid (speed, memory) versus crystallized (verbal, clock reading) abilities occurring approximately 10 and 5 years before diagnosis, respectively. Although decline before change points was greater for fluid abilities, acceleration was more pronounced for crystallized abilities after the change points. This suggests that onset and rate of acceleration vary systematically along the fluid-crystallized ability continuum. There is early onset in fluid abilities, but these changes are difficult to detect due to substantial age-related decline. Onset occurred later and acceleration was greater in crystallized abilities, suggesting that those markers may provide more valid identification of cases in later stages of the prodromal phase.

Cognition, language, and clinical pathological features of non-Alzheimer's dementias: an overview

There are many distinct forms of dementia whose pharmacological and behavioral management differ. Differential diagnosis among the dementia variants currently relies upon a weighted combination of genetic and protein biomarkers, neuroanatomical integrity, and behavior. Diagnostic specificity is complicated by a high degree of overlap in the initial presenting symptoms across dementia subtypes. For this reason, reliable markers are of considerable diagnostic value. Communication disorders have proven to be among the strongest predictors for discriminating among dementia subtypes. As such, speech-language pathologists may be poised to make an increasingly visible contribution to dementia diagnosis and its ongoing management. The value and durability of this potential contribution, however, demands an improved discipline-wide knowledge base about the unique features associated with different dementia variants. To this end we provide an overview of cognition, language, and clinical pathological features of four of the most common non-Alzheimer's dementias: frontotemporal dementia, vascular dementia, Lewy body disease dementia, and Parkinson's disease dementia.

LEARNING OUTCOMES

Readers will learn characteristics and distinguishing features of several non-Alzheimer's dementias, including Parkinson's disease dementia, frontotemporal dementia, vascular dementia, and Lewy body dementia. Readers will also learn to distinguish between several variants of frontotemporal dementia. Finally, readers will gain knowledge of the term primary progressive aphasia as it relates to the aforementioned dementia etiologies.

Category verbal fluency predicted changes in behavioral and psychological symptoms of dementia in patients with Alzheimer's disease

AIM

Alzheimer's disease (AD) is characterized by cognitive symptoms and behavioral symptoms, and their association is inconsistent. The aim of this study was to investigate the relationship between cognitive function and the changes in behavioral and psychological symptoms of dementia (BPSD) in patients with AD.

METHODS

A total of 101 patients with probable AD were enrolled (57 women and 44 men, mean age 77.6 +/- 7.7 years). The Category Verbal Fluency Test (CVFT), the Mini-Mental State Examination (MMSE), the Constructional Praxis Test, the Delayed Word Recall Test, the Clinical Dementia Rating Scale, and the Neuropsychiatry Inventory (NPI) were administered at baseline. The NPI was reassessed with a median follow-up duration of 10 months (range 6-18 months). The change in the NPI scores was defined as the end-point score of the NPI minus the initial one. The associations between the changes in NPI total score, its four subdomains (hyperactivity, psychosis, affection, and apathy), and cognitive function were examined using multivariate linear models. The results were adjusted for confounders including demographics, baseline NPI, and duration of follow up.

RESULTS

The mean MMSE was 18.6 +/- 5.6, the CVFT score was 7.1 +/- 3.9, and the NPI score was 10.9 +/- 13.8. Regression analyses found that the CVFT score (beta = -0.32, P = 0.004) was significantly associated with the change in NPI score, but not the MMSE, the Delayed Word Recall score, or the Constructional Praxis score. The CVFT score was significantly associated with changes in the psychosis subdomain (beta = -0.34, P = 0.001), but not the other subdomains.

CONCLUSIONS

Our study showed that CVFT was predictive of the changes in behavior disturbance in patients with AD, particularly in the psychosis domain.

Limitations in differentiating vascular dementia from Alzheimer's disease with brief cognitive tests

OBJECTIVE: To investigate the diagnostic value of brief cognitive tests in differentiating vascular dementia (VaD) from Alzheimer's disease (AD). METHOD: Fifteen patients with mild VaD, 15 patients with mild probable AD and 30 healthy controls, matched for age, education and dementia severity, were submitted to the following cognitive tests: clock drawing (free drawing and copy), category and letter fluency, delayed recall test of figures and the EXIT 25 battery. RESULTS: VaD patients performed worse than AD patients in category fluency (p=0.014), letter fluency (p=0.043) and CLOX 2 (p=0.023), while AD cases performed worse than VaD patients in delayed recall (p=0.013). However, ROC curves for these tests displayed low sensitivity and specificity for the differential diagnosis between VaD and AD. CONCLUSION: Although the performance of VaD and AD patients was significantly different in some cognitive tests, the value of such instruments in differentiating VaD from AD proved to be very limited.

Verbal fluency in the detection of mild cognitive impairment and Alzheimer's disease among Brazilian Portuguese speakers: the influence of education

BACKGROUND

Verbal fluency (VF) tasks are simple and efficient clinical tools to detect executive dysfunction and lexico-semantic impairment. VF tasks are widely used in patients with suspected dementia, but their accuracy for detection of mild cognitive impairment (MCI) is still under investigation. Schooling in particular may influence the subject's performance. The aim of this study was to compare the accuracy of two semantic categories (animals and fruits) in discriminating controls, MCI patients and Alzheimer's disease (AD) patients.

METHODS

178 subjects, comprising 70 controls (CG), 70 MCI patients and 38 AD patients, were tested on two semantic VF tasks. The sample was divided into two schooling groups: those with 4-8 years of education, and those with 9 or more years.

RESULTS

Both VF tasks - animal fluency (VFa) and fruits fluency (VFf) - adequately discriminated CG from AD in the total sample (AUC = 0.88 +/- 0.03, p < 0.0001) and in both education groups, and high educated MCI from AD (VFa: AUC = 0.82 +/- 0.05, p < 0.0001; VFf: AUC = 0.85 +/- 0.05, p < 0.0001). Both tasks were moderately accurate in discriminating CG from MCI (VFa: AUC = 0.68 +/- 0.04, p < 0.0001; VFf: AUC = 0.73 +/- 0.04, p < 0.0001) regardless of the schooling level, and MCI from AD in the total sample (VFa: AUC = 0.74 +/- 0.05, p < 0.0001; VFf: AUC = 0.76 +/- 0.05, p < 0.0001). Neither of the two tasks differentiated low educated MCI from AD. In the total sample, fruits fluency best discriminated CG from MCI and MCI from AD; a combination of the two improved the discrimination between CG and AD.

CONCLUSIONS

Both categories were similar in discriminating CG from AD; the combination of both categories improved the accuracy for this distinction. Both tasks were less accurate in discriminating CG from MCI, and MCI from AD.

Impaired category fluency in medial temporal lobe amnesia: the role of episodic memory

Memory tasks are often classified as semantic or episodic, but recent research shows that these types of memory are highly interactive. Category fluency, for example, is generally considered to reflect retrieval from semantic memory, but behavioral evidence suggests that episodic memory is also involved: participants frequently draw on autobiographical experiences while generating exemplars of certain categories. Neuroimaging studies accordingly have reported increased medial temporal lobe (MTL) activation during exemplar generation. Studies of fluency in MTL amnesics have yielded mixed results but were not designed to determine the precise contributions of episodic memory. We addressed this issue by asking MTL amnesics and controls to generate exemplars of three types of categories. One type tended to elicit autobiographical and spatial retrieval strategies (AS). Another type elicited strategies that were autobiographical but nonspatial (AN). The third type elicited neither autobiographical nor spatial strategies (N). Amnesic patients and control participants generated exemplars for eight categories of each type. Patients were impaired on all category types but were more impaired on AS and AN categories. After covarying for phonemic fluency (total FAS score), the N category impairment was not significant, but the impairment on AS and AN categories remained. The same results were obtained for patients with lesions restricted to the MTL and those with more extensive lesions. We conclude that patients' episodic memory impairment hindered their performance on this putatively semantic task. This interaction between episodic and semantic memory might partially account for fluency deficits seen in aging, mild cognitive impairment, and Alzheimer's disease.

Lexical and semantic fluency discrepancy scores in aMCI and early Alzheimer's disease

Episodic memory is compromised in amnestic mild cognitive impairment (aMCI), but lesser deficits in other cognitive domains are also commonly observed and may be helpful in identifying this group. The relative difference in performance on lexical and semantic fluency tasks may be a sensitive and specific measure in aMCI and early Alzheimer's disease (AD). We compared four groups of participants, 35 early AD, 47 aMCI, 24 healthy controls, and 18 depressive out-patient controls, on semantic and lexical fluency as well as other neuropsychological tests. Early AD and aMCI patients showed a distinct pattern of semantic impairment in the two fluency measures compared with the healthy and depressive controls. The findings implicate early failure of the semantic memory system in aMCI and AD and suggest that consideration of the discrepancy in performance on semantic and lexical fluency measures may help in the early identification of AD.

Plaque and tangle imaging and cognition in normal aging and Alzheimer's disease

Amyloid plaques and tau neurofibrillary tangles, the pathological hallmarks of Alzheimer's disease (AD), begin accumulating in the healthy human brain decades before clinical dementia symptoms can be detected. There is great interest in how this pathology spreads in the living brain and its association with cognitive deterioration. Using MRI-derived cortical surface models and four-dimensional animation techniques, we related cognitive ability to positron emission tomography (PET) signal from 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile ([(18)F]FDDNP), a molecular imaging probe for plaques and tangles. We examined this relationship at each cortical surface point in 23 older adults (10 cognitively intact, 6 with amnestic mild cognitive impairment, 7 with AD). [(18)F]FDDNP-PET signal was highly correlated with cognitive performance, even in cognitively intact subjects. Animations of [(18)F]FDDNP signal growth with decreased cognition across all subjects (http://www.loni.ucla.edu/ approximately thompson/FDDNP/video.html) mirrored the classic Braak and Braak trajectory in lateral temporal, parietal, and frontal cortices. Regions in which cognitive performance was significantly correlated with [(18)F]FDDNP signal include those that deteriorate earliest in AD, suggesting the potential utility of [(18)F]FDDNP for early diagnosis.

[A patient with early Alzheimer's disease who showed improvement of cognitive function and cerebral perfusion by combined therapy of nilvadipine and PPAR gamma agonists]

A 76-year-old man was referred to our hospital because of memory impairment. He was diagnosed as having early Alzheimer's disease, in addition to hypertension and type II diabetes mellitus. Nilvadipine (a Ca-channel blocker), telmisartan (an angiotension II receptor blocker), and pioglitazone (an insulin sensitizer) were administered for the control of the hypertension and diabetes. After 6 months of treatment, the scores on verbal fluency (animals and vegetables/60 seconds) and frontal assessment battery of the patient improved despite no significant changes on the Mini-Mental State Examination and Alzheimer's Disease Assessment Scale. Moreover, follow-up examination of SPECT demonstrated an improvement of cerebral perfusion in the frontal and temporoparietal regions. In addition to nilvadipine, a highly lipophilic Ca channel antagonist agent that easily penetrates the central nervous system, PPARgamma agonists, such as pioglitazone and termisartan, may have had favourable effects on cognitive function and cerebral perfusion in this patient.

Language performance in Alzheimer's disease and mild cognitive impairment: a comparative review

Mild cognitive impairment (MCI) manifests as memory impairment in the absence of dementia and progresses to Alzheimer's disease (AD) at a rate of around 15% per annum, versus 1-2% in the general population. It thus constitutes a primary target for investigation of early markers of AD. Language deficits occur early in AD, and performance on verbal tasks is an important diagnostic criterion for both AD and MCI. We review language performance in MCI, compare these findings to those seen in AD, and identify the primary issues in understanding language performance in MCI and selecting tasks with diagnostic and prognostic value.

Patterns of neuropsychological impairment in MCI patients with small subcortical infarcts or hippocampal atrophy

We investigated whether MCI patients with hippocampal atrophy or multiple subcortical infarcts demonstrate neuropsychological patterns and markers considered typical of Alzheimer's disease (AD) and of vascular dementia (VD), respectively. An extensive neuropsychological battery, including tests of memory, visual-spatial and executive functions, language, attention, praxis and psychomotor speed, was administered to 36 mild cognitive impairment (MCI) patients with hippocampal atrophy and 41 MCI patients with multiple subcortical infarcts. Both groups of MCI patients were very mildly impaired and well matched in terms of MMSE scores. A clear, disproportionately severe, episodic memory disorder was observed in MCI patients with hippocampal atrophy. A less specific neuropsychological profile, consisting of impairment on an Action Naming task that is sensitive to frontal lobe lesions, was observed in MCI patients with multiple subcortical infarcts. In MCI patients, a disproportionately severe episodic memory impairment strongly points to an Alzheimer's type brain pathology, whereas the prevalence of executive deficits and other frontal lobe symptoms are a much weaker diagnostic marker of small vessel subcortical disease.

Memory and cognition in preclinical dementia: what we know and what we do not know

This overview focuses on the cognitive transition between normal aging and dementia. Numerous studies indicate that individuals who will go on to develop dementia show cognitive deficits many years before the time at which a clinical diagnosis could be rendered. The degree of preclinical impairment is remarkably similar for tasks assessing episodic memory, executive functioning, and perceptual speed, consistent with the view that multiple brain alterations occur prior to clinical disease onset. Although most research in this area has dealt with Alzheimer disease (AD), several recent reports indicate that the pattern of preclinical impairment is very similar in the second largest dementia disorder, vascular dementia (VaD). This is important because currently the possibility for interventions to postpone disease onset is greater in VaD than in AD. Despite pronounced preclinical cognitive deficits in dementia, the performance distributions between cases and controls are largely overlapping, hampering the ability to identify high-risk individuals. To alleviate this problem, future research should evaluate hybrid models for the prediction of dementia. In such models, multiple indicators of cognitive functioning should be included along with markers from other domains that have been linked to subsequent dementia (such as brain imaging, genetics, and lifestyle variables). To the extent that these categories of variables add unique variance, classification accuracy will increase and the overlap in performance scores between incident cases and controls will decrease, thereby enhancing clinical usefulness. This approach would also facilitate the examination of interactive effects among classes of preclinical markers.