The frontal assessment battery does not differentiate frontotemporal dementia from Alzheimer's disease

Visuospatial impairment in dementia: a new index to improve the clinical diagnosis of Alzheimer's disease

BACKGROUND

The differential diagnosis between Alzheimer's disease (AD) and other causes of dementia is essential but challenging. Therefore, there is an increasing need for early, reliable, and non-invasive tests to distinguish between different forms of dementia.

AIMS

To determine whether neuropsychological tests assessing visuospatial function can improve confidence in the clinical diagnosis of AD.

METHODS

Retrospective observational single-center cohort study involving all patients consecutively referred to our outpatient clinic for cognitive disorders who underwent neuropsychological assessment between 2013 and 2018. In addition to demographic and functional variables, each patient underwent neuropsychological tests to assess cognitive performance, memory, and executive, language, and visuospatial ability, according to clinical protocols. The clinical diagnosis of cognitive disorders, based on standard diagnostic criteria, served as the gold standard. Accuracy measures of visuospatial tests to diagnose AD were calculated. Additionally, a new index derived from the sum of four items (Rey-Osterrieth figure copying, Copy of Drawings, Clock Drawing Test, and years of schooling) was tested (ReDCOOL).

RESULTS

Of the 342 patients analyzed, 308 were diagnosed with dementia or mild cognitive impairment, including 60 with AD. AD patients exhibited the worst performance in visuospatial tests, and the utilization of the ReDCOOL index proved to be more dependable in identifying AD compared to other tests (AUROC 0.729, 95%CI 0.659-0.799; p < 0.001).

CONCLUSION

The ReDCOOL index appears to increase confidence in the clinical diagnosis of AD compared to each of the visuospatial tests considered. Furthermore, this index is easily calculated and does not prolong the time needed for clinical evaluation, as it does not require a customized patient assessment.

[Clinical guidelines «Cognitive disorders in the elderly and senile persons»]

Clinical guidelines «Cognitive disorders in the elderly and senile persons».

Utility of the INECO Frontal Screening and the Frontal Assessment Battery in detecting executive dysfunction in early-onset cognitive impairment and dementia

OBJECTIVE

The INECO Frontal Screening (IFS) and the Frontal Assessment Battery (FAB) are executive dysfunction (ED) screening tools that can distinguish patients with neurodegenerative disorders from healthy controls and, to some extent, between dementia subtypes. This paper aims to examine the suitability of these tests in assessing early-onset cognitive impairment and dementia patients.

METHOD

In a memory clinic patient cohort (age mean = 57.4 years) with symptom onset at ≤65 years, we analyzed the IFS and the FAB results of four groups: early-onset dementia (EOD, n = 49), mild cognitive impairment due to neurological causes (MCI-n, n = 34), MCI due to other causes such as depression (MCI-o, n = 99) and subjective cognitive decline (SCD, n = 14). Data were gathered at baseline and at 6 and 12 months. We also studied the tests' accuracy in distinguishing EOD from SCD patients and ED patients from those with intact executive functioning. Correlations with neuropsychological measures were also studied.

RESULTS

The EOD group had significantly (p < .05) lower IFS and FAB total scores than the MCI-o and SCD groups. Compared with the FAB, the IFS showed more statistically significant (p < .05) differences between diagnostic groups, greater accuracy (IFS AUC = .80, FAB AUC = .75, p = .036) in detecting ED and marginally stronger correlations with neuropsychological measures. We found no statistically significant differences in the EOD group scores from baseline up to 6- or 12-months follow-up.

CONCLUSIONS

While both tests can detect EOD among memory clinic patients, the IFS may be more reliable in detecting ED than the FAB.

The Frontal Assessment Battery 20 years later: normative data for a shortened version (FAB15)

OBJECTIVE

The Frontal Assessment Battery (FAB) is a neuropsychological tool largely used to assess executive functions. Prior studies found a marked ceiling effect for the prehension behavior subtest (PBT) in healthy and clinical populations. Aims of the present study were (i) to examine the psychometric properties of the FAB without the contribution of PBT and (ii) to provide normative data for a revised version of the FAB after exclusion of PBT (FAB15).

METHODS

The normative sample included 1,187 healthy participants. PBT had near-zero variance, poor content validity, and no discrimination power. Internal consistency increased when PBT was excluded. We assessed the FAB15 factorial structure, interrater, and test-retest reliabilities. Normative data  for the FAB15 were extracted through a regression-based procedure according to sex, age, and education.

RESULTS

The principal component analysis revealed a single "executive factor" or alternatively a bifactorial solution reflecting the different degree of discriminative capability vs. difficulty of the subtests. The FAB15 demonstrated excellent interrater and test-retest reliabilities. Regression analysis showed that sex (lowly educated women < lowly educated men), higher age, and lower education affected FAB15 score. Accordingly, three grids for adjustment of raw scores (men, women, and both) were constructed. The cut-off was fixed at the non-parametric outer tolerance limit on the fifth centile (9.36, 95% CI).

CONCLUSION

The observation of a ceiling effect in healthy subjects makes PBT not suitable for inclusion in a neuropsychological battery. The FAB15 may successfully replace the conventional FAB as a more severe and valid short screening tool to assess executive functioning.

An analysis of neurocognitive dysfunction in brain tumors

BACKGROUND

Neurocognitive dysfunction is an important issue in patients with frontal lobe lesions. These patients who may be in good neurological status may succumb to neurocognitive dysfunction, affecting their daily living and hampering the quality of life. This study aims to correlate pre- and post-operative neurocognitive dysfunction in patients with frontal lobe lesions.

MATERIALS AND METHODS

A prospective analysis of 50 patients of newly-diagnosed frontal lobe tumors of any grade deemed suitable for surgical resection was carried out. All patients underwent neurocognitive testing using frontal assessment battery (FAB), mini mental state examination, and verbal learning and memory test pre- and post-operatively.

RESULTS

In this study, 22 patients had right frontal lobe lesion, whereas in 24 patients, it was located in the left frontal lobe, and 4 patients had bilateral lesions. Only 12 patients were found to be in good FAB score preoperatively, and all of them had symptom duration of less than 3 months. 1-week postsurgery, 26 patients achieved a good score, which increased to 44 at 3^rd month. Patients who had psychological dysfunction for more than 3 months had average-to-bad preoperative FAB scores, while at 3^rd month postoperatively, only six patients were in average score and none in bad score.

CONCLUSION

Frontal lobe lesion should be kept in mind in patients with neurocognitive dysfunction. FAB is a simple bedside test that should be included in routine neurological examination in daily neurosurgical practice to assess long-term functional outcome in patients with frontal lobe lesions.

Can Social Cognition Measurements Differentiate Behavioral Variant Frontotemporal Dementia from Alzheimer's Disease Regardless of Apathy?

BACKGROUND

Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) share cognitive and behavioral symptoms, such as apathy. Social cognition measurements are useful in distinguishing bvFTD from AD, but their accuracies may be affected by apathy.

OBJECTIVE

To investigate whether social cognition measurements can distinguish bvFTD from either apathetic or non-apathetic AD patients.

METHODS

Three groups of participants were enrolled in the present study: bvFTD (n = 22), AD (n = 20), and healthy controls (HC, n = 23). The AD group was divided into apathetic (n = 10) and non-apathetic (n = 10). All subjects underwent comprehensive neuropsychological examination, including the short version of the Social and Emotional Assessment (Mini-SEA), which comprises the facial emotion recognition test and the faux-pas recognition test (Faux-Pas Test). Apathy was assessed according to the Starkstein's Apathy (SA) Scale.

RESULTS

The bvFTD and AD groups did not differ on global cognitive efficiency and on executive functions. In comparison to the whole AD group, bvFTD displayed lower Faux-Pas Test and Mini-SEA scores. Both AD subgroups, apathetic or non-apathetic, exhibited similar performance on all social cognition measurements. In comparison to either apathetic AD or non-apathetic AD, bvFTD patients underperformed on the Faux-Pas Test and on the Mini-SEA. The area under the curve values for the Mini-SEA total score were 0.87 (bvFTD versus AD), 0.90 (bvFTD versus apathetic AD), and 0.83 (bvFTD versus non-apathetic AD).

CONCLUSION

Social cognition tests provide accurate distinction between bvFTD against either apathetic AD or non-apathetic AD. Social cognition measurements did not correlate with apathy severity.

Stereoscopic Depth Perception and Visuospatial Dysfunction in Alzheimer's Disease

With visuospatial dysfunction emerging as a potential marker that can detect Alzheimer's disease (AD) even in its earliest stages and with disturbance in stereopsis suspected to be the prime contributor to visuospatial deficits in AD, we assessed stereoscopic abilities of patients with AD and mild cognitive impairment (MCI). Whereas previous research assessing patients' stereoacuity has yielded mixed results, we assessed patients' capacity to process coarse disparities that can convey adequate depth information about objects in the environment. We produced two virtual cubes at two different distances from the observer by manipulating disparity type (absolute vs. relative), disparity direction (crossed vs. uncrossed) and disparity magnitude, then had participants judge the object that appeared closer to them. Two patient groups performed as well as, or even better than elderly controls, suggesting that AD patients' coarse disparity processing capacity is capable of supporting common tasks involving reaching, grasping, driving, and navigation. Results may help researchers narrow down the exact cause(s) of visuospatial deficits in AD and develop and validate measures to assess visuospatial dysfunction in clinical trials and disease diagnosis.

Cognitive and behavioural inhibition deficits in neurodegenerative dementias

Disinhibition, mainly caused by damage in frontotemporal brain regions, is one of the major causes of caregiver distress in neurodegenerative dementias. Behavioural inhibition deficits are usually described as a loss of social conduct and impulsivity, whereas cognitive inhibition deficits refer to impairments in the suppression of prepotent verbal responses and resistance to distractor interference. In this review, we aim to discuss inhibition deficits in neurodegenerative dementias through behavioural, cognitive, neuroanatomical and neurophysiological exploration. We also discuss impulsivity and compulsivity behaviours as related to disinhibition. We will therefore describe different tests available to assess both behavioural and cognitive disinhibition and summarise different manifestations of disinhibition across several neurodegenerative diseases (behavioural variant of frontotemporal dementia, Alzheimer's disease, Parkinson's disease, progressive supranuclear palsy, Huntington's disease). Finally, we will present the latest findings about structural, metabolic, functional, neurophysiological and also neuropathological correlates of inhibition impairments. We will briefly conclude by mentioning some of the latest pharmacological and non pharmacological treatment options available for disinhibition. Within this framework, we aim to highlight i) the current interests and limits of tests and questionnaires available to assess behavioural and cognitive inhibition in clinical practice and in clinical research; ii) the interpretation of impulsivity and compulsivity within the spectrum of inhibition deficits; and iii) the brain regions and networks involved in such behaviours.

Value of the Frontal Assessment Battery Tool for Assessing the Frontal Lobe Function in Stroke Patients

OBJECTIVE

To examine the correlation between the Frontal Assessment Battery (FAB) test, which is used to assess the frontal lobe function, and anatomical lesions as well as the ability of the test to detect frontal lobe dysfunction.

METHODS

Records of stroke patients undergoing a FAB test and Mini-Mental State Examination (MMSE) were retrospectively reviewed. The patients were divided into three groups according to the lesions determined by an imaging study: frontal lobe cortex lesions, frontal subcortical circuit lesions, and other lesions. The FAB scores of the three groups were compared using the Kruskal-Wallis test. The validity of the FAB test to detect frontal lobe dysfunction was assessed by a comparison with the Computerized Neuropsychological Function Test (CNT) using the Spearman correlation coefficient. The correlation coefficients between the FAB test and MMSE were analyzed further based on the MMSE cutoff score.

RESULTS

Patients with frontal cortex lesions had significantly lower total and subtest scores according to the FAB test than the other patients. The FAB test correlated better with the CNT than the MMSE, particularly in the executive function and memory domains. A high MMSE score (r=0.435) indicated a lower correlation with the FAB test score than a low MMSE score (r=0.714).

CONCLUSION

The FAB test could differentiate frontal lobe lesions from others in stroke patients and showed a good correlation with the CNT. Moreover, the FAB test can be used in patients with high MMSE scores to detect frontal lobe dysfunction and determine the treatment strategies for stroke patients.

Normative data for the Slovak version of the Frontal Assessment Battery (FAB)

The Frontal Assessment Battery (FAB) is a well-established screening measure of frontal lobe pathology. The aim of this study is the development of normative data for healthy Slovak adults. The final sample consisted of 487 healthy adults (54% of them female). The mean age in our sample was M = 55.29 (SD = 19.96). For the whole sample, the mean score on the FAB was 16.46 and the SD was 1.64. The mean score on the MMSE for the whole sample was 28.39 and the SD was 1.43. All participants underwent a complex neuropsychological examination spanning the relevant cognitive domains. FAB scores were found to be negatively associated with age (rs = -0.464, p < 0.001) and positively associated with years of education (rs = 0.199, p < 0.001). FAB scores positively correlated with the performance in MMSE (rs = 0.266, p < 0.001). Statistically significant and theoretically meaningful associations to other neuropsychological tests used in this study suggested the adequate convergent validity of the Slovak version of the FAB. The present study provided accurate normative FAB data, which can be used for clinical and research purposes.

Disinhibition in Frontotemporal Dementia and Alzheimer's Disease: A Neuropsychological and Behavioural Investigation

OBJECTIVE

Cognitive tests of inhibitory control show variable results for the differential diagnosis between behavioural variant of Frontotemporal Dementia (bvFTD) and Alzheimer's disease (AD). We compared the diagnostic accuracies of tests of inhibitory control and of a behavioural questionnaire, to distinguish bvFTD from AD.

METHODS

Three groups of participants were enrolled: 27 bvFTD patients, 25 AD patients, and 24 healthy controls. Groups were matched for gender, education, and socio-economic level. Participants underwent a comprehensive neuropsychological assessment of inhibitory control, including Hayling Test, Stroop, the Five Digits Test (FDT) and the Delay Discounting Task (DDT). Caregivers completed the Barratt Impulsiveness Scale 11th version (BIS-11).

RESULTS

bvFTD and AD groups showed no difference in the tasks of inhibitory control, while the caregiver questionnaire revealed that bvFTD patients were significantly more impulsive (BIS-11: bvFTD 76.1+9.5, AD 62.9+13, p < .001).

CONCLUSIONS

Neuropsychological tests of inhibitory control failed to distinguish bvFTD from AD. On the contrary, impulsivity caregiver-completed questionnaire provided good distinction between bvFTD and AD. These results highlight the current limits of cognitive measures of inhibitory control for the differential diagnosis between bvFTD and AD, whereas questionnaire information appears more reliable and in line with clinical diagnostics.

Phenocopy syndrome of behavioral variant frontotemporal dementia: a systematic review

Background

The phenocopy syndrome of behavioral variant of frontotemporal dementia (phFTD) refers to patients presenting with neuropsychiatric symptoms mimicking the behavioral variant frontotemporal dementia (bvFTD), but lacking frontotemporal atrophy/hypometabolism on neuroimaging and not evolving to dementia during the follow-up. It is important to recognize phFTD for clinical and research purposes.

Objective

The aim of this study was to perform a systematic review of the available literature on phFTD taking into account its clinical, cognitive, imaging, genetic, and pathological features.

Methods and results

We searched for the following terms in two electronic databases (PubMed and Scopus): “frontotemporal dementia and slowly progressive,” “frontotemporal dementia and phenocopy,” “frontotemporal dementia and non-progressive,” “frontotemporal dementia and benign progression,” and “frontotemporal dementia and benign.” We did not include review articles. Papers had to be written in English, French, Portuguese, or Spanish. Overall, 235 studies were retrieved in the initial search. A total of 31 studies composed the final selection, comprising 292 patients. Patients with phFTD are predominantly male and have no major cognitive deficits, with globally preserved executive functions and episodic memory. Some cases (n = 7) of slowly progressive FTD have been associated with C9orf72 genetic expansion. There are only four reports of phFTD neuropathological data, with two patients with no neurodegenerative findings and two with frontotemporal lobar degeneration with ubiquitin-positive inclusions.

Conclusion

The neurobiological underpinnings of phFTD remain unknown. It is controversial whether phFTD belongs to the FTD spectrum. Studies with biomarkers and pathological data are needed to solve the phFTD conundrum.

Frontal Assessment Battery in Early Cognitive Impairment: Psychometric Property and Factor Structure

BACKGROUND

The Frontal Assessment Battery (FAB) is a reliable and valid bedside tool for testing executive function in dementia. Given the increasing interest in utility of FAB as a screening tool in early cognitive impairment (ECI), there is a surprising lack of studies evaluating its psychometric property and factor structure, nor the influence of factors such as age, education and gender, in ECI.

OBJECTIVES

This study aims to investigate the psychometric properties and factor structure of FAB in older adults with ECI, as well as the influence of age, gender and education.

DESIGN, SETTING AND PARTICIPANTS

This is a retrospective, observational cross-sectional study with 300 community dwelling, predominantly Chinese older adults (14 normal, 130 mild cognitive impairment (MCI), and 156 mild dementia) who presented to Memory Clinic from January 2011 to December 2013. Measurements and Analysis: We collected data on demographic, cognitive, functional and behavioral evaluation. To examine the psychometric properties of FAB, we examined the concurrent, convergent, and discriminant validity; internal consistency by Cronbach's alpha; and factor structure by exploratory factor analysis. The influence of age, education and gender was examined using unadjusted and adjusted correlational analyses with CDR-SOB. We performed analysis for the whole group and for MCI subgroup.

RESULTS

FAB total score decreases significantly from normal to dementia group attesting to concurrent validity. It correlated significantly with digit span backwards and Chinese Mini Mental State Examination (r=0.38 and 0.47 respectively, p<0.01) and poorly with Neuropsychiatric Inventory-Questionnaire and depression (r=0.004 and -0.02 respectively), supporting its convergent and discriminant validity. Factor analysis yielded a single-factor solution for FAB with fair Internal consistency (alpha=0.610). FAB is relatively unaffected by age, gender and education level. These good psychometric properties extend to MCI, albeit with greater influence by education level. FAB items of conceptualization and mental flexibility have good discriminatory ability between MCI and normal subjects.

CONCLUSION

FAB has good concurrent, convergent and discriminant validity with fair internal consistency in ECI that is premised on a one-factor structure. It is relatively unaffected by age, gender or education. Taken together, FAB is a useful bedside screening tool for executive function in ECI.

Meta-analytic Review of Memory Impairment in Behavioral Variant Frontotemporal Dementia

OBJECTIVES

A meta-analysis of the extent, nature and pattern of memory performance in behavioral variant frontotemporal dementia (bvFTD). Multiple observational studies have challenged the relative sparing of memory in bvFTD as stated in the current diagnostic criteria.

METHODS

We performed a meta-analytic review covering the period 1967 to February 2017 of case-control studies on episodic memory in bvFTD versus control participants (16 studies, 383 patients, 603 control participants), and patients with bvFTD versus those with Alzheimer's disease (AD) (20 studies, 452 bvFTD, 874 AD). Differences between both verbal and non-verbal working memory, episodic memory learning and recall, and recognition memory were examined. Data were extracted from the papers and combined into a common metric measure of effect, Hedges' d.

RESULTS

Patients with bvFTD show large deficits in memory performance compared to controls (Hedges' d -1.10; 95% confidence interval [CI] [-1.23, -0.95]), but perform significantly better than patients with AD (Hedges' d 0.85; 95% CI [0.69, 1.03]). Learning and recall tests differentiate best between patients with bvFTD and AD (p<.01). There is 37-62% overlap in test scores between the two groups.

CONCLUSIONS

This study points to memory disorders in patients with bvFTD, with performance at an intermediate level between controls and patients with AD. This indicates that, instead of being an exclusion criterion for bvFTD diagnosis, memory deficits should be regarded as a potential integral part of the clinical spectrum. (JINS, 2018, 24, 593-605).

A Longitudinal Study on Resting State Functional Connectivity in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease

BACKGROUND/OBJECTIVE

Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are the most common types of early-onset dementia. We applied longitudinal resting state functional magnetic resonance imaging (fMRI) to delineate functional brain connections relevant for disease progression and diagnostic accuracy.

METHODS

We used two-center resting state fMRI data of 20 AD patients (65.1±8.0 years), 12 bvFTD patients (64.7±5.4 years), and 22 control subjects (63.8±5.0 years) at baseline and 1.8-year follow-up. We used whole-network and voxel-based network-to-region analyses to study group differences in functional connectivity at baseline and follow-up, and longitudinal changes in connectivity within and between groups.

RESULTS

At baseline, connectivity between paracingulate gyrus and executive control network, between cuneal cortex and medial visual network, and between paracingulate gyrus and salience network was higher in AD compared with controls. These differences were also present after 1.8 years. At follow-up, connectivity between angular gyrus and right frontoparietal network, and between paracingulate gyrus and default mode network was lower in bvFTD compared with controls, and lower compared with AD between anterior cingulate gyrus and executive control network, and between lateral occipital cortex and medial visual network. Over time, connectivity decreased in AD between precuneus and right frontoparietal network and in bvFTD between inferior frontal gyrus and left frontoparietal network. Longitudinal changes in connectivity between supramarginal gyrus and right frontoparietal network differ between both patient groups and controls.

CONCLUSION

We found disease-specific brain regions with longitudinal connectivity changes. This suggests the potential of longitudinal resting state fMRI to delineate regions relevant for disease progression and for diagnostic accuracy, although no group differences in longitudinal changes in the direct comparison of AD and bvFTD were found.

The frontal assessment battery in clinical practice: a systematic review

BACKGROUND

The frontal assessment battery (FAB) is a brief tool designed to evaluate executive function. Some studies have particularly focused on assessing its applicability addressing two issues: first, on detecting the brain regions responsible for the FAB performance, and second, on determining its capability for differential diagnosis. Our aim was to summarize and analyze critically the studies that assessed the neuroanatomical correspondence and the differential diagnostic value of the FAB in several study populations suffering from different pathologies.

METHODS

We completed a literature search in MEDLINE (via PubMed) database by using the term "frontal assessment battery" and the combination of this term with "applicability" or "use" or "usefulness". The search was limited to articles in English or Spanish languages, published between 1 September 2000 and 30 September 2016, human studies, and journal articles.

RESULTS

A total of 32 studies met inclusion criteria. Seventeen studies were aimed at identifying the brain regions or the neural substrates involved in executive functions measured by the FAB and 15 studies at verifying that the FAB was an appropriate tool for the differential diagnosis in neurological diseases.

CONCLUSION

Our study showed that the FAB may be an adequate assessment tool for executive function and may provide useful information for differential diagnosis in several diseases. Given that the FAB takes short time and is easy to administer, its usage may be of great interest as part of a full neuropsychological assessment in clinical settings. Copyright © 2017 John Wiley & Sons, Ltd.

Frontal Assessment Battery as a Useful Tool to Differentiate Mild Cognitive Impairment due to Subcortical Ischemic Vascular Disease from Alzheimer Disease

BACKGROUND

Prominent executive dysfunction can differentiate vascular dementia from Alzheimer disease (AD). However, it is unclear whether the Frontal Assessment Battery (FAB) screening tool can differentiate subcortical ischemic vascular disease (SIVD) from AD at the pre-dementia stage. In addition, the neural correlates of FAB performance have yet to be clarified.

METHODS

Patients with mild cognitive impairment (MCI) due to SIVD (MCI-V), MCI due to AD (MCI-A), and demographically matched controls completed the Mini-Mental State Examination, Taiwanese FAB (TFAB), Category Fluency, and Chinese Version of the Verbal Learning Test, and underwent magnetic resonance imaging. White matter hyperintensities were rated according to the Scheltens scale.

RESULTS

TFAB total scale and its Orthographical Fluency subtest were the only measures that could differentiate MCI-V from MCI-A. Discriminative analysis showed that Orthographical Fluency scores successfully identified 73.2% of the cases with MCI-V, with 85.0% sensitivity. Orthographical Fluency scores were specifically associated with lesion load within frontal periventricular, frontal deep white matter, and basal ganglia regions.

CONCLUSION

The TFAB, and especially its 1-min Orthographical Fluency subtest, is a useful screening procedure to differentiate MCI due to SIVD from MCI due to AD. The discriminative ability is probably due to frontosubcortical white matter pathologies disproportionately involved in the two disease entities.

Assessing Executive Dysfunction in Neurodegenerative Disorders: A Critical Review of Brief Neuropsychological Tools

Executive function (EF) has been defined as a multifaceted construct that involves a variety of high-level cognitive abilities such as planning, working memory, mental flexibility, and inhibition. Being able to identify deficits in EF is important for the diagnosis and monitoring of several neurodegenerative disorders, and thus their assessment is a topic of much debate. In particular, there has been a growing interest in the development of neuropsychological screening tools that can potentially provide a reliable quick measure of EF. In this review, we critically discuss the four screening tools of EF currently available in the literature: Executive Interview-25 (EXIT 25), Frontal Assessment Battery (FAB), INECO Frontal Screening (IFS), and FRONTIER Executive Screen (FES). We first describe their features, and then evaluate their psychometric properties, the existing evidence on their neural correlates, and the empirical work that has been conducted in clinical populations. We conclude that the four screening tools generally present appropriate psychometric properties, and are sensitive to impairments in EF in several neurodegenerative conditions. However, more research will be needed mostly with respect to normative data and neural correlates, and to determine the extent to which these tools add specific information to the one provided by global cognition screening tests. More research directly comparing the available tools with each other will also be important to establish in which conditions each of them can be most useful.

Can visuospatial measures improve the diagnosis of Alzheimer's disease?

Introduction

Overlapping and evolving symptoms lead to ambiguity in the diagnosis of dementia. Visuospatial function relies on parietal lobe function, which may be affected in the early stages of Alzheimer's disease (AD). This review evaluates visuospatial dysfunction in patients with AD, frontotemporal dementia, dementia with Lewy bodies, and vascular dementia to determine the diagnostic and prognostic potential of visuospatial tasks in AD.

Methods

A systematic search of studies (1960–2016) investigating visuospatial dysfunction in dementia was conducted.

Results

Tests measuring construction, specifically Block Design and Clock Drawing Test, and visual memory, specifically Rey-Osterrieth Complex Figure recall and topographical tasks, show the greatest diagnostic potential in dementia. The Benton visual retention, Doors and People, and topographical memory tests show potential as prognostic markers.

Discussion

Tests of visuospatial function demonstrate significant diagnostic and prognostic potential in dementia. Further studies with larger samples of pathologically confirmed cases are required to verify clinical utility.

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Memory deficits have been demonstrated in Alzheimer's and non-Alzheimer's dementias.

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Parietal lobes are uniquely affected in the early stages of Alzheimer's disease.

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Visuospatial tasks demonstrate significant diagnostic and prognostic potential.

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Computerized test protocols have been developed to test aspects of visuospatial function and memory.

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Novel topographical memory tasks demonstrated the greatest prognostic potential.

The need for harmonisation and innovation of neuropsychological assessment in neurodegenerative dementias in Europe: consensus document of the Joint Program for Neurodegenerative Diseases Working Group

Cognitive, behavioural, and functional assessment is crucial in longitudinal studies of neurodegenerative dementias (NDD). Central issues, such as the definition of the study population (asymptomatic, at risk, or individuals with dementia), the detection of change/decline, and the assessment of relevant outcomes depend on quantitative measures of cognitive, behavioural, and functional status.

Currently, we are far from having available reliable protocols and tools for the assessment of dementias in Europe. The main problems are the heterogeneity of the tools used across different European countries, the lack of standardisation of administration and scoring methods across centres, and the limited information available about the psychometric properties of many tests currently in widespread use. This situation makes it hard to compare results across studies carried out in different centres, thus hampering research progress, in particular towards the contribution to a “big data” common data set.

We present here the results of a project funded by the Joint Program for Neurodegenerative Diseases (JPND) and by the Italian Ministry of Health. The project aimed at providing a consensus framework for the harmonisation of assessment tools to be applied to research in neurodegenerative disorders affecting cognition across Europe. A panel of European experts reviewed the current methods of neuropsychological assessment, identified pending issues, and made recommendations for the harmonisation of neuropsychological assessment of neurodegenerative dementias in Europe.

A consensus was achieved on the general recommendations to be followed in developing procedures and tools for neuropsychological assessment, with the aim of harmonising tools and procedures to achieve more reliable data on the cognitive-behavioural examination. The results of this study should be considered as a first step to enhancing a common view and practise on NDD assessment across European countries.

Gray matter network differences between behavioral variant frontotemporal dementia and Alzheimer's disease

We set out to study whether single-subject gray matter (GM) networks show disturbances that are specific for Alzheimer's disease (AD; n = 90) or behavioral variant frontotemporal dementia (bvFTD; n = 59), and whether such disturbances would be related to cognitive deficits measured with mini-mental state examination and a neuropsychological battery, using subjective cognitive decline subjects as reference. AD and bvFTD patients had a lower degree, connectivity density, clustering, path length, betweenness centrality, and small world values compared with subjective cognitive decline. AD patients had a lower connectivity density than bvFTD patients (F = 5.79, p = 0.02; mean ± standard deviation bvFTD 16.10 ± 1.19%; mean ± standard deviation AD 15.64 ± 1.02%). Lasso logistic regression showed that connectivity differences between bvFTD and AD were specific to 23 anatomical areas, in terms of local GM volume, degree, and clustering. Lower clustering values and lower degree values were specifically associated with worse mini-mental state examination scores and lower performance on the neuropsychological tests. GM showed disease-specific alterations, when comparing bvFTD with AD patients, and these alterations were associated with cognitive deficits.

Evaluation of the INECO Frontal Screening and the Frontal Assessment Battery in Peruvian patients with Alzheimer's disease and behavioral variant Frontotemporal dementia

Background

The physicians often confuse the early symptoms of Frontotemporal dementia (FTD) with Alzheimer dementia (AD), leading to misdiagnosis. There are some cognitive tests to discriminate between AD and behavioral variant FTD (bvFTD), and the INECO Frontal Screening (IFS) is a promising test for this purpose.

Objective

To assess the performance of the IFS to differentiate patients with AD from patients with bvFTD, compared with the Frontal Assessment Battery (FAB).

Methods

A prospective study with 117 patients of our cognitive unit (35 case-patients with AD, 34 case-patients with bvFTD, and 48 control subjects). They were submitted to the following successive phases of evaluation: 1) screening; 2) dementia diagnosis; and 3) dementia sub-type diagnosis. The IFS and FAB were blind and independently applied by one neurologist to all the participants to end of phase 1 (screening), before to the definitive diagnosis establishment.

Results

bvFTD showed a lower performance than AD patients on the IFS total score (F(1, 66) = 70.10, p < 0.01) and FAB total score (F(1, 66) = 17.91, p < 0.01). The IFS and FAB showed a sensitivity of 94.12% (95%CI = 80.3–99.2) and 82.3% (95%CI = 65.4–93.2), and a specificity of 94.2% (95%CI = 80.8–99.3) and 48.5% (95%CI = 31.3, 66.1), respectively. The IFS showed significantly superior discriminatory accuracy than the FAB (AuC_IFS = 0.98; AuC_FAB = 0.73, p < 0.00001).

Conclusion

The IFS is useful for discriminating between AD and bvFTD patients. The performance of the IFS to differentiate patients with AD from patients with bvFTD is greater than FAB.

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Early symptoms of FTD are confused with AD.

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In low-income countries is necessary to dispose of validated brief cognitive tests for discriminating between dementia of healthy individuals.

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IFS and FAB are useful cognitive tests for discriminating dementia, but IFS has a good performance to discriminate between AD and FTD.

The Frontal Assessment Battery: Normative Performance in a Large Sample of Older Community-Dwelling Hospital Outpatient or General Practitioner Attenders

BACKGROUND

The Frontal Assessment Battery (FAB) is a short battery designed to assess frontal executive functioning, but data for interpretation of performance are limited.

OBJECTIVES

The Trinity, Ulster, Department of Agriculture (TUDA) study provided the opportunity to derive performance data from a large sample of community-dwelling hospital outpatient or general practitioner (GP) attenders.

METHODS

Normative analysis based on 2508 TUDA participants meeting these criteria: Mini-Mental State Examination (MMSE) >26/30, not depressed (Center for Epidemiologic Studies Depression <16) or anxious (Hospital Anxiety and Depression Scale <8), no history of stroke, or transient ischemic attack. Correlation and regression analyses were used to evaluate the effects of age, education, gender, and general cognition (MMSE). Norms for FAB were created stratified by age and education, using overlapping midpoint ranges of 10 years with a 3-year interval from age 60 to 97.

RESULTS

Age and education accounted for 9.6% of variance in FAB score ( r² = .096) with no significant effect of gender. The FAB and MMSE were modestly correlated ( r = .29, P < .01) with MMSE increasing the model's total explained variance in FAB score from 9.6% to 14%.

CONCLUSION

This is the largest study to date to create normative data for the FAB. Age and education had the most significant impact on FAB performance, which was largely independent of global cognition (MMSE). These data may be of benefit in interpreting FAB performance in individuals with similar demographic/health status characteristics in hospital outpatient or GP settings.

FRONTIER Executive Screen: a brief executive battery to differentiate frontotemporal dementia and Alzheimer's disease

BACKGROUND AND OBJECTIVE

Executive dysfunctions are a key clinical feature of behavioural-variant frontotemporal dementia (bvFTD). Such deficits are also found in Alzheimer's disease (AD), making the differentiation between these two diseases difficult at times, particularly in the absence of extensive cognitive assessments. To address this issue, we developed the FRONTIER Executive Screen (FES), which combines three abbreviated measures of verbal fluency, inhibitory control and working memory.

METHODS

We administered the FES to 28 patients with dementia (14 bvFTD, 14 AD) matched for disease severity and 33 age-matched and education-matched healthy controls. We also administered traditional tests of executive function to establish the concurrent validity of the FES.

RESULTS

Both patient groups obtained lower FES scores (total and subscores) compared to controls. Correct classification into patient or control groups was reached in over 90% of study participants based on the FES total score. Only two patients with bvFTD obtained FES scores within 2 SDs of the control group. Receiver operating characteristic analyses on the patient groups showed that a cut-off FES total score of 7/15 achieved 71% sensitivity and 73% specificity for a diagnosis of bvFTD. In addition, the FES showed high correlations with traditional measures of executive function.

CONCLUSIONS

The FES is a brief (5-10 min) bedside screening measure which is simple to administer and score, and demonstrates good discriminative validity to differentiate bvFTD from AD. It is a useful addendum to general cognitive screening measures and can help with the differential diagnosis of dementia.

Alzheimer Disease and Behavioral Variant Frontotemporal Dementia: Automatic Classification Based on Cortical Atrophy for Single-Subject Diagnosis

Purpose To investigate the diagnostic accuracy of an image-based classifier to distinguish between Alzheimer disease (AD) and behavioral variant frontotemporal dementia (bvFTD) in individual patients by using gray matter (GM) density maps computed from standard T1-weighted structural images obtained with multiple imagers and with independent training and prediction data. Materials and Methods The local institutional review board approved the study. Eighty-four patients with AD, 51 patients with bvFTD, and 94 control subjects were divided into independent training (n = 115) and prediction (n = 114) sets with identical diagnosis and imager type distributions. Training of a support vector machine (SVM) classifier used diagnostic status and GM density maps and produced voxelwise discrimination maps. Discriminant function analysis was used to estimate suitability of the extracted weights for single-subject classification in the prediction set. Receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) were calculated for image-based classifiers and neuropsychological z scores. Results Training accuracy of the SVM was 85% for patients with AD versus control subjects, 72% for patients with bvFTD versus control subjects, and 79% for patients with AD versus patients with bvFTD (P ≤ .029). Single-subject diagnosis in the prediction set when using the discrimination maps yielded accuracies of 88% for patients with AD versus control subjects, 85% for patients with bvFTD versus control subjects, and 82% for patients with AD versus patients with bvFTD, with a good to excellent AUC (range, 0.81-0.95; P ≤ .001). Machine learning-based categorization of AD versus bvFTD based on GM density maps outperforms classification based on neuropsychological test results. Conclusion The SVM can be used in single-subject discrimination and can help the clinician arrive at a diagnosis. The SVM can be used to distinguish disease-specific GM patterns in patients with AD and those with bvFTD as compared with normal aging by using common T1-weighted structural MR imaging. (©) RSNA, 2015.

Resting state functional connectivity differences between behavioral variant frontotemporal dementia and Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are the most common types of early-onset dementia. Early differentiation between both types of dementia may be challenging due to heterogeneity and overlap of symptoms. Here, we apply resting state functional magnetic resonance imaging (fMRI) to study functional brain connectivity differences between AD and bvFTD.

METHODS

We used resting state fMRI data of 31 AD patients, 25 bvFTD patients, and 29 controls from two centers specialized in dementia. We studied functional connectivity throughout the entire brain, applying two different analysis techniques, studying network-to-region and region-to-region connectivity. A general linear model approach was used to study group differences, while controlling for physiological noise, age, gender, study center, and regional gray matter volume.

RESULTS

Given gray matter differences, we observed decreased network-to-region connectivity in bvFTD between (a) lateral visual cortical network and lateral occipital and cuneal cortex, and (b) auditory system network and angular gyrus. In AD, we found decreased network-to-region connectivity between the dorsal visual stream network and lateral occipital and parietal opercular cortex. Region-to-region connectivity was decreased in bvFTD between superior temporal gyrus and cuneal, supracalcarine, intracalcarine cortex, and lingual gyrus.

CONCLUSION

We showed that the pathophysiology of functional brain connectivity is different between AD and bvFTD. Our findings support the hypothesis that resting state fMRI shows disease-specific functional connectivity differences and is useful to elucidate the pathophysiology of AD and bvFTD. However, the group differences in functional connectivity are less abundant than has been shown in previous studies.

Cognitive function in survivors of out-of-hospital cardiac arrest after target temperature management at 33°C versus 36°C

BACKGROUND

Target temperature management is recommended as a neuroprotective strategy after out-of-hospital cardiac arrest. Potential effects of different target temperatures on cognitive impairment commonly described in survivors have not been investigated sufficiently. The primary aim of this study was to evaluate whether a target temperature of 33°C compared with 36°C was favorable for cognitive function; the secondary aim was to describe cognitive impairment in cardiac arrest survivors in general.

METHODS AND RESULTS

Study sites included 652 cardiac arrest survivors originally randomized and stratified for site to temperature control at 33°C or 36°C within the Target Temperature Management trial. Survival until 180 days after the arrest was 52% (33°C, n=178/328; 36°C, n=164/324). Survivors were invited to a face-to-face follow-up, and 287 cardiac arrest survivors (33°C, n=148/36°C, n=139) were assessed with tests for memory (Rivermead Behavioural Memory Test), executive functions (Frontal Assessment Battery), and attention/mental speed (Symbol Digit Modalities Test). A control group of 119 matched patients hospitalized for acute ST-segment-elevation myocardial infarction without cardiac arrest performed the same assessments. Half of the cardiac arrest survivors had cognitive impairment, which was mostly mild. Cognitive outcome did not differ (P>0.30) between the 2 temperature groups (33°C/36°C). Compared with control subjects with ST-segment-elevation myocardial infarction, attention/mental speed was more affected among cardiac arrest patients, but results for memory and executive functioning were similar.

CONCLUSIONS

Cognitive function was comparable in survivors of out-of-hospital cardiac arrest when a temperature of 33°C and 36°C was targeted. Cognitive impairment detected in cardiac arrest survivors was also common in matched control subjects with ST-segment-elevation myocardial infarction not having had a cardiac arrest.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01946932.

Differential diagnosis of degenerative dementias using basic neuropsychological tests: multivariable logistic regression analysis of 301 patients

BACKGROUND

The validity of neuropsychological tests for the differential diagnosis of degenerative dementias may depend on the clinical context. We constructed a series of logistic models taking into account this factor.

METHODS

We retrospectively analyzed the demographic and neuropsychological data of 301 patients with probable Alzheimer's disease (AD), frontotemporal degeneration (FTLD), or dementia with Lewy bodies (DLB). Nine models were constructed taking into account the diagnostic question (eg, AD vs DLB) and subpopulation (incident vs prevalent).

RESULTS

The AD versus DLB model for all patients, including memory recovery and phonological fluency, was highly accurate (area under the curve = 0.919, sensitivity = 90%, and specificity = 80%). The results were comparable in incident and prevalent cases. The FTLD versus AD and DLB versus FTLD models were both inaccurate.

CONCLUSION

The models constructed from basic neuropsychological variables allowed an accurate differential diagnosis of AD versus DLB but not of FTLD versus AD or DLB.

Re-evaluation of clinical dementia diagnoses with pittsburgh compound B positron emission tomography

Objectives

There is an overlap regarding Pittsburgh compound B (PIB) retention in patients clinically diagnosed as Alzheimer's disease (AD) and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [¹⁸F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET).

Methods

Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting.

Results

The PIB-positive patients (7 out of 18) had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18) during follow-up.

Conclusions

The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.

Can theory of mind deficits be measured reliably in people with mild and moderate Alzheimer's dementia?

BACKGROUND

Patients suffering from Alzheimer's dementia develop difficulties in social functioning. This has led to an interest in the study of "theory of mind" in this population. However, difficulty has arisen because the associated cognitive demands of traditional short story theory of mind assessments result in failure per se in this population, making it challenging to test pure theory of mind ability.

METHODS

Simplified, traditional 1st and 2nd order theory of mind short story tasks and a battery of alternative theory of mind cartoon jokes and control slapstick cartoon jokes, without memory components, were administered to 16 participants with mild-moderate Alzheimer's dementia, and 11 age-matched healthy controls.

RESULTS

No significant differences were detected between participants with Alzheimer's dementia and controls on the 1st or 2nd order traditional short story theory of mind tasks (p = 0.155 and p = 0.154 respectively). However, in the cartoon joke tasks there were significant differences in performance between the Alzheimer participants and the control group, this was evident for both theory of mind cartoons and the control 'slapstick' jokes.

CONCLUSION

It remains very difficult to assess theory of mind as an isolated phenomenon in populations with global cognitive impairment, such as Alzheimer's dementia, as the tasks used to assess this cognition invariably depend on other cognitive functions. Although a limitation of this study is the small sample size, the results suggest that there is no measurable specific theory of mind deficit in people with Alzheimer's dementia, and that the use of theory of mind representational models to measure social cognitive ability may not be appropriate in this population.

Performance on the Frontal Assessment Battery is sensitive to frontal lobe damage in stroke patients

Background

The Frontal Assessment Battery (FAB) is a brief battery of six neuropsychological tasks designed to assess frontal lobe function at bedside [Neurology 55:1621-1626, 2000]. The six FAB tasks explore cognitive and behavioral domains that are thought to be under the control of the frontal lobes, most notably conceptualization and abstract reasoning, lexical verbal fluency and mental flexibility, motor programming and executive control of action, self-regulation and resistance to interference, inhibitory control, and environmental autonomy.

Methods

We examined the sensitivity of performance on the FAB to frontal lobe damage in right-hemisphere-damaged first-ever stroke patients based on voxel-based lesion-behavior mapping.

Results

Voxel-based lesion-behavior mapping of FAB performance revealed that the integrity of the right anterior insula (BA13) is crucial for the FAB global composite score, for the FAB conceptualization score, as well as for the FAB inhibitory control score. Furthermore, the FAB conceptualization and mental flexibility scores were sensitive to damage of the right middle frontal gyrus (MFG; BA9). Finally, the FAB inhibitory control score was sensitive to damage of the right inferior frontal gyrus (IFG; BA44/45).

Conclusions

These findings indicate that several FAB scores (including composite and item scores) provide valid measures of right hemispheric lateral frontal lobe dysfunction, specifically of focal lesions near the anterior insula, in the MFG and in the IFG.

FAB-D: German version of the Frontal Assessment Battery

Executive dysfunction (ED) is a frequent consequence of neurological disorders, such as stroke, trauma or dementia, but also appears in normal aging. We developed a German version of the Frontal Assessment Battery (FAB-D), a short test which has previously been developed (Dubois et al., Neurology 55:1621-1626, 2000) to detect ED during bedside screening. A sample of 401 cognitively intact subjects aged 50-95 was tested with the FAB-D and several neuropsychological tests tapping executive functions, memory and calculation abilities. Aim of the study was to receive normative data for different age and educational groups, and to learn which tests predict performance on the FAB-D. We found clear effects of age and education; furthermore, FAB-D performance was predicted by other tests of executive functioning, but also by calculation and memory abilities. The present study reports data of healthy individuals and may be useful for comparing patients' performance with a normative sample.

Presenting neuropsychological testing profile of autopsy-confirmed frontotemporal lobar degeneration

AIMS

We aimed to investigate how neuropsychological test measures at presentation might differentiate frontotemporal lobar degeneration (FTLD) from Alzheimer's disease (AD).

METHODS

We compared autopsy-confirmed FTLD and definite AD with Clinical Dementia Rating ≤1. Factor scores and t values of each neuropsychological test measure were compared between FTLD and AD patients. Logistic regression analyses were applied to identify independent predictors within test measures for the differentiation of FTLD from AD.

RESULTS

Factor analyses showed that the memory domain was more severely impaired in AD than in FTLD, whereas the language and attention domains were more severely impaired in FTLD than in AD. Multiple logistic regression analysis showed that Letter Fluency, Boston Naming Test and delayed memory recall remained independent predictors of FTLD compared to AD. However, test measures did not discriminate between FTLD-tau and FTLD-ubiquitin.

CONCLUSION

We confirm that memory and language function tests discriminate between FTLD and AD.

The frontal assessment battery in the differential diagnosis of dementia

AIM

The Frontal Assessment Battery (FAB) has been used in different clinical settings as a valuable quick bedside test for executive dysfunction. The aim of the study was to evaluate clinical utility of the FAB for differential diagnosis of Alzheimer disease (AD), subcortical vascular cognitive impairment (scVCI), and frontotemporal lobar degeneration (FTLD).

METHODS

Scores of the total FAB test and subtests were compared between consecutive series of 37 patients with AD, 31 patients with scVCI, 13 patients with FTLD, and 29 cognitively healthy individuals.

RESULTS

There was no statistically significant difference in the total FAB scores among the groups of patients with dementia. When comparing subtest scores, patients with FTLD had significantly lower scores on the lexical fluency subtest compared to the patients with AD (P<.001) or scVCI (P<.001); patients with scVCI had significantly lower scores on the motor series subtest compared to patients with FTLD (P=.02) and AD (P=.035) and on conflicting instructions subtest compared to patients with AD (P=.033).

CONCLUSION

Some FAB subtests might enhance diagnostic accuracy taking into account clinical history and other tests of executive function.

Frontal assessment battery and brain perfusion imaging in Alzheimer's disease

BACKGROUND

The frontal assessment battery (FAB) is reported to be a useful tool for assessing frontal dysfunction. However, the neural substrates involved in patients with Alzheimer's disease (AD) remain to be elucidated. The aim of the present study was to identify the regional perfusion patterns of the brain associated with performance scores on the FAB of patients with AD using brain perfusion assessed by single photon emission computed tomography (SPECT).

METHODS

Twenty-four AD patients with high scores and 24 age- and sex-matched AD patients with low scores on the FAB were selected from 470 consecutive Japanese patients of the Memory Clinic of Okayama University Hospital. All 48 participants underwent brain SPECT with 99mTc-ethylcysteinate dimer, and the SPECT images were analyzed by statistical parametric mapping.

RESULTS

No significant differences were found between high and low FAB scoring groups with respect to Addenbrooke's Cognitive Examination scores, Mini-Mental State Examination scores, or the depression score of the Neuropsychiatric Inventory subscale. Compared with patients with high scores on the FAB, AD patients with low scores showed significant hypoperfusion in the left middle frontal gyrus (MFG) and the right superior frontal gyrus (SFG) extending to the left SFG.

CONCLUSION

Our results suggest that functional activity of the SFG and MFG is closely related to the FAB score. The FAB might be a promising strategy to detect early stages of AD with low SFG and MFG function.

The frontal assessment battery as a tool for evaluation of frontal lobe dysfunction in patients with Parkinson disease

BACKGROUND

Frontal-type cognitive deficits are common in patients with Parkinson disease (PD). The Frontal Assessment Battery (FAB) was developed to assess frontal lobe functions. However, many studies found that it also correlated with a variety of other general neuropsychological tests.

OBJECTIVES

To evaluate whether the FAB has an added value over the Mini-Mental State Examination (MMSE) and other bedside neuropsychological tests in reflecting cognitive deficits in patients with PD.

METHODS

Seventy-two consecutive patients with PD underwent cognitive assessment including the FAB, the MMSE, and a variety of other neuropsychological tests. Correlations were examined using the Spearman's r.

RESULTS

Highly significant correlations were found between the total FAB score and tests of attention, executive functions, and memory. To evaluate the contribution of the FAB beyond that of the MMSE, partial correlation was used. Analyses revealed that the FAB still correlated with most of the tests. Dividing the patients according to the median MMSE score revealed that the high correlation between the FAB and the MMSE was preserved in the low MMSE group, while in the high MMSE group the correlation was relatively low. In the high MMSE group, the FAB correlated with 11 tests compared to the MMSE that correlated with one (P < .001), while in the low MMSE group the number of correlations was 13 versus 7, respectively (P = .05).

CONCLUSIONS

In our sample of patients with PD, the FAB correlated with dysfunction in a variety of cognitive domains including attention, memory, and executive functions. The FAB has an added value over the MMSE, particularly among nondemented patients, an advantage that can be used in clinical practice.

Comparing the clinical usefulness of the Institute of Cognitive Neurology (INECO) Frontal Screening (IFS) and the Frontal Assessment Battery (FAB) in frontotemporal dementia

We compared the utility of two executive-function brief screening tools, the Institute of Cognitive Neurology (INECO) Frontal Screening (IFS) and the Frontal Assessment Battery (FAB), in their ability to detect executive dysfunction in a group of behavioral variant frontotemporal dementia (bv-FTD, n = 25) and Alzheimer's disease (AD, n = 25) patients in the early stages of their disease and in comparison to a group of age-, gender-, and education-matched controls (n = 26). Relative to the FAB, the IFS showed (a) better capability to differentiate between types of dementia; (b) higher sensitivity and specificity for the detection of executive dysfunction; (c) stronger correlations with standard executive tasks. We conclude that while both tools are brief and specific for the detection of early executive dysfunction in dementia, the IFS is more sensitive and specific in differentiating bvFTD from AD, and its use in everyday clinical practice can contribute to the differential diagnosis between types of dementia.

Relation between frontal lobe symptoms and dementia severity within and across diagnostic dementia categories

BACKGROUND

To study frontal lobe symptoms in relation to dementia severity within and across diagnostic dementia categories, a cross-sectional analysis of behavioural data was performed.

METHODS

Patients with probable Alzheimer's disease (AD) (n = 456), frontotemporal dementia (FTD) (n = 55) and dementia with Lewy bodies (DLB) (n = 48) were included. Dementia severity and frontal lobe symptoms were assessed by means of the global deterioration scale and the Middelheim frontality score (MFS).

RESULTS

In FTD, no difference in MFS total scores between patients belonging to the mild and severe dementia stages was found (p = 0.828). In AD and DLB groups, significantly higher MFS total scores were found in severe dementia stages compared to mild dementia stages (p < 0.001). Comparing MFS total scores between FTD and AD patients, significantly higher scores were achieved in FTD patients, irrespective of dementia severity (p < 0.001).

CONCLUSIONS

In FTD patients, frontal lobe symptoms were severe in the mild, moderate and severe dementia stages although the nature of frontal lobe symptoms depended on disease severity. AD and DLB patients displayed more frontal lobe symptoms in the advanced disease stages as compared to disease onset, suggesting gradual frontal lobe involvement as the disease progresses. The nature of frontal lobe symptoms related to dementia severity differed between AD, DLB and FTD patients, suggesting different patterns of frontal lobe involvement. Last but not the least, these data point to the potential diagnostic value of behavioural observation of frontal lobe symptoms for (differential) dementia diagnosis, especially at the earliest disease stages. These findings await confirmation through a prospective, longitudinal study.

INECO Frontal Screening (IFS): a brief, sensitive, and specific tool to assess executive functions in dementia

Although several brief sensitive screening tools are available to detect cognitive dysfunction, few have been developed to quickly assess executive functioning (EF) per se. We designed a new brief tool to evaluate EF in neurodegenerative diseases. Patients with an established diagnosis of behavioral variant frontotemporal dementia (bvFTD; n = 22), Alzheimer disease (AD; n = 25), and controls (n = 26) were assessed with a cognitive screening test, the INECO Frontal Screening (IFS), and EF tests. Clinical Dementia Rating Scale (CDR) scores were obtained for all patients. Internal consistency of the IFS was very good (Cronbach's alpha = .80). IFS total (out of 30 points) was 27.4 (SD = 1.6) for controls, 15.6 (SD = 4.2) for bvFTD, and 20.1 (SD = 4.7) for AD. Using a cutoff of 25 points, sensitivity of the IFS was 96.2%, and specificity 91.5% in differentiating controls from patients with dementia. The IFS correlated significantly with the CDR and executive tasks. The IFS total discriminated controls from demented patients, and bvFTD from AD. IFS is a brief, sensitive, and specific tool for the detection of executive dysfunction associated with neurodegenerative diseases. The IFS may be helpful in the differential diagnosis of FTD and AD.

Frontal-executive versus posterior-perceptual mental status deficits in early-onset dementias

BACKGROUND

Compared to late-onset dementias, early-onset dementias (EODs) may have greater focal cognitive involvement with differences in frontal-executive compared to posterior-perceptual deficits.

OBJECTIVE

This study evaluated whether mental status screening based on this frontal-posterior axis can distinguish EODs.

METHODS

Twenty-three patients each with early-onset Alzheimer's disease (eAD), frontotemporal dementia (FTD), or subcortical ischemic vascular disease (SIVD), and 20 normal controls underwent the Frontal Assessment Battery (FAB) and the Perceptual Assessment Battery (PAB).

RESULTS

Compared to controls, SIVD and FTD groups were impaired on the FAB whereas eAD and SIVD groups were impaired on the PAB. The FAB/PAB ratio further differentiated the groups (F(3,85) = 26.49, P < .001). For sensitivities and specificities of 93%, a cut-off score of 1.25 on the FAB/PAB distinguished eAD, and a cut-off of 0.83 distinguishing FTD.

CONCLUSION

Although preliminary, this study indicates that mental status screening based on frontal versus posterior cortical functions may help clinicians diagnose EODs.

A short neuropsychologic and cognitive evaluation of frontotemporal dementia

OBJECTIVE

To elaborate a brief but efficient neuropsychological assessment of frontotemporal dementia (FTD), selecting the most specific and sensitive cognitive and behavioural items for distinguish between AD and FTD in the earlier dementia stages.

METHODS

Retrospective study with three groups, 35 patients with FTD, 46 with AD and 36 normal subjects, were administered the MMSE, FAB, Tower of London and Stoop's test along with a 98 items behavioural and cognitive questionnaire. The most sensitive items were selected and validated internally for diagnosis by lineal discriminant analysis.

RESULTS

From the 98 items in the questionnaire, 29 showed significant discriminatory power. Non-cognitive symptoms with higher odd-ratio for FTD compared to AD were impairment in social behaviour (disinhibition, aggressiveness), loss of insight and inappropriate acts. Language disorders, such as echolalia, verbal apraxia or aggramatism, dominate in the cognitive profile of FTD. FAB was confirmed as the best cognitive instrument to differentiate FTD and AD. A linear discriminant function with the combination of the FAB score and the items from our questionnaire with higher OR for FTD accurately classified 97% of individuals.

CONCLUSIONS

The neuropsychological tests allow the differentiation between FTD and AD. The combination of FAB test with the assessment of key behavioural and cognitive symptoms appears helpful in this distinction.

Association between apathy/depression and executive function in patients with Alzheimer's disease

BACKGROUND

Apathy and depression may be strongly associated with executive dysfunction in Alzheimer's disease (AD). The Frontal Assessment Battery (FAB) is an instrument for assessing executive function. The dual task paradigm is also useful for assessing divided attention. However, the association between apathy/depression and these tasks is unclear.

METHODS

Both the FAB and the dual task were used to evaluate AD patients. A two-way analysis of variance was then conducted between the FAB and dual task results and the absence versus the presence of depression or the absence versus the presence of apathy.

RESULTS

Of 88 patients with AD, 26 had both apathy and depression, 26 had depression only, 18 had apathy only, and 18 had neither. Total FAB scores and dual task scores differed significantly between the AD patients with depression and those without depression; the scores were also different between those with apathy and those without apathy. Also, a significant interaction between depression and apathy was noted for the total FAB and dual task scores.

CONCLUSIONS

The deficits in the total FAB and dual task scores were larger in AD patients with both apathy and depression compared with patients with either apathy or depression alone. AD patients with both symptoms may have greater deficits in frontal lobe function relative to AD patients with either apathy or depression alone.

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.