Verbal fluency in dementia of frontal lobe type and dementia of Alzheimer type

Letter and Category Fluency: Normative Data for Lebanese Older Adults

Background: Verbal fluency tasks are frequently used for neuropsychological assessment in clinical practice and research. It consists of two tasks namely category and letter fluency tests. Objective: To determine normative values in category (animals, vegetables, fruits) and letter fluency [Mim () “M”, Alif () “A”, Baa () “B”] tasks in Arabic language in 60 s. Methods: This study was a cross-sectional national survey and included 859 community-dwelling, cognitively intact Lebanese residents aged ≥55 years. Norms were presented according to age (55–64 years, 65–74 years, ≥75 years), sex and level of education (illiterate, no diploma, primary certificate, baccalaureate or higher). Results: Level of education had the most significant positive effect on verbal fluency tasks performance amongst Lebanese older adults. The negative effect of older age was more prominent in the category fluency task compared to the letter fluency task. Women outperformed men in vegetables and fruits categories. Conclusion: This study provides clinicians with normative scores of category and letter fluency tests, which can be used for neuropsychological assessment of older Lebanese patients being evaluated for cognitive disorders.

Association Between Cerebral Microbleeds and Circulating Levels of Mid-Regional Pro-Adrenomedullin

Background: Mid-regional pro-adrenomedullin (MR-proADM) is a novel biomarker for cognitive decline based on its association with cerebral small vessel disease (SVD). Cerebral microbleeds (MBs) are characteristic of SVD; however, a direct association between MR-proADM and MBs has not been explored. Objective: We aimed to examine whether circulating levels of MR-proADM are associated with the identification of MBs by brain magnetic resonance imaging (MRI) and whether this association could be linked with cognitive impairment. Methods: In total, 214 participants (mean age: 75.9 years) without history of cerebral infarction or dementia were prospectively enrolled. All participants underwent brain MRI, higher cognitive function testing, blood biochemistry evaluation, lifestyle examination, and blood MR-proADM measurement using a time-resolved amplified cryptate emission technology assay. For between-group comparisons, the participants were divided into two groups according to whether their levels of MR-proADM were normal (<  0.65 nmol/L) or high (≥0.65 nmol/L). Results: The mean MR-proADM level was 0.515±0.127 nmol/L. There were significant between-group differences in age, hypertension, and HbA1c levels (p <  0.05). In the high MR-proADM group, the MR-proADM level was associated with the identification of MBs on brain MR images and indications of mild cognitive impairment (MCI). In participants with ≥3 MBs and MCI, high MR-proADM levels remained a risk factor after multivariate adjustment (OR: 2.94; p <  0.05). Conclusion: High levels of MR-proADM may be a surrogate marker for the early detection of cognitive decline associated with the formation of cerebral MBs. This marker would be valuable during routine clinical examinations of geriatric patients.

Graph Theoretical Analysis of Semantic Fluency in Patients with Parkinson’s Disease

Semantic fluency is the ability to name items from a given category within a limited time, which relies on semantic memory, working memory, and executive function. Semantic disfluency is a common problem in Parkinson's disease (PD) and Alzheimer's disease (AD). We demonstrated a graph theoretical analysis of semantic fluency in patients with PD (N = 86), patients with AD (N = 40), and healthy controls (HC, N = 88). All participants completed a standard animal fluency test. Their verbal responses were recorded, transcripted, and transformed into directed speech graphs. Patients with PD generated fewer correct words than HC and more correct words than patients with AD. Patients with PD showed higher density, shorter diameter, and shorter average shortest path length than HC, but lower density, longer diameter, and longer average shortest path length than patients with AD. It suggests that patients with PD produced relatively smaller and denser speech graphs. Moreover, in PD, the densities of speech graphs correlated with the severity of non-motor symptoms, but not the severity of motor symptoms. The graph theoretical analysis revealed new features of semantic disfluency in patients with PD.

The Assessment of Visuospatial Skills and Verbal Fluency in the Diagnosis of Alzheimer's Disease

BACKGROUND

In the diagnosis of Alzheimer's disease (AD), examining memory is predominant. Our aim was to analyze the potential role of various cognitive domains in the cognitive evaluation of AD.

METHODS

In total, 110 individuals with clinically defined AD and 45 healthy control participants underwent neuropsychological evaluation including Addenbrooke's Cognitive Examination (ACE). Patients with AD were selected in three groups based on disease duration in years (Group 1: ≤2 years, n = 36; Group 2: 2-4 years, n = 44; Group 3: ≥4 years, n = 30). Covariance-weighted intergroup comparison was performed on the global cognitive score and subscores of cognitive domains. Spearman's rho was applied to study the correlation between cognitive subscores and disease duration. The Wilcoxon signed-rank test was used for within-group analysis among ACE cognitive subscores.

RESULTS

Significant difference was found between ACE total scores among groups (χ2 = 119.1; p < 0.001) with a high negative correlation (p < 0.001; r = -0.643). With a longer disease duration, all the subscores of ACE significantly decreased (p-values < 0.001). The visuospatial score showed the strongest negative correlation with disease duration with a linear trajectory in decline (r = -0.85). In the early phase of cognitive decline, verbal fluency was the most impaired cognitive subdomain (normalized value = 0.64), and it was significantly reduced compared to all other subdomains (p-values < 0.05).

CONCLUSION

We found that the impairment of verbal fluency is the most characteristic feature of early cognitive decline; therefore, it might have crucial importance in the early detection of AD. Based on our results, the visuospatial assessment might be an ideal marker to monitor the progression of cognitive decline in AD.

A Comparison Between the Performances of Verbal and Nonverbal Fluency Tests in Discriminating Between Mild Cognitive Impairments and Alzheimer’s Disease Patients and Their Brain Morphological Correlates

Background and Purpose

Methods

Results

Conclusions

The protective impact of education on brain structure and function in Alzheimer's disease

BACKGROUND

The Cognitive Reserve (CR) theory posits that brains with higher reserve can cope with more cerebral damage to minimize clinical manifestations. The aim of this study was to examine the effect of education (CR proxy) on brain structure and function in Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) patients and in cognitively healthy elderly (HC) individuals.

METHODS

Fifty-seven AD patients, 57 aMCI patients and 48 HCs were included to investigate the relationships between education years and gray matter volume (GMV), regional homogeneity (ReHo) and functional connectivity (FC) in brain regions to show associations with both structure and function. Taking the severity of the disease into account, we further assessed the relationships in AD stratified analyses.

RESULTS

In AD group, the GMV of the dorsal anterior cingulate cortex (dACC) and ReHo in the left inferior temporal cortex (ITC) were inversely associated with education years, after adjustment for age, sex, Mini-Mental State Examination (MMSE), and total intracranial volume or head motion parameters. Seed-based FC analyses revealed that education years were negatively correlated with the FC between the left anterior ITC and left mid frontal cortex as well as right superior frontal cortex and right angular gyrus. Stratified analyses results indicated that this negative relation between education and GMV, ReHo, FC was mainly present in mild AD, which was attenuated in moderate AD and aMCI groups.

CONCLUSIONS

Our results support the CR theory, and suggest that CR may be protective against AD related brain pathology at the early stage of clinical dementia. These findings could provide the locus of CR-related functional brain mechanisms and a specific time-window for therapeutic interventions to help AD patients to cope better with the brain pathological damage by increasing CR.

Alzheimer’s Dementia Recognition From Spontaneous Speech Using Disfluency and Interactional Features

Alzheimer’s disease (AD) is a progressive, neurodegenerative disorder mainly characterized by memory loss with deficits in other cognitive domains, including language, visuospatial abilities, and changes in behavior. Detecting diagnostic biomarkers that are noninvasive and cost-effective is of great value not only for clinical assessments and diagnostics but also for research purposes. Several previous studies have investigated AD diagnosis via the acoustic, lexical, syntactic, and semantic aspects of speech and language. Other studies include approaches from conversation analysis that look at more interactional aspects, showing that disfluencies such as fillers and repairs, and purely nonverbal features such as inter-speaker silence, can be key features of AD conversations. These kinds of features, if useful for diagnosis, may have many advantages: They are simple to extract and relatively language-, topic-, and task-independent. This study aims to quantify the role and contribution of these features of interaction structure in predicting whether a dialogue participant has AD. We used a subset of the Carolinas Conversation Collection dataset of patients with AD at moderate stage within the age range 60–89 and similar-aged non-AD patients with other health conditions. Our feature analysis comprised two sets: disfluency features, including indicators such as self-repairs and fillers, and interactional features, including overlaps, turn-taking behavior, and distributions of different types of silence both within patient speech and between patient and interviewer speech. Statistical analysis showed significant differences between AD and non-AD groups for several disfluency features (edit terms, verbatim repeats, and substitutions) and interactional features (lapses, gaps, attributable silences, turn switches per minute, standardized phonation time, and turn length). For the classification of AD patient conversations vs. non-AD patient conversations, we achieved 83% accuracy with disfluency features, 83% accuracy with interactional features, and an overall accuracy of 90% when combining both feature sets using support vector machine classifiers. The discriminative power of these features, perhaps combined with more conventional linguistic features, therefore shows potential for integration into noninvasive clinical assessments for AD at advanced stages.

Changes in Cortical Thickness Are Associated With Cognitive Ability in Postoperative School-Aged Children With Tetralogy of Fallot

In children with tetralogy of Fallot (TOF), there is a risk of brain injury even if intracardiac deformities are corrected. This population follow-up study aimed to identify the correlation between cerebral morphology changes and cognition in postoperative school-aged children with TOF. Resting-state functional magnetic resonance imaging (rs-fMRI) and the Wechsler Intelligence Scale for Children–Chinese revised edition (WISC-CR) were used to assess the difference between children with TOF and healthy children (HCs). Multiple linear regression showed that the TOF group had a lower verbal intelligence quotient (VIQ, 95.000 ± 13.433, p = 0.001) than the HC group and that VIQ had significant positive correlations with the cortical thickness of both the left precuneus (p < 0.05) and the right caudal middle frontal gyrus (p < 0.05) after adjustment for preoperative SpO2, preoperative systolic blood pressure (SBP), preoperative diastolic blood pressure (DBP) and time of aortic override (AO). Our results suggested that brain injury induced by TOF would exert lasting effects on cortical and cognitive development at least to school age. This study provides direct evidence of the relationship between cortical thickness and VIQ and of the need for strengthened verbal training in school-aged TOF patients after corrective surgery.

Intrusion errors during verbal fluency task in amyotrophic lateral sclerosis

BACKGROUND

Numerous studies have noted the presence of a dysexecutive component of the ALS-FTD. The most widely replicated result refers to the significantly reduced verbal fluency of ALS patients when compared to healthy people. As ALS patients have motor alterations that interfere with production, qualitative studies have the advantage of being independent of the degree of motor disability and revealing patients' cognitive state. This study examined the production differences between 42 ALS patients who presented with different degrees of dementia and motor impairment and 42 healthy people. Production processes were studied by extending the administration time of a letter fluency task to 2 minutes for the phonemic verbal fluency (PVF) and semantic verbal fluency (SVF) categories. This ensured that the qualitative aspects of verbal fluency were addressed, paying special attention to the new perseverations and intrusions, as well as any clinical correlates that may exist.

RESULTS

The ALS patients produced a significantly lower number of responses in PVF (p = .017) and SVF (p = .008). The rest of the indicators for frontal lobe alteration also suggested the existence of a dysfunction. The most remarkable results were the number of intrusions on the PVF task, which was much higher in the ALS group (p = .002). However, the number of perseverations did not differ significantly.

CONCLUSIONS

This study highlights the value of intrusions in addressing cognitive deterioration in ALS patients. This deterioration seems to be independent of the degree of motor impairment and of behavioural alterations. Therefore, the value of the intromissions on the verbal fluency task was highlighted as an indicator of a new cognitive alteration, which can be easily evaluated, even retrospectively.

Verbal fluency in schizophrenia: The role of semantic clustering in category instance generation

The aim of this study was to determine whether schizophrenic patients' impairment in semantic verbal fluency tasks is due to difficulties in organizing their search or, in other words, in organizing output in terms of clusters of meaningfully related words. Consecutive association of words belonging to subcategories of the semantic task was defined as semantic clustering. A categorical verbal fluency task was first administered to 100 healthy subjects and then to 22 schizophrenic patients and 22 healthy subjects matched for sex, age and education. In the normal population, semantic clustering was found to be involved in word generation. A large number of semantic clusters indicated efficient organization of semantic knowledge and led to better word production. Schizophrenic patients showed impaired verbal fluency and generated a smaller number of semantic clusters than the control subjects. These findings point to a defect in self-initiation of semantic categorization in schizophrenia.

Polymorphism in the LASP1 gene promoter region alters cognitive functions of patients with schizophrenia

Schizophrenia's pathogenesis remains elusive. Cognitive dysfunction is the endophenotype and outcome predictor of schizophrenia. The LIM and SH3 domain protein (LASP1) protein, a component of CNS synapses and dendritic spines, has been related to the N-methyl-D-aspartate receptor (NMDAR) dysfunction hypothesis and schizophrenia. A single-nucleotide polymorphism (rs979607) in the LASP1 gene promoter region has been also implicated in schizophrenia susceptibility. The aim of this study was to investigate the role of the LASP1 rs979607 polymorphism in the cognitive functions of patients with schizophrenia. Two hundred and ninety-one Han Taiwanese patients with schizophrenia were recruited. Ten cognitive tests and two clinical rating scales were assessed. The scores of cognitive tests were standardized to T-scores. The genotyping of the LASP1 rs979607 polymorphism was performed using TaqMan assay. Among the 291 patients, 85 were C/C homozygotes of rs979607, 141 C/T heterozygotes, and 65 T/T homozygotes, which fitted the Hardy-Weinberg equilibrium. After adjusting age, gender, and education with general linear model, the C/C homozygotes performed better than C/T heterozygotes in overall composite score (p = 0.023), Category Fluency test (representing processing speed and semantic memory) (p = 0.045), and Wechsler Memory Scale (WMS)-III backward Spatial Span test (p = 0.025), albeit without correction for multiple comparisons for the latter two individual tests. To the best of our knowledge, this is the first study suggesting that the genetic variation of LASP1 may be associated with global cognitive function, category verbal fluency, and spatial working memory of patients with schizophrenia. The finding also lends support to the NMDAR dysfunction hypothesis of schizophrenia. More studies with longitudinal designs are warranted.

How to Assess Executive Functions in a Low-Educated and Multicultural Population Using a Switching Verbal Fluency Test (the TFA-93) in Neurodegenerative Diseases?

Few neuropsychological tests are available to assess executive dysfunction in low-educated and multicultural populations. To address this issue, the TFA-93, a switching verbal fluency test to assess cognitive flexibility, was administered to 70 healthy controls, 57 patients with a clinical diagnosis of Alzheimer's disease, and 21 with a clinical diagnosis of a neurodegenerative disease associated with frontal disorders. Most of the participants were low-educated and nonnative French speakers. The TFA-93 comprises 2 categorical fluency tasks (animals and fruits) and a fluency task in which participants have to switch between animals and fruits. Correct responses and errors were collected, and a flexibility index expressed the switching cost. Results showed that correct responses were lower, and the switching cost was greater in both patient groups. In low-educated and multicultural populations, the TFA-93 seems to be a good alternative to assess flexibility compared to the standard neuropsychological tools based on academic abilities.

Verbal fluency tests: Normative data for the Latin American Spanish speaking adult population

OBJECTIVE

To generate normative data for the Verbal Fluency Tests across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate.

METHOD

The sample consisted of 3,977 healthy adults who were recruited from Argentina, Bolivia, Chile, Cuba, El Salvador, Guatemala, Honduras, Mexico, Paraguay, Peru, and, Puerto Rico. Each subject was administered the Verbal Fluency Test as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms.

RESULTS

The final multiple linear regression models for the letter F explained 8-30% of the variance, 7-32% for letter A, 8-32% for the letter S, and 16-43% for the animal category in Verbal Fluency Test scores. Although t-tests showed significant differences between men and women on the Verbal Fluency Test, they did not have an effect size larger than 0.3. As a result, gender-adjusted norms were not generated.

CONCLUSIONS

This is the first normative multicenter study conducted in Latin America aiming to create norms for the Verbal Fluency Test; this study will have important outcomes for the future of neuropsychology in the region.

Pork and Chicken Meals Similarly Impact on Cognitive Function and Strength in Community-Living Older Adults: A Pilot Study

A pilot quasi-experimental study investigated whether provision of pork, a rich source of thiamin, as the main protein source in meals four times/week for 12 weeks resulted in improved muscle mass, body strength, and cognitive function in community-living older adults compared to similar meals containing chicken. Retirement villages were randomized to receive pre-prepared frozen meals containing either pork or chicken. Dietary intake was assessed by three-day food records and cognitive domains assessed using validated tests. Hand grip strength was measured and lower extremity performance assessed by the sit-to-stand test, get-up-and-go test and six-minute walk test. Forty-eight volunteers participated (78.2 ± 6.2 y). In linear mixed models, controlling for baseline physical activity and dietary protein and energy intake, no differences were found between pork (n = 19) and chicken (n = 12) groups. The chicken group had improved Rey Auditory Verbal Learning test scores (verbal learning and memory) at six weeks (p < 0.001). Provision of four pork meals a week did not result in improvements in cognitive function, nor measures of strength or physical function, compared to those receiving chicken meals in healthy older adults. This suggests that merely changing the type of dietary protein provided by meat does not impact physical or cognitive function.

Functional MRI evidence for the decline of word retrieval and generation during normal aging

This fMRI study aimed to explore the effect of normal aging on word retrieval and generation. The question addressed is whether lexical production decline is determined by a direct mechanism, which concerns the language operations or is rather indirectly induced by a decline of executive functions. Indeed, the main hypothesis was that normal aging does not induce loss of lexical knowledge, but there is only a general slowdown in retrieval mechanisms involved in lexical processing, due to possible decline of the executive functions. We used three tasks (verbal fluency, object naming, and semantic categorization). Two groups of participants were tested (Young, Y and Aged, A), without cognitive and psychiatric impairment and showing similar levels of vocabulary. Neuropsychological testing revealed that older participants had lower executive function scores, longer processing speeds, and tended to have lower verbal fluency scores. Additionally, older participants showed higher scores for verbal automatisms and overlearned information. In terms of behavioral data, older participants performed as accurate as younger adults, but they were significantly slower for the semantic categorization and were less fluent for verbal fluency task. Functional MRI analyses suggested that older adults did not simply activate fewer brain regions involved in word production, but they actually showed an atypical pattern of activation. Significant correlations between the BOLD (Blood Oxygen Level Dependent) signal of aging-related (A > Y) regions and cognitive scores suggested that this atypical pattern of the activation may reveal several compensatory mechanisms (a) to overcome the slowdown in retrieval, due to the decline of executive functions and processing speed and (b) to inhibit verbal automatic processes. The BOLD signal measured in some other aging-dependent regions did not correlate with the behavioral and neuropsychological scores, and the overactivation of these uncorrelated regions would simply reveal dedifferentiation that occurs with aging. Altogether, our results suggest that normal aging is associated with a more difficult access to lexico-semantic operations and representations by a slowdown in executive functions, without any conceptual loss.

Cognition and neuropsychiatry in behavioral variant frontotemporal dementia by disease stage

OBJECTIVE

To characterize the cognitive and neuropsychiatric symptoms of patients with behavioral variant frontotemporal dementia (bvFTD) over the natural course of the disease.

METHODS

We examined the initial and subsequent neuropsychological test performance and neuropsychiatric symptoms in a large cohort of patients with bvFTD (n = 204) across progressive stages of disease as measured by the Clinical Dementia Rating (CDR). We also compared cognitive and neuropsychiatric impairments of patients with bvFTD to those of an age-matched cohort with Alzheimer disease (AD) dementia (n = 674).

RESULTS

At the earliest stage (CDR = 0.5), patients with bvFTD had profound neuropsychiatric disturbances, insensitivity to errors, slower response times, and poor naming, with intact attention span, memory, and facial affect naming. Tests continuing to show progressive, statistically significant stepwise declines after the CDR = 1 stage included free recall, visuoconstruction, set-shifting, error insensitivity, semantic fluency, design fluency, emotion naming, calculations, confrontation naming, syntax comprehension, and verbal agility. At CDR = 0.5, patients with bvFTD significantly outperformed patients with AD in episodic memory and were faster in set-shifting, while scoring quantitatively worse in lexical fluency, emotion naming, and error sensitivity. The overall rate of disease progression in bvFTD was more rapid than in AD.

CONCLUSION

There are distinct patterns of cognitive deficits differentiating the earlier and later disease stages in bvFTD, with the pattern of cognitive decline revealing in greater detail the natural history of the disease. These cognitive symptoms are readily apparent clinical markers of dysfunction in the principal brain networks known to undergo molecular and anatomical changes in bvFTD, thus are important indicators of the evolving pathology in individual patients.

Consumption of anthocyanin-rich cherry juice for 12 weeks improves memory and cognition in older adults with mild-to-moderate dementia

PURPOSE

Dietary flavonoids, including anthocyanins, may positively influence cognition and may be beneficial for the prevention and treatment of dementia. We aimed to assess whether daily consumption of anthocyanin-rich cherry juice changed cognitive function in older adults with dementia. Blood pressure and anti-inflammatory effects were examined as secondary outcomes.

METHODS

A 12-week randomised controlled trial assessed cognitive outcomes in older adults (+70 year) with mild-to-moderate dementia (n = 49) after consumption of 200 ml/day of either a cherry juice or a control juice with negligible anthocyanin content. Blood pressure and inflammatory markers (CRP and IL-6) were measured at 6 and 12 weeks. ANCOVA controlling for baseline and RMANOVA assessed change in cognition and blood pressure.

RESULTS

Improvements in verbal fluency (p = 0.014), short-term memory (p = 0.014) and long-term memory (p ≤ 0.001) were found in the cherry juice group. A significant reduction in systolic (p = 0.038) blood pressure and a trend for diastolic (p = 0.160) blood pressure reduction was evident in the intervention group. Markers of inflammation (CRP and IL-6) were not altered.

CONCLUSION

Inclusion of an anthocyanin-rich beverage may be a practical and feasible way to improve total anthocyanin consumption in older adults with mild-to-moderate dementia, with potential to improve specific cognitive outcomes.

Treatment effects in multiple cognitive domains in Alzheimer's disease: a two-year cohort study

Introduction

Despite widespread use of second-generation cholinesterase inhibitors for the symptomatic treatment of Alzheimer’s disease (AD), little is known about the long term effects of cholinergic treatment on global cognitive function and potential specific effects in different cognitive domains. The objectives of this study were to determine the association between cholinergic treatment and global cognitive function over one and two years in a cohort of patients with mild or moderate AD and identify potential differences in domain-specific cognitive outcomes within this cohort.

Methods

A cohort of patients meeting the revised National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria for mild or moderate AD, including patients both on treatment with a cholinesterase inhibitor and untreated controls (treated = 65, untreated = 65), were recruited from the Cognitive Neurology Clinic at Sunnybrook Health Sciences Centre, as part of the Sunnybrook Dementia Study. Patients were followed for one to two years and underwent standardized neuropsychological assessments to evaluate global and domain-specific cognitive function. Associations between cholinesterase inhibitor use and global and domain-specific cognitive outcome measures at one and two years of follow-up were estimated using mixed model linear regression, adjusting for age, education, and baseline mini mental state examination (MMSE).

Results

At one year, treated patients showed significantly less decline in global cognitive function, and treatment and time effects across tests of executive and visuospatial function. At two years, there was a significant trend towards less decline in global cognition for treated patients. Moreover, treated patients showed significant treatment and time effects across tests of executive functioning, memory, and visuospatial function.

Conclusions

The present study offers two important contributions to knowledge of the effectiveness of cholinesterase inhibitor treatment in patients with mild-moderate AD: 1) that second-generation cholinesterase inhibitors demonstrate long-term effectiveness for reducing global cognitive decline over one to two years of follow-up, and 2) that decline in function for cognitive domains, including executive function, memory, and visuospatial skill that are primarily mediated by frontal networks and by the cholinergic system, rather than memory, may be slowed by treatment targeting the cholinergic system.

[Verbal fluency among healthy elderly: a study of three complex verbal fluency tasks under healthy older people and patients with neurocognitive disorder or onset dementia of the Alzheimer type]

The aim of this study is to provide normative data for a phonological alternating task (FAT), a semantic alternating task (SAT) and an excluded letter task (ELT). The tasks were administered to 146 Flemish-speaking, cognitively healthy elderly. Data from 102 were used and were classified according to the significant variables. Subsequently, these tasks were administered to seven patients diagnosed with mild neurocognitive impairment (mild cognitive impairment, MCI) and seven patients with onset dementia of the Alzheimer type (DAT). Results of the standard study show that the level of education is a significant variable for all complex VFT and age for the SAT and the ELT, while age related deterioration is highest for the ELT. The error rate is highest for the ELT and lowest for the SAT. Analysis of the time duration shows that data should be collected for at least 2 min. The patients scored significantly lower than the normgroup of healthy adults. The error rate is highest for the SAT and lowest for the ELT.

Early detection of memory impairment in people over 65 years old consulting at Health Examination Centers for the French health insurance: the EVATEM protocol

BACKGROUND

Only half of those living with Alzheimer's disease in France are currently diagnosed, and only one patient in three is supported during the early stages of dementia. This study aims to evaluate three cognitive tests for their predictive ability to diagnose mild cognitive impairments and Alzheimer's disease and related disorders. For people aged 65 years or over, presenting with a memory complaint, these tests can be performed easily during a preventative consultation.

METHOD/DESIGN

The EVATEM (évaluation des troubles de l'équilibre et de la mémoire (evaluation of balance and memory problems)) cohort study was designed to prospectively assess the predictive value of tests for the diagnosis of mild cognitive impairments and Alzheimer's disease in elderly subjects aged 65 years or over. Subjects were recruited from three health examination centers that are part of the French health insurance system. If a memory complaint was identified (using a dedicated questionnaire), the five-word test, the cognitive disorders examination test and the verbal fluency test were administered during a preventative consultation. A memory consultation was performed at a University Hospital to diagnosis any potential cognitive disorder and a one-year follow-up consultation was also scheduled. We recorded 2041 cases of memory complaint at our Health Examination Centers. Cognitive tests were refused by 33.6% of people who had a memory complaint. The number of subjects sent to a University Hospital memory consultation was 832 and 74.5% of them completed this consultation. The study population therefore includes 620 subjects.

DISCUSSION

Tests for the early diagnosis of a mild cognitive impairment or Alzheimer's disease and related disorders should be used in centers dedicated to disease prevention. These should guide subjects with memory impairment to full memory consultations at hospitals and improve the access to early medical and behavioral support.

TRIAL REGISTRATION

ClinicalTrials.gov:NCT01316562.

Intracranial deep white matter lesions (DWLs) are associated with chronic kidney disease (CKD) and cognitive impairment: a 5-year follow-up magnetic resonance imaging (MRI) study

Stroke incidence and cognitive decline are related to progression of arteriosclerosis in intracranial DWLs. However, the relationships between DWLs and factors associated with their progression, including CKD, have not been fully elucidated using longitudinal MRI. Of 291 individuals (184 males, 107 females; age 66.9 ± 6.1 years) who had voluntarily participated in a hospital-based health check-up and underwent repeated brain MRI scans in 2003 and 2008, 273 were evaluated in this study. The DWL group included those having DWL without progression, and the DWL progression (DWLP) group included those having an increase in grade number according to the Fazekas classification. Unimpaired age-matched subjects with no brain MRI abnormalities constituted Group C. The Mini-Mental State Examination (MMSE) and verbal fluency tasks were used for objective cognitive evaluations according to the MR evaluation schedule in 2008. Associations between DWLs and vascular risk factors were examined. DWLP occurred in 9.2% of subjects. Compared to Group C subjects, DWL and DWLP group subjects had high odds ratios (ORs) for hypertension (HT) (2.23 and 2.92, respectively) and CKD (1.40 and 2.41, respectively). After adjustment for potential confounders, the ORs of CKD for DWLs remained significant (1.13 and 1.43, p<0.05). DWLs and DWLP were associated with low cognitive scale scores and increased CKD. In conclusion, CKD was associated with DWLs and DWLP as an independent risk factor and a lower level of cognitive function 5 years after CKD was identified. Successful CKD therapy may be expected to prevent DWLP.

The Philadelphia Brief Assessment of Cognition (PBAC): a validated screening measure for dementia

The Philadelphia Brief Assessment of the Cognition (PBAC) is a brief dementia-screening instrument. The PBAC assesses five cognitive domains: working memory/executive control; lexical retrieval/language; visuospatial/visuoconstructional operations; verbal/visual episodic memory; and behavior/social comportment. A revised version of the PBAC was administered to 198 participants including patients with Alzheimer's disease (AD) (n=46) and four groups of patients with frontotemporal dementia (FTD) syndromes: behavioral-variant FTD (bvFTD; n=65), semantic-variant primary progressive aphasia (PPA) (svPPA; n=22), non-fluent/agrammatic-variant PPA (nfaPPA; n=23), and corticobasal syndrome (CBS; n=42), and a group of normal controls (n=15). The total PBAC score was highly correlated with the MMSE. The criterion validity of the PBAC was assessed relative to standard neuropsychological test performance. Using standard neuropsychological test performance as a criterion, the total PBAC score accurately identified the presence and severity of dementia. Intra-class correlations between PBAC subscales and standard neuropsychological tests were highly significant. PBAC subscales demonstrated good clinical utility in distinguishing AD and FTD subtypes using receiver operating characteristic analysis and standard diagnostic performance statistics to determine optimal subscale cut scores. The PBAC is a valid tool and able to assesses differential patterns neuropsychological/behavioral impairment in a broad range of neurodegenerative conditions.

Differential effects of methylphenidate on problem solving in adults with ADHD

OBJECTIVE

Two studies were performed to assess both divergent and convergent thinking in adults with ADHD.

METHOD

The first study compared the problem-solving abilities of healthy participants (N = 144) and unmedicated adults with ADHD (N = 144). In the second study, problem-solving abilities of adults with diagnosed ADHD (N = 22) were examined twice, that is, on and off methylphenidate (MPH), and compared with the performance of a healthy control group (N = 22). Convergent thinking was measured using a Tower of London task, whereas divergent thinking was assessed using verbal fluency tasks.

RESULTS

Adults with ADHD off MPH displayed marked deficits of both divergent and convergent thinking. MPH treatment resulted in a marked improvement of convergent thinking, while no effect of medication was found regarding divergent thinking.

CONCLUSION

Pharmacological treatment of adults with ADHD revealed a differential effect of MPH on problem solving abilities.

Verbal fluency in Alzheimer's disease, Parkinson's disease, and major depression

OBJECTIVE

To compare verbal fluency among Alzheimer's disease, Parkinson's disease, and major depression and to assess the sociodemographic and clinical factors associated with the disease severity.

METHODS

Patients from an outpatient university center with a clinical diagnosis of Alzheimer's disease, Parkinson's disease or major depression were studied. Severity was staged using the Hoehn & Yahr scale, the Hamilton Depression scale and the Clinical Dementia Rating for Parkinson's disease, major depression, and Alzheimer's disease, respectively. All subjects were tested with the Mini-Mental State Examination, the digit span test, and the verbal fluency test (animals). We fit four types of regression models for the count variable: Poisson model, negative binomial model, zero-inflated Poisson model, and zero-inflated negative binomial model.

RESULTS

The mean digit span and verbal fluency scores were lower in patients with Alzheimer's disease (n = 34) than in patients with major depression (n = 52) or Parkinson's disease (n = 17) (p<0.001). The average number of words listed was much lower for Alzheimer's disease patients (7.2 words) compared to the patients presenting with major depression (14.6 words) or Parkinson's disease (15.7 words) (KW test = 32.4; p<0.01). Major depression and Parkinson's disease groups listed 44% (ROM = 1.44) and 48% (ROM = 1.48) more words, respectively, compared to those patients with Alzheimer's disease; these results were independent of age, education, disease severity and attention. Independently of diagnosis, age, and education, severe disease showed a 26% (ROM = 0.74) reduction in the number of words listed when compared to mild cases.

CONCLUSIONS

Verbal fluency provides a better characterization of Alzheimer's disease, major depression, and Parkinson's disease, even at later stages.

Neuropsychological changes in patients with primary lateral sclerosis

Primary lateral sclerosis (PLS) has been defined as rare, and the neuropsychological changes remain poorly defined. We studied 20 patients with a diagnosis of PLS. We carried out an extensive psychometric testing including a general assessment (memory, language, attention, visual-constructional ability and praxis) and a more specific assessment of prefrontal and premotor cortex functions in order to characterize the neuropsychological profile of the patients compared to matched controls, and explore executive functions and premotor cortex functions. None of the PLS patients was demented but they all presented memory deficits reflecting an executive dysfunction. All patients but three had signs of premotor and/or prefrontal cortex deficits. The cognitive impairment in PLS, specifically related to a frontal lobe dysfunction, seems qualitatively similar to ALS. Our results suggest a patchy distribution of cortical involvement in PLS but it remains difficult to draw any definite conclusion as to the spatio-temporal progression of the disease into the different regions of the frontal lobe.

Resuscitation at birth and cognition at 8 years of age: a cohort study

BACKGROUND

Mild cerebral injury might cause subtle defects in cognitive function that are only detectable as the child grows older. Our aim was to determine whether infants receiving resuscitation after birth, but with no symptoms of encephalopathy, have reduced intelligence quotient (IQ) scores in childhood.

METHODS

Three groups of infants were selected from the Avon Longitudinal Study of Parents and Children: infants who were resuscitated at birth but were asymptomatic for encephalopathy and had no further neonatal care (n=815), those who were resuscitated and had neonatal care for symptoms of encephalopathy (n=58), and the reference group who were not resuscitated, were asymptomatic for encephalopathy, and had no further neonatal care (n=10 609). Cognitive function was assessed at a mean age of 8.6 years (SD 0.33); a low IQ score was defined as less than 80. IQ scores were obtained for 5953 children with a shortened version of the Weschler intelligence scale for children (WISC-III), the remaining 5529 were non-responders. All children did not complete all parts of the test, and therefore multiplied IQ values comparable to the full-scale test were only available for 5887 children. Results were adjusted for clinical and social covariates. Chained equations were used to impute missing values of covariates.

FINDINGS

In the main analysis at 8 years of age (n=5887), increased risk of a low IQ score was recorded in both resuscitated infants asymptomatic for encephalopathy (odds ratio 1.65 [95% CI 1.13-2.43]) and those with symptoms of encephalopathy (6.22 [1.57-24.65]). However, the population of asymptomatic infants was larger than that of infants with encephalopathy, and therefore the population attributable risk fraction for an IQ score that might be attributable to the need for resuscitation at birth was 3.4% (95% CI 0.5-6.3) for asymptomatic infants and 1.2% (0.2-2.2) for those who developed encephalopathy.

INTERPRETATION

Infants who were resuscitated had increased risk of a low IQ score, even if they remained healthy during the neonatal period. Resuscitated infants asymptomatic for encephalopathy might result in a larger proportion of adults with low IQs than do those who develop neurological symptoms consistent with encephalopathy.

FUNDING

Wellcome Trust.

The underlying mechanisms of verbal fluency deficit in frontotemporal dementia and semantic dementia

Verbal fluency tasks are commonly used to explore semantic memory and executive functions. The aim of this study was to gain a better understanding of the cognitive and neural mechanisms underlying verbal fluency impairment in the frontal variant of frontotemporal dementia (fv-FTD) and in semantic dementia (SD). Semantic and phonemic fluency tasks were performed by 36 fv-FTD and SD patients and 18 elderly controls. We also carried out a neuropsychological investigation of semantic memory, working memory and shifting and updating processes. We performed correlative and regression analyses of fluency scores and neuropsychological data. In addition, patients underwent a resting positron emission tomography examination, and statistical parametric mapping was used to establish correlations between resting-state FDG uptake in the whole brain and fluency scores for each patient group. Both patient groups displayed impaired performances on both fluency tasks compared with controls, but with different patterns. While fv-FTD patients scored higher than SD patients on semantic fluency, their performances on the phonemic task did not differ. Correlation and regression analyses clearly demonstrated that the fv-FTD patients' performances on both fluency tasks depended on their executive abilities, while those of the SD patients were hampered by the impairment of their semantic memory store. Correlations with resting FDG uptake were consistent with the results of the cognitive study. In fv-FTD, both fluency performances were related to the metabolism of the frontal lobes, while we observed significant correlations between performances on both fluency tasks and the left temporal lobe metabolism in SD.

Screening for frontotemporal dementias and Alzheimer's disease with the Philadelphia Brief Assessment of Cognition: a preliminary analysis

BACKGROUND

A neuropsychological screening instrument sensitive to neuropsychological deficits associated with Alzheimer's disease (AD) and patients with frontotemporal dementia (FTD) would be valuable for diagnostic evaluation.

METHODS

The Philadelphia Brief Assessment of Cognition (PBAC) assesses working memory/executive control, language, visuospatial operations, verbal/visual episodic memory, and behavior/social comportment and can be administered and scored in 15-20 min. Participants included 149 patients with AD and four groups of FTD patients - i.e., patients with a decline in social comportment, personality, and executive functioning (SOC/EXEC), semantic dementia (SemD), progressive nonfluent aphasia (PNFA), and corticobasal syndrome (CBS).

RESULTS

The total PBAC score correlated with the Mini-Mental State Examination. Between-group analysis of PBAC subscales and the results of logistic regression analyses produced substantial between-group differences, emphasizing the sensitivity of the test to differentiate dementia subtypes. AD patients were impaired on tests of episodic memory, SOC/EXEC patients were impaired on a measure of social comportment/behavioral disturbance, PNFA patients obtained low scores on tests of working memory/executive control, SemD patients obtained lower scores on language-mediated measures, and CBS patients were impaired on visuospatial/visual memory tests.

CONCLUSION

These data support the usefulness of the PBAC as a relatively brief screening test of overall dementia severity across a wide range of dementia patients.

Differential neuropsychological patterns of frontal variant frontotemporal dementia and Alzheimer's disease in a study of diagnostic concordance

Although the pathological hallmarks of Alzheimer's disease (AD) and frontal variant frontotemporal dementia (fvFTD) predict different cognitive patterns, many comparative neuropsychological studies showed no difference in the expected cognitive domains. Inconsistencies in diagnostic criteria, small cohorts of patients, and neuropsychological assessment may account for such findings. Moreover, discrepancies in memory and executive dysfunctions that are expected to distinguish AD and fvFTD may reflect the basic brain organization. Adhering to a strict concordance of clinical and neuroradiological criteria, we compared many patients with AD and fvFTD using a large neuropsychological battery. One hundred and thirty-nine patients with AD (n=89) or fvFTD (n=50) were retrospectively considered in order to verify the diagnostic congruence of clinical and neuroradiological aspects. On this basis, 117 patients with AD (n=77) or fvFTD (n=40) with similar duration and severity of dementia were selected. Ninety-one healthy subjects were also controlled. Mean scores in tests for abstract reasoning, planning, set shifting, initiative, verbal fluency, immediate and episodic memory, constructive, ideomotor and orofacial praxis, selective and divided attention, visuomotor coordination, and visual perception were evaluated. Separate analyses of variance and post hoc Bonferroni tests showed that, with respect to controls, both patient groups were significantly impaired in all neuropsychological tests. Compared to fvFTD patients, AD patients were significantly impaired in episodic memory, selective attention, visual perception, visuomotor coordination, and constructive praxis, whereas no differences were found in executive, intellective, and linguistic abilities between the two patient groups. Logistic regression analyses revealed that episodic memory significantly predicted the diagnosis of AD while no executive deficit was able to predict the diagnosis of fvFTD. To conclude, memory, attention, and visuoconstructive deficits may distinguish AD with respect to fvFTD, in accordance with the severe temporo-parietal-occipital degeneration characterizing AD, but no executive impairment is consistently able to identify a relative compromise in fvFTD. Executive functions impairments possibly reflect the altered spatial-temporal integration of the frontal lobes with different brain areas, which prevents a clear-cut cognitive-brain correlation.

Cognitive-behavioral profiles of neurodegenerative dementias: beyond Alzheimer's disease

The neurocognitive and behavioral profiles of vascular dementia and vascular cognitive impairment, dementia with Lewy bodies and Parkinson's disease with dementia, and dementia syndromes associated with frontotemporal lobar degenerations are compared and contrasted with Alzheimer's dementia (AD). Vascular dementia/vascular cognitive impairment is characterized by better verbal memory performance, worse quantitative executive functioning, and prominent depressed mood. Dementia with Lewy bodies and Parkinson's disease with dementia are equally contrasted with AD by defective processing of visual information, better performance on executively supported verbal learning tasks, greater attentional variability, poorer qualitative executive functioning, and the presence of mood-congruent visual hallucinations. The frontal variant of frontotemporal lobar degeneration (frontotemporal dementia) differs from AD by better multimodal retention on learning tasks, different patterns of generative word fluency, defective qualitative executive functioning, and by markedly impairment of comportment. For temporal variants of frontotemporal lobar degenerations, progressive aphasia and semantic dementia, worse language performance relative to AD is typically characteristic.

Neuropsychological deficits in frontotemporal dementia and Alzheimer's disease: a meta-analytic review

We sought to identify the cognitive tests that best discriminate between Alzheimer's disease (AD) and frontotemporal dementia (FTD). A comprehensive search of all studies examining the cognitive performance of persons diagnosed with AD and FTD, published between 1980 and 2006, was conducted. Ninety-four studies were identified, comprising 2936 AD participants and 1748 FTD participants. Weighted Cohen's d effect sizes, percentage overlap statistics, confidence intervals and fail-safe Ns were calculated for each cognitive test that was used by two or more studies. The most discriminating cognitive tests were measures of orientation, memory, language, visuomotor function and general cognitive ability. Although there were large and significant differences between groups on these measures, there was substantial overlap in the scores of the AD and FTD groups. Age, education, years since diagnosis and diagnostic criteria did not significantly contribute to the group differences. Given the large overlap in the test performance of persons diagnosed with AD and FTD, cognitive tests should be used cautiously and in conjunction with a medical history, behavioural observations, imaging and information from relatives when making differential diagnoses.

On the multivariate nature of brain metabolic impairment in Alzheimer's disease

We used principal component analysis to decompose functional images of patients with AD in orthogonal ensembles of brain regions with maximal metabolic covariance. Three principal components explained 38% of the total variance in a large sample of FDG-PET images obtained in 225 AD patients. One functional ensemble (PC2) included limbic structures from Papez's circuit (medial temporal regions, posterior and anterior cingulate cortex, thalamus); its disruption in AD patients was related to episodic memory impairment. Another principal component (PC1) illustrated major metabolic variance in posterior cerebral cortices, and patients' scores were correlated to instrumental functions (language and visuospatial abilities). PC3 comprised frontal, parietal, temporal and posteromedial (posterior cingulate and precuneus) cortices, and patients' scores were related to executive dysfunction and global cognitive impairment. The three main metabolic covariance networks converged in the posterior cingulate area that showed complex relationships with medial temporal structures within each PC. Individual AD scores were distributed as a continuum along PC axes: an individual combination of scores would determine specific clinical symptoms in each patient.

The frontal hypothesis of cognitive aging: factor structure and age effects on four frontal tests among healthy individuals

With 101 healthy aging adult participants, the authors investigated whether executive functions are a unitary concept. The authors established the factor structure of the Wisconsin Card Sorting Test (WCST; E. A. Berg, 1948), the Stroop color and word test (C. J. Golden, 1978), verbal fluency using the Controlled Oral Word Association Test (COWAT; Benton, 1967), and the Digits Backwards subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981). The authors also evaluated the extent to which age and other demographic variables predicted common underlying properties of these frontal tests. Results revealed an age-related decline in executive abilities differentially reflected by the selected tasks. These data suggest caution using the COWAT to evaluate executive abilities in older people. The authors interpret findings to support the unitary view of executive abilities and the executive decline proposed by the frontal hypothesis.

Analysis of brief language tests in the detection of cognitive decline and dementia

Lexical access difficulties are frequent in normal aging and initial stages of dementia.Verbal fluency tests are valuable to detect cognitive decline, evidencing lexico-semantic and executive dysfunction.

Étude de la planification de l’action au moyen du test du plan du zoo dans la maladie d’Alzheimer

INTRODUCTION

Executive dysfunction is regularly reported in patients with Alzheimer's disease. Nevertheless few studies have focused on planning ability in this neurodegenerative disease.

OBJECTIVES

This study aimed to investigate the formulation and the execution of plans in Alzheimer's disease using an ecological planning subtask derived from the Behavioural Assessment of the Dysexecutive Syndrome test battery, the "Zoo Map Test". There are two trials. The first trial consists of a "high demand" version of the subtask in which the subjects must plan in advance the order in which they will visit designated locations in a zoo (formulation level). In the second, or "low demand" version, the subject is simply required to follow a concrete externally imposed strategy to reach the locations to visit (execution level). The test was given to 16 patients with Alzheimer's disease and 13 normal elderly subjects.

RESULTS

The two way ANOVAs mainly showed more difficulties in patients with Alzheimer's disease than in healthy elderly in both conditions. The difference between formulation and execution was greater in patients with Alzheimer's disease than in healthy elderly. Planning impairments mainly correlated with behavioural changes (in particular motivational changes) observed by patient's relatives.

CONCLUSION

These results suggest that patients with Alzheimer's disease have some problems to mentally develop logical strategies and to execute complex predetermined plans, which are partially related to behavioural changes.

Age-related differences in performance of phonemic verbal fluency measured by Controlled Oral Word Association Task (COWAT): a meta-analytic study

Meta-analytical procedures were used to examine the research findings on age-related changes in phonemic verbal fluency measured by the Controlled Oral Word Association Task (COWAT). Data from 26 studies comparing adults from different age ranges were analyzed. An effect of aging was found in almost all age comparisons especially after 40 years of age. Results revealed a decline of this verbal ability after 60 years, which accelerates through the late 80s. Gender may influence COWAT performance after the sixth decade, favoring women over men. These results may be important in clinical situations where COWAT is used to assert pathological changes.

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.

A longitudinal study of quantitative and qualitative features of category verbal fluency in incident Alzheimer's disease subjects: results from the PAQUID study

Category fluency tests were administered at baseline and after 3 and 5 years on two subgroups of subjects from a population-based cohort of elderly subjects: 52 cases of incident possible and probable Alzheimer's disease (AD) and 104 age- and education-matched subjects who remained nondemented. Quantitative and qualitative features of category fluency were assessed to determine how changes occur within 5 years of the diagnosis of AD. Consistent with previous results, we found that the number of words produced on this task was already significantly lower 5 years before the diagnosis in subjects with incident AD as compared with subjects who did not become demented. However, the rate of repetitions only significantly increased in AD subjects at the time of diagnosis, and the rate of intrusions remained low and not significantly different between the two groups. Thus, it is concluded that dysfunction in cognitive processes underlying repetitions and intrusions in verbal fluency tasks, such as inhibitory processes and working memory, may not be the main cause of the very early deficit in verbal fluency occurring in AD.

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.

Age-related psychomotor slowing as an important component of verbal fluency

Generalized psychomotor slowing is a characteristic of normal aging, and there is evidence suggesting that this feature is also central in dementia. The present article aims to evaluate the importance of psychomotor slowing as a factor underlying changes in the performance of verbal fluency tasks in normal and pathological aging. In study 1 reading and handwriting speed were used to predict performance on written and oral verbal fluency tasks (VFTs) in healthy elderly subjects (n = 20) and in patients of the Alzheimer type disease (n = 20). In study 2, spectrographic techniques were used to obtain reaction times, average of voice intensity and duration of single word production in young individuals (n = 20), healthy elderly subjects (n = 20), and in patients of the Alzheimer type disease (n = 7). Additionally, duration of single word production were also obtained. The results suggest that age-related psychomotor decline in word production speed is an important determinant of VFT.