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

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

BPSDiary study protocol: a multi-center randomized controlled trial to compare the efficacy of a BPSD diary vs. standard care in reducing caregiver's burden

Behavioral and Psychological Symptoms of Dementia (BPSD) are a heterogeneous set of psychological and behavioral abnormalities seen in persons with dementia (PwD), significantly impacting their quality of life and that of their caregivers. Current assessment tools, such as the Neuropsychiatric Inventory (NPI), are limited by recall bias and lack of direct observation. This study aims to overcome this limitation by making caregiver reports more objective through the use of a novel instrument, referred to as the BPSDiary. This randomized controlled trial will involve 300 caregiver-PwD dyads. The objective is to evaluate whether the use of the BPSDiary could significantly reduce caregiver burden, assessed using the Zarit Burden Interview (ZBI), compared to usual care. The study will include adult PwD, caregivers living with or close to the patient, and BPSD related to the HIDA (hyperactivity, impulsivity, irritability, disinhibition, aggression, agitation) domain. Caregivers randomized to the intervention arm will use the BPSDiary to record specific BPSD, including insomnia, agitation/anxiety, aggression, purposeless motor behavior, and delusions/hallucinations, registering time of onset, severity, and potential triggers. The primary outcome will be the change in ZBI scores at 3 months, with secondary outcomes including changes in NPI scores, olanzapine equivalents, NPI-distress scores related to specific BPSD domains, and caregiver and physician satisfaction. The study will be conducted in 9 Italian centers, representing diverse geographic and sociocultural contexts. While potential limitations include the relatively short observation period and the focus on specific BPSD disturbances, the BPSDiary could provide physicians with objective data to tailor appropriate non-pharmacological and pharmacological interventions. Additionally, it may empower caregivers by encouraging reflection on BPSD triggers, with the potential to improve the quality of life for both PwD and their caregivers.Trial registryNCT05977855

Clinical and neuropathological phenotype associated with the novel V189I mutation in the prion protein gene

Prion diseases are neurodegenerative disorders which are caused by an accumulation of the abnormal, misfolded prion protein known as scrapie prion protein (PrPSc). These disorders are unique as they occur as sporadic, genetic and acquired forms. Sporadic Creutzfeldt-Jakob Disease (CJD) is the most common human prion disease, accounting for approximately 85-90% of cases, whereas autosomal dominant genetic forms, due to mutations in the prion protein gene (PRNP), account for 10-15% of cases. Genetic forms show a striking variability in their clinical and neuropathological picture and can sometimes mimic other neurodegenerative diseases. We report a novel PRNP mutation (V189I) in four CJD patients from three unrelated pedigrees. In three patients, the clinical features were typical for CJD and the diagnosis was pathologically confirmed, while the fourth patient presented with a complex phenotype including rapidly progressive dementia, behavioral abnormalities, ataxia and extrapyramidal features, and the diagnosis was probable CJD by current criteria, on the basis of PrPSc detection in CSF by Real Time Quaking-Induced Conversion assay. In all the three patients with autopsy findings, the neuropathological analysis revealed diffuse synaptic type deposition of proteinase K-resistant prion protein (PrPres), and type 1 PrPres was identified in the brain by western blot analysis. So, the histopathological and biochemical profile associated with the V189I mutation was indistinguishable from the MM1/MV1 subtype of sporadic CJD. Our findings support a pathogenic role for the V189I PRNP variant, confirm the heterogeneity of the clinical phenotypes associated to PRNP mutations and highlight the importance of PrPSc detection assays as diagnostic tools to unveil prion diseases presenting with atypical phenotypes

Condition- and context-dependent variation of sexual dimorphism across lizard populations at different spatial scales

: The evolution of sexual dimorphism (SD) is driven by intricate interplays between sexual and natural selection. When it comes to SD variation within populations, however, environmental factors play a major role. Sexually selected traits are expected to be strongly dependent on individual body condition, which is influenced by the local environment that individuals experience. As a consequence, the degree of SD may also depend on resource availability. Here, we investigated the potential drivers of SD expression at two sexually dimorphic morphometric traits, body size (snout vent length) and head shape (head geometric morphometrics), in the Italian wall lizard (Podarcis siculus). We assessed the existence of condition- and context-dependent SD across ten islands of the Aeolian archipelago (southern Italy), at within- and among-population scales. We observed strong geographical variation of SD among islands, and tested three potential SD predictors related to resource availability (individual body condition, ecosystem productivity, temperature). Body condition and ecosystem productivity were the main drivers of body size SD variation, and body condition was also the main driver for head shape SD. Our results highlight that the expression of SD in the Italian wall lizard is both condition- and context-dependent. These results are congruent at within- and among-populations scales highlighting that spatial multi-scale analysis represents a useful approach to understand patterns of SD expression

Condition- and context-dependent variation of sexual dimorphism across lizard populations at different spatial scales

The evolution of sexual dimorphism (SD) is driven by intricate interplays between sexual and natural selection. When it comes to SD variation within populations, however, environmental factors play a major role. Sexually selected traits are expected to be strongly dependent on individual body condition, which is influenced by the local environment that individuals experience. As a consequence, the degree of SD may also depend on resource availability. Here, we investigated the potential drivers of SD expression at two sexually dimorphic morphometric traits, body size (snout vent length) and head shape (head geometric morphometrics), in the Italian wall lizard (Podarcis siculus). We assessed the existence of condition- and context-dependent SD across ten islands of the Aeolian archipelago (southern Italy), at within- and among-population scales. We observed strong geographical variation of SD among islands, and tested three potential SD predictors related to resource availability (individual body condition, ecosystem productivity, temperature). Body condition and ecosystem productivity were the main drivers of body size SD variation, and body condition was also the main driver for head shape SD. Our results highlight that the expression of SD in the Italian wall lizard is both condition- and context-dependent. These results are congruent at within- and among-populations scales highlighting that spatial multi-scale analysis represents a useful approach to understand patterns of SD expression