Evaluating Semantic Knowledge Through a Semantic Association Task in Individuals With Dementia.

Conceptual knowledge is supported by multiple semantic systems that are specialized for the analysis of different properties associated with object concepts. Various types of semantic association between concrete concepts-categorical (CA), encyclopedic (EA), functional (FA), and visual-encyclopedic (VEA) associations-were tested through a new picture-to-picture matching task (semantic association task, SAT). Forty individuals with Alzheimer's disease (AD), 13 with behavioral variant of frontotemporal dementia (bv-FTD), 6 with primary progressive aphasia (PPA), and 37 healthy participants were tested with the SAT. Within-group comparisons highlighted a global impairment of all types of semantic association in bv-FTD individuals but a disproportionate impairment of EA and FA, with relative sparing of CA and VEA, in AD individuals. Single-case analyses detected dissociations in all dementia groups. Conceptual knowledge can be selectively impaired in various types of neurodegenerative disease on the basis of the specific cognitive process that is disrupted.

Anxiety and Depression Are Not Related to Increasing Levels of Burden and Stress in Caregivers of Patients With Alzheimer's Disease.

Sixty-nine dyads of patients with Alzheimer's disease and primary caregivers have been followed up for 1 year to evaluate cognitive (Mini-Mental State Examination), functional (Instrumental Activities of Daily Living), and behavioral (Neuropsychiatric Inventory) decline of patient in relation to burden (Caregiver Burden Inventory), stress (Relative Stress Scale), anxiety (State-Trait Anxiety Inventory Y), and depression (Beck Depression Inventory) reported by the caregivers. After 1 year of observation, cognitive and functional scores worsened while behavioral problems remained unchanged and relatively mild in patients. After 1 year, caregivers' scores of scales of anxiety and depression decreased significantly, while stress scores remained unchanged and burden slightly increased. In our opinion, the unexpected improvement in psychological situation of caregivers may be mainly due to educational interventions focused on knowledge of the disease with a particular attention directed toward emotional support and individual needs.

Complexity in neuropsychological assessments of cognitive impairment: A network analysis approach.

In a neuropsychological assessment, each test aims at measuring a single cognitive function. However, test performance depends on an interconnected system of cognitive functions and individual characteristics. For a better understanding of cognitive deficits, it is fundamental to recognize this complexity and study the relationships between test performances. This study aims to evaluate complexity in neuropsychological assessment through network analysis (NA) in 165 healthy older adults, 191 patients with Alzheimer's disease (AD), and 129 patients with vascular encephalopathy (VaE). NA is a flexible method to explore different domains where many variables are correlated with each other, and the relationships are key for understanding the domains. We included general aspects of individual differences (i.e., age, sex, years of education) and the raw scores of a clinically used neuropsychological battery in the network. Healthy subjects showed a segregated pattern, suggesting a good specificity of each test in measuring a specific cognitive function. Moreover, the scores were related to age and education. In the patient groups, the identified patterns changed in a consistent manner, showing less specificity and new relationships between the various tests, thereby reducing the impact of age and education on the performance. In particular, AD patients showed worse performance on the tests but also a different balance between different tasks, suggesting a reorganization of the cognitive system and not a mere decline. These results provide a new perspective in looking at the complexity of cognitive function assessment.

When Rey-Osterrieth's Complex Figure Becomes a Church: Prevalence and Correlates of Graphic Confabulations in Dementia.

Verbal confabulation (VC) has been described in several pathological conditions characterized by amnesia and has been defined as 'statements that involve distortion of memories'. Here we describe another kind of confabulation (graphic confabulation, GC), evident at the recall of the Rey-Osterrieth complex figure (ROCF). In a retrospective study of 267 patients with mild-to-moderate dementia, 14 patients (4.9 %) recalled the abstract ROCF as drawings with recognizable semantic meaning. VC was evident at the story recall test in 19.8% of the study participants. VC and GC were homogeneously distributed among the different types of dementia. VC has been proposed to originate from complex interactions of amnesia, motivational deficit and dysfunction of monitoring systems. On the contrary, GC seems to be the result of a deficit in visual memory replaced by the semantic translation of isolated parts of the ROCF along with a source monitoring deficit.

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

BACKGROUND: An early differentiation of Alzheimer's disease (AD) from frontotemporal dementia (FTD) is important, since these conditions are essentially different regarding prognosis and therapeutical approach. Until now, no single test is available which allows a reliable differentiation. The Frontal Assessment Battery (FAB) has been found to have good reliability in identifying an executive deficit in frontal syndromes and in extrapyramidal disorders. The ability of the FAB to distinguish AD from FTD in mildly demented patients is less clearly assessed. METHODS: We compared FAB scores in a consecutive series of 33 FTD (frontal variant) and 85 AD patients. RESULTS: FAB global scores in the two groups were very similar, also when considering only mildly demented subgroups [Mini Mental State Examination (MMSE) score > or = 20; 20 FTD and 38 AD patients]. Considering FAB subscores, only the 'go-no go' subtest showed a significant difference, reflecting a poorer inhibitory motor control in AD patients. FAB scores in the two groups of patients correlated with global cognitive decline (MMSE), and with executive and visuospatial test scores, showing good concurrent validity. CONCLUSION: The FAB does not differentiate patients with AD from those with FTD, like all other executive tests. However, it may be useful in the examination of executive function in AD, FTD and several other pathological conditions.