Artificial intelligence for diagnostic and prognostic neuroimaging in dementia: A systematic review.

INTRODUCTION: Artificial intelligence (AI) and neuroimaging offer new opportunities for diagnosis and prognosis of dementia. METHODS: We systematically reviewed studies reporting AI for neuroimaging in diagnosis and/or prognosis of cognitive neurodegenerative diseases. RESULTS: A total of 255 studies were identified. Most studies relied on the Alzheimer's Disease Neuroimaging Initiative dataset. Algorithmic classifiers were the most commonly used AI method (48%) and discriminative models performed best for differentiating Alzheimer's disease from controls. The accuracy of algorithms varied with the patient cohort, imaging modalities, and stratifiers used. Few studies performed validation in an independent cohort. DISCUSSION: The literature has several methodological limitations including lack of sufficient algorithm development descriptions and standard definitions. We make recommendations to improve model validation including addressing key clinical questions, providing sufficient description of AI methods and validating findings in independent datasets. Collaborative approaches between experts in AI and medicine will help achieve the promising potential of AI tools in practice. HIGHLIGHTS: There has been a rapid expansion in the use of machine learning for diagnosis and prognosis in neurodegenerative disease Most studies (71%) relied on the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset with no other individual dataset used more than five times There has been a recent rise in the use of more complex discriminative models (e.g., neural networks) that performed better than other classifiers for classification of AD vs healthy controls We make recommendations to address methodological considerations, addressing key clinical questions, and validation We also make recommendations for the field more broadly to standardize outcome measures, address gaps in the literature, and monitor sources of bias.

Test Your Memory-Spanish version (TYM-S): a validation study of a self-administered cognitive screening test.

OBJECTIVES: To develop the Test Your Memory (TYM)-Spanish version (TYM-S), a self-administered cognitive screening test, in a Chilean older sample and to estimate its psychometric properties and diagnostic accuracy. METHODS: The TYM was translated into Spanish and adapted for a Chilean population to develop the TYM-S. Measures of global cognitive impairment and executive dysfunction were administered to 30 controls, 30 dementia patients, and 14 subjects with mild cognitive impairment (MCI). All participants' proxies were interviewed with assessments of dementia severity, functionality in daily living activities, and cognitive change. Convergent validity and internal consistency reliability of the TYM-S were estimated. Cut-off points, sensitivity, and specificity were determined to test its diagnostic capacity for dementia or MCI. RESULTS: Regarding convergent validity, the TYM-S was significantly correlated (p < 0.001) with global cognitive impairment (Mini-Mental State Examination: r = 0.902; Addenbrooke's Cognitive Examination-Revised-Chilean version: r = 0.922; Montreal Cognitive Assessment: r = 0.923), executive dysfunction (Frontal Assessment Battery: r = 0.862), dementia severity (Clinical Dementia Rating: r = -0.757), functional capacity (Technology-Activities of Daily Living Questionnaire: r = -0.864; Pfeffer Functional Activities Questionnaire: r = -0.748; Instrumental Activities of Daily Living: r = 0.769), and cognitive change (Alzheimer's Disease 8-Chilean version: r = -0.700) measures. Regarding reliability, Cronbach's α was 0.776. Optimum cut-off scores of 39 and 44 distinguished dementia cases from controls (93.1% sensitivity, 82.2% specificity) and MCI cases from controls (85.7% sensitivity, 69% specificity), respectively. The extent of assistance required in the TYM-S and cognitive impairment was correlated. CONCLUSIONS: The TYM-S is a valid and reliable instrument to assess cognitive impairment, showing good psychometric properties and diagnostic capacity to identify cases of dementia in a Spanish-speaking older cohort. Although its need for assistance may be limiting, its ability to quickly assess several cognitive domains supports widespread clinical use.

Differences in Grey Matter Concentrations and Functional Connectivity between Young Carriers and Non-Carriers of the APOE ε4 Genotype.

Background: The pathophysiology of Alzheimer's disease (AD) may begin developing years or even decades prior to the manifestation of its first symptoms. The APOE ε4 genotype is a prominent genetic risk for AD that has been found to be associated with brain changes across the lifespan since early adulthood. Thus, studying brain changes that may occur in young adults with an APOE ε4 status is highly relevant. Objective: Examine potential differences in grey matter (GM) and functional connectivity (FC) in brains of cognitively healthy young APOE ε4 carriers and non-carriers, denoted here as ε4(+) and ε4(-), respectively. Methods: Three Tesla magnetic resonance imaging (MRI) brain scans were acquired from cognitively healthy young participants aged approximately 20 years (n = 151). Voxel-based morphometry (VBM) analysis was employed to identify potential structural differences in GM between ε4(+) and ε4(-). In a subsequent seed-based connectivity (SBC) analysis, brain regions that structurally differed in the VBM analysis were considered as seeds and correlated with all the remaining voxels across the brains to then measure the differences in FC between groups. Results: The VBM analysis suggested that ε4(+) (n = 28) had greater GM densities relative to ε4(-) (n = 123) in the left hippocampus and the left posterior insula (puncorr < 0.001). However, the effect did not survive the correction for multiple comparisons, suggesting minimal structural differences in this age range. In contrast, the SBC analysis indicated that ε4(+) exhibited significantly decreased FC between the left hippocampus and areas of the left middle temporal gyrus (n = 27) compared to ε4(-) (n = 102). These results remained significant after multiple comparisons (pFDR < 0.05). Lastly, no statistically significant differences in FC between groups were observed for the left insular seed (pFDR > 0.05). Discussion: These results suggest early structural and functional brain changes associated with the APOE ε4 genotype on young adults. Yet, they must be cautiously interpreted and contrasted with both older adults with genetic risk for AD and patients diagnosed with AD.

Corrigendum: L-DOPA increases slow-wave sleep duration and selectively modulates memory persistence in older adults.

[This corrects the article DOI: 10.3389/fnbeh.2023.1096720.].

Genetic risk factors of Alzheimer's Disease disrupt resting-state functional connectivity in cognitively intact young individuals.

BACKGROUND: Past evidence shows that changes in functional brain connectivity in multiple resting-state networks occur in cognitively healthy individuals who have non-modifiable risk factors for Alzheimer's Disease. Here, we aimed to investigate how those changes differ in early adulthood and how they might relate to cognition. METHODS: We investigated the effects of genetic risk factors of AD, namely APOEe4 and MAPTA alleles, on resting-state functional connectivity in a cohort of 129 cognitively intact young adults (aged 17-22 years). We used Independent Component Analysis to identify networks of interest, and Gaussian Random Field Theory to compare connectivity between groups. Seed-based analysis was used to quantify inter-regional connectivity strength from the clusters that exhibited significant between-group differences. To investigate the relationship with cognition, we correlated the connectivity and the performance on the Stroop task. RESULTS: The analysis revealed a decrease in functional connectivity in the Default Mode Network (DMN) in both APOEe4 carriers and MAPTA carriers in comparison with non-carriers. APOEe4 carriers showed decreased connectivity in the right angular gyrus (size = 246, p-FDR = 0.0079), which was correlated with poorer performance on the Stroop task. MAPTA carriers showed decreased connectivity in the left middle temporal gyrus (size = 546, p-FDR = 0.0001). In addition, we found that only MAPTA carriers had a decreased connectivity between the DMN and multiple other brain regions. CONCLUSIONS: Our findings indicate that APOEe4 and MAPTA alleles modulate brain functional connectivity in the brain regions within the DMN in cognitively intact young adults. APOEe4 carriers also showed a link between connectivity and cognition.

L-DOPA increases slow-wave sleep duration and selectively modulates memory persistence in older adults.

Introduction: Millions of people worldwide take medications such as L-DOPA that increase dopamine to treat Parkinson's disease. Yet, we do not fully understand how L-DOPA affects sleep and memory. Our earlier research in Parkinson's disease revealed that the timing of L-DOPA relative to sleep affects dopamine's impact on long-term memory. Dopamine projections between the midbrain and hippocampus potentially support memory processes during slow wave sleep. In this study, we aimed to test the hypothesis that L-DOPA enhances memory consolidation by modulating NREM sleep. Methods: We conducted a double-blind, randomised, placebo-controlled crossover trial with healthy older adults (65-79 years, n = 35). Participants first learned a word list and were then administered long-acting L-DOPA (or placebo) before a full night of sleep. Before sleeping, a proportion of the words were re-exposed using a recognition test to strengthen memory. L-DOPA was active during sleep and the practice-recognition test, but not during initial learning. Results: The single dose of L-DOPA increased total slow-wave sleep duration by approximately 11% compared to placebo, while also increasing spindle amplitudes around slow oscillation peaks and around 1-4 Hz NREM spectral power. However, behaviourally, L-DOPA worsened memory of words presented only once compared to re-exposed words. The coupling of spindles to slow oscillation peaks correlated with these differential effects on weaker and stronger memories. To gauge whether L-DOPA affects encoding or retrieval of information in addition to consolidation, we conducted a second experiment targeting L-DOPA only to initial encoding or retrieval and found no behavioural effects. Discussion: Our results demonstrate that L-DOPA augments slow wave sleep in elderly, perhaps tuning coordinated network activity and impacting the selection of information for long-term storage. The pharmaceutical modification of slow-wave sleep and long-term memory may have clinical implications. Clinical trial registration: Eudract number: 2015-002027-26; https://doi.org/10.1186/ISRCTN90897064, ISRCTN90897064.

The technology - activities of daily living questionnaire: a version with a technology-related subscale.

BACKGROUND: Information and communication technology (ICT) has become an increasingly important part of daily life. The ability to use technology is becoming essential for autonomous functioning in society. Current functional scales for patients with cognitive impairment do not evaluate the use of technology. The objective of this study was to develop and validate a new version of the Activities of Daily Living Questionnaire (ADLQ) that incorporates an ICT subscale. METHOD: A new technology-based subscale was incorporated into the Spanish version of the ADLQ (SV-ADLQ), entitled the Technology version of the ADLQ (T-ADLQ). The T-ADLQ was administered to 63 caregivers of dementia patients, 21 proxies of mild cognitive impairment patients and 44 proxies of normal elderly subjects (mean age of the sample ± SD: 73.5 ± 8.30 years). We analysed the convergent validity, internal consistency, reliability cut-off point, sensitivity and specificity of the T-ADLQ. The results of the T-ADLQ were compared to the SV-ADLQ. RESULTS: The T-ADLQ showed significant correlations with the Mini-Mental State Examination (MMSE), the Frontal Assessment Battery (FAB) as well as other measures of functional impairment and dementia severity (MMSE: r = -0.70; FAB: r = -0.65; Functional Assessment Questionnaire: r = 0.77; Instrumental Activities of Daily Living Scale: r = -0.75; Clinical Dementia Rating Scale: r = 0.72; p < 0.001). The T-ADLQ showed a good reliability with a relatively high Cronbach's α-coefficient (Cronbach's α = 0.861). When considering a functional impairment cut-off point greater than 29.25%, the sensitivity and specificity of the T-ADLQ were 82 and 90%, respectively. The area under the receiver-operating characteristic curve was 0.937 for the T-ADLQ and 0.932 for the original version of the test. CONCLUSIONS: The T-ADLQ revealed adequate indicators of validity and reliability for the functional assessment of activities of daily living in dementia patients. However, the inclusion of technology items in the T-ADLQ did not improve the performance of the scale, which may reflect the lack of widespread use of technology by elderly individuals. Thus, although it appeared reasonable to add technology use questions to the ADLQ, our experience suggested that this has to be done cautiously, since the sensitivity of these additional items could vary in different populations. The T-ADLQ needs to be validated in a different population of dementia subjects.

[Psychometric properties and diagnostic usefulness of the Addenbrooke's Cognitive Examination-Revised in a Chilean elderly sample]. / Propiedades psicométricas y utilidad diagnóstica del Addenbrooke's Cognitive Examination-Revised (ACE-R) en una muestra de ancianos chilenos.

BACKGROUND: The Addenbrooke's Cognitive Examination - Revised (ACE-R) is a good alternative to the Mini Mental State Examination (MMSE) for assessing cognitive capacities in dementia. AIM: To estimate the psychometric properties and diagnostic utility of the Addenbrooke's Cognitive Examination-Revised (ACE-R) in a Chilean elderly sample. MATERIAL AND METHODS: ACE-R was adapted for the Chilean population (ACE-R-Ch) and then administered to 60 dementia patients, 22 mild cognitive impairment (MCI) patients and 45 control subjects in addition to the MMSE for assessing global cognitive efficiency. Caregivers of dementia patients and collateral sources of MCI patients and elderly subjects without dementia were interviewed with measures of dementia severity, functional status in activities of daily living and cognitive changes. Convergent validity, internal consistency reliability, cutoff points, sensitivity and specificity for ACE-R-Ch were estimated. RESULTS: Regarding convergent validity, the ACE-R-Ch showed significant correlations (p < 0,001) with another cognitive measure (r = 0,952 with MMSE), a rating for dementia severity (Spearman rho=-0,822 with CDR), functional capacity assessments (r = -0,70 with ADLQ-Ch; r = -0,725 with PFAQ-Ch; and r = 0,650 with IADL Scale) and a measure of cognitive changes (r = -0,633 with AD8-Ch). In terms of reliability, the test had a Cronbach alpha coefficient of 0.918. The best cut-off point to distinguish cases of dementia from control subjects was a score of 76, which reached a sensitivity of 0.92 and a specificity of 0.93. CONCLUSIONS: The ACE-R-Ch showed acceptable psychometric properties, becoming a valid and reliable instrument to assess global cognitive efficiency or cognitive impairment. Its diagnostic utility to detect dementia patients also worked very well in a Chilean elderly sample.

[Prognostic heterogeneity of attention deficit/hyperactivity disorder in adults]. / Descomponiendo el síndrome de déficit atencional en el adulto: hacia un entendimiento de su heterogeneidad pronóstica.

Attention Deficit/Hyperactivity Disorder (ADHD) is a clinical syndrome characterized by an onset in early life. More than 65% of patients persist with manifestations of ADHD in adulthood. These symptoms may interfere in activities of daily-living, interpersonal relationships and professional and academic achievement. Nevertheless, the observation of an important group of adults with ADHD who do not show significant difficulties in the areas mentioned before puts into evidence the prognostic heterogeneity of this disorder. One of the current, most accepted explanations is the Double-Pathway Model: two double-dissociated deficits (Executive Disorders and Delayed-Reward Processing impairments) are involved in the genesis of ADHD, which explains the existence of different behavioral phenotypes. Moreover, personality traits like tenacity or perseverance are associated with higher levels of achievement in adults. On these grounds, we propose the hypothesis that the neurobiological correlate of tenacity/perseverance is a preserved Delayed-Reward Processing capacity, although further studies are needed to verify this idea.

Alzheimer's Disease or Behavioral Variant Frontotemporal Dementia? Review of Key Points Toward an Accurate Clinical and Neuropsychological Diagnosis.

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most common neurodegenerative early-onset dementias. Despite the fact that both conditions have a very distinctive clinical pattern, they present with an overlap in their cognitive and behavioral features that may lead to misdiagnosis or delay in diagnosis. The current review intends to summarize briefly the main differences at the clinical, neuropsychological, and behavioral levels, in an attempt to suggest which aspects would facilitate an adequate diagnosis in a clinical setting, especially in Latin American and low- and middle-income countries, where the resources needed for a differential diagnosis (such as MRI or biomarkers) are not always available. A timely diagnosis of AD and FTD have significant implications for the medical management and quality of life of patients and careers.

Neural correlates of altered insight in frontotemporal dementia: a systematic review.

Altered insight into disease or specific symptoms is a prominent clinical feature of frontotemporal dementia (FTD). Understanding the neural bases of insight is crucial to help improve FTD diagnosis, classification and management. A systematic review to explore the neural correlates of altered insight in FTD and associated syndromes was conducted. Insight was fractionated to examine whether altered insight into different neuropsychological/behavioural objects is underpinned by different or compatible neural correlates. 6 databases (Medline, Embase, PsycINFO, Web of Science, BIOSIS and ProQuest Dissertations & Theses Global) were interrogated between 1980 and August 2019. 15 relevant papers were found out of 660 titles screened. The studies included suggest that different objects of altered insight are associated with distinctive brain areas in FTD. For example, disease unawareness appears to predominantly correlate with right frontal involvement. In contrast, altered insight into social cognition potentially involves, in addition to frontal areas, the temporal gyrus, insula, parahippocampus and amygdala. Impaired insight into memory problems appears to be related to the frontal lobes, postcentral gyrus, parietal cortex and posterior cingulate. These results reflect to a certain extent those observed in other neurodegenerative conditions like Alzheimer's disease (AD) and also other brain disorders. Nevertheless, they should be cautiously interpreted due to variability in the methodological aspects used to reach those conclusions. Future work should triangulate different insight assessment approaches and brain imaging techniques to increase the understanding of this highly relevant clinical phenomenon in dementia.

Mapping the neuroanatomy of functional decline in Alzheimer's disease from basic to advanced activities of daily living.

BACKGROUND: Impairments in activities of daily living (ADL) are a criterion for Alzheimer's disease (AD) dementia. However, ADL gradually decline in AD, impacting on advanced (a-ADL, complex interpersonal or social functioning), instrumental (IADL, maintaining life in community), and finally basic functions (BADL, activities related to physiological and self-maintenance needs). Information and communication technologies (ICT) have become an increasingly important aspect of daily functioning. Yet, the links of ADL, ICT, and neuropathology of AD dementia are poorly understood. Such knowledge is critical as it can provide biomarker evidence of functional decline in AD. METHODS: ADL were evaluated with the Technology-Activities of Daily Living Questionnaire (T-ADLQ) in 33 patients with AD and 30 controls. ADL were divided in BADL, IADL, and a-ADL. The three domain subscores were covaried against gray matter atrophy via voxel-based morphometry. RESULTS: Our results showed that three domain subscores of ADL correlate with several brain structures, with a varying degree of overlap between them. BADL score correlated mostly with frontal atrophy, IADL with more widespread frontal, temporal and occipital atrophy and a-ADL with occipital and temporal atrophy. Finally, ICT subscale was associated with atrophy in the precuneus. CONCLUSIONS: The association between ADL domains and neurodegeneration in AD follows a traceable neuropathological pathway which involves different neural networks. This the first evidence of ADL phenotypes in AD characterised by specific patterns of functional decline and well-defined neuropathological changes. The identification of such phenotypes can yield functional biomarkers for dementias such as AD.

Neuroanatomical Comparison of the "Word" and "Picture" Versions of the Free and Cued Selective Reminding Test in Alzheimer's Disease.

Episodic memory tests with cued recall, such as the Free and Cued Selective Reminding Test (FCSRT), allow for the delineation of hippocampal and prefrontal atrophy contributions to memory performance in Alzheimer's disease (AD). Both Word and Picture versions of the test exist but show different profiles, with the Picture version usually scoring higher across different cohorts. One possible explanation for this divergent performance between the different modality versions of the test might be that they rely on different sets of neural correlates. The current study explores this by contrasting the neural correlates of the Word and Picture versions of the FCSRT with voxel-based morphometry (VBM) in AD and healthy subjects. We predicted that the Picture version would be associated with different cortical regions than the Word version, which might be more hippocampal-centric. When comparing 35 AD patients and 34 controls, AD patients exhibited impairments on both versions of the FCSRT and both groups performed higher in the Picture version. A region of interest analysis based on prior work revealed significant correlations between free recall of either version with atrophy of the temporal pole and hippocampal regions. Thus, contrary to expectations, performance on both the Word and the Picture version of the FCSRT is associated with largely overlapping networks. Free recall is associated with hippocampal volume and might be properly considered as an indicator of hippocampal structural integrity.

Utility of the Neuropsychiatric Inventory Questionnaire (NPI-Q) in the assessment of a sample of patients with Alzheimer's disease in Chile.

The Neuropsychiatric Inventory Questionnaire (NPI-Q) is an informant-based instrument that measures the presence and severity of 12 Neuropsychiatric Symptoms (NPS) in patients with dementia, as well as informant distress. OBJECTIVE: To measure the psychometric properties of the NPI-Q and the prevalence of NPS in patients with Alzheimer's disease (AD) in Chile. METHODS: 53 patients with AD were assessed. Subjects were divided into two different groups: mild AD (n=26) and moderate AD (n=27). Convergent validity was estimated by correlating the outcomes of the NPI-Q with Neuropsychiatric Inventory (NPI) scores and with a global cognitive efficiency test (Addenbrooke's Cognitive Examination - Revised - ACE-R). Reliability of the NPI-Q was analysed by calculating its internal consistency. Prevalence of NPS was estimated with both the NPI and NPI-Q. RESULTS: Positive and significant correlations were observed between the NPI-Q, the NPI, and the ACE-R (r=0.730; p<0.01 and 0.315; p<0.05 respectively). The instrument displayed an adequate level of reliability (Cronbach's alpha=0.783). The most prevalent NPS were apathy/indifference (62.3%) and dysphoria/depression (58.5%). CONCLUSION: The NPI-Q exhibited acceptable validity and reliability indicators for patients with AD in Chile, indicating that it is a suitable instrument for the routine assessment of NPS in clinical practice.

O Questionário de Inventário Neuropsiquiátrico (NPI-Q) é um instrumento baseado em informantes que mede a presença e a gravidade de 12 Sintomas Neuropsiquiátricos (NPS) em pacientes com demência, bem como o sofrimento do informante. OBJETIVO: Avaliar as propriedades psicométricas do NPI-Q e a prevalência de NPS em pacientes com doença de Alzheimer (DA). MÉTODOS: Foram avaliados 53 pacientes com DA. Eles foram divididos em dois grupos diferentes: AD leve (n=26) e AD moderado (n=27). A validade convergente foi estimada correlacionando os resultados do NPI-Q com os escores do Inventário Neuropsiquiátrico (NPI) e um teste de eficiência cognitiva global (Addenbrooke's Cognitive Examination - Revised - ACE-R). A confiabilidade do NPI-Q foi analisada pelo cálculo da sua consistência interna. A prevalência de NPS foi estimada com NPI e NPI-Q. RESULTADOS: Foram observadas correlações positivas e significativas entre NPI-Q, NPI e ACE-R (r=0,730; p<0,01 e 0>315; p<0>05). O instrumento apresentou um nível adequado de confiabilidade (alfa de Cronbach=0J83). Os NPS mais prevalentes foram apatia/indiferença (62,3%) e disforia/depressão (58,5%). CONCLUSÃO: O NPI-Q apresenta indicadores de validade e confiabilidade aceitáveis em pacientes com DA, o que indica que é um instrumento adequado para a avaliação rotineira de NPS na prática clínica.

Tau Platelets Correlate with Regional Brain Atrophy in Patients with Alzheimer's Disease.

BACKGROUND: Intracellular neurofibrillary tangles are part of the core pathology of Alzheimer's disease (AD), which are mainly composed of hyperphosphorylated tau protein. OBJECTIVES: The purpose of this study is to determine whether high molecular weight (HMW) or low molecular weight (LMW) tau protein levels, as well as the ratio HMW/LMW, present in platelets correlates with brain magnetic resonance imaging (MRI) structural changes in normal and cognitively impaired subjects. METHODS: We examined 53 AD patients and 37 cognitively normal subjects recruited from two Memory Clinics at the Universidad de Chile. Tau levels in platelets were determined by immunoreactivity and the MRI scans were analyzed using voxel-based morphometry in 41 AD patients. RESULTS: The HMW/LMW tau ratio was statistically different between controls and AD patients, and no associations were noted between HMW or LMW tau and MRI structures. In a multivariate analysis controlled for age and education level, the HMW/LMW tau ratio was associated with reduced volume in the left medial and right anterior cingulate gyri, right cerebellum, right thalamus (pulvinar), left frontal cortex, and right parahippocampal region. CONCLUSIONS: This exploratory study showed that HMW/LMW tau ratio is significantly higher in AD patients than control subjects, and that it is associated with specific brain regions atrophy. Determination of peripheral markers of AD pathology can help understanding the pathophysiology of neurodegeneration in AD.

Comparison of the Psychometric Properties of the "Word" and "Picture" Versions of the Free and Cued Selective Reminding Test in a Spanish-Speaking Cohort of Patients with Mild Alzheimer's Disease and Cognitively Healthy Controls.

The aim of this study was to compare the psychometric properties of the "Word" and "Picture" versions of the Spanish FCSRT across the same sample of mild Alzheimer disease (AD) patients and controls. Mild AD patients (N = 50, 27 CDR = 0.5; 23 CDR = 1) and controls (N = 42, CDR = 0) were assessed with an extensive clinical and neuropsychological evaluation. Psychometric characteristics for both versions of the FCSRT were compared. Free recall (FR) and total recall (TR) across both versions of the FCSRT showed areas under the curve >0.9 and did not significantly differ between them. The scores of both versions were well correlated, although the scores for the Picture version were greater than those for the Word version, particularly for the TR scores of the mild AD group. Both versions of the FCSRT showed an appropriate accuracy to distinguish mild AD patients and controls. Visual cues were easier to recall than verbal cues, especially in the memory impaired patients.

Psychosis-related matricide associated with a lesion of the ventromedial prefrontal cortex.

Matricide, the killing of a mother by her biological child, is a rare event. We report a case of matricide associated with a woman who sustained a right ventromedial prefrontal lesion during surgery for nasal polyposis that was performed when she was 40 years old. After her surgery, she developed psychotic symptoms associated with the emergence of antisocial behavior. She committed matricide 22 years later. Neuropsychological evaluation showed decreased frontal-executive deficits, and magnetic resonance imaging revealed a lesion in the right gyrus rectus area of the ventromedial prefrontal region. This case suggests that a secondary psychotic syndrome associated with a lesion in the frontal neural network, which is disturbed in psychopathy, could facilitate homicidal behavior. Furthermore, this case has legal implications for the prosecution of murder associated with a brain lesion.

Chilean version of the INECO Frontal Screening (IFS-Ch): psychometric properties and diagnostic accuracy.

OBJECTIVE: This study sought to analyze the psychometric properties and diagnostic accuracy of the Chilean version of the INECO Frontal Screening (IFS-Ch) in a sample of dementia patients and control subjects. METHODS: After adapting the instrument to the Chilean context and obtaining content validity evidence through expert consultation, the IFS-Ch was administered to 31 dementia patients and 30 control subjects together with other executive assessments (Frontal Assessment Battery [FAB], Modified version of the Wisconsin Card Sorting Test [MCST], phonemic verbal fluencies [letters A and P] and semantic verbal fluency [animals]) and global cognitive efficiency tests (Mini mental State Examination [MMSE] and Addenbrooke's Cognitive Examination-Revised [ACE-R]). Caregivers of dementia patients and proxies of control subjects were interviewed with instruments measuring dysexecutive symptoms (Dysexecutive Questionnaire [DEX]), dementia severity (Clinical Dementia Rating Scale [CDR]) and functional status in activities of daily living (Activities of Daily Living Scale [IADL] and Technology-Activities of Daily Living Questionnaire [T-ADLQ]). Convergent and discriminant validity, internal consistency reliability, cut-off points, sensitivity and specificity for the IFS-Ch were estimated. RESULTS: Evidence of content validity was obtained. Evidence of convergent validity was also found showing significant correlations (p<0.05) between the IFS-Ch and the other instruments measuring: executive functions (FAB, r=0.935; categories achieved in the MCST, r=0.791; perseverative errors in the MCST, r= -0.617; animal verbal fluency, r=0.728; "A" verbal fluency, r=0.681; and "P" verbal fluency, r=0.783), dysexecutive symptoms in daily living (DEX, r= -0.494), dementia severity (CDR, r= -0.75) and functional status in activities of daily living (T-ADLQ, r= -0.745; IADL, r=0.717). Regarding reliability, a Cronbach's alpha coefficient of 0.905 was obtained. For diagnostic accuracy, a cut-off point of 18 points (sensitivity=0.903; specificity=0.867) and an area under curve of 0.951 were estimated to distinguish between patients with dementia and control subjects. DISCUSSION: The IFS-Ch showed acceptable psychometric properties, supported by evidence of validity and reliability for its use in the measurement of executive functions in patients with dementia. The diagnostic accuracy of the IFS-Ch for detecting dementia patients was also considered acceptable.

OBJETIVO: Analisar as propriedades psicométricas e utilitário de diagnóstico da versão chilena do rastreio frontal INECO (IFS-Ch) em uma amostra de pacientes com demência e controles. MÉTODOS: Após a adaptação do instrumento para o contexto chileno e obtenção de evidências de validade de conteúdo, o IFS-Ch foi administrado a 31 pacientes com demência e 30 indivíduos do grupo controle, além de outros testes de eficiência cognitiva global e executiva. Cuidadores de pacientes com demência e informantes de indivíduos controles foram entrevistados com instrumentos de medidas de sintomas disexecutivos, gravidade da demência e estado funcional nas atividades da vida diária. Validade convergente e discriminante, consistência interna, pontos de corte, sensibilidade e especificidade para o IFS-Ch foram estimados. RESULTADOS: A evidência de validade de conteúdo foi obtida através de consulta a um especialista. Evidências de validade convergente foram encontrados, bem como, descritas correlações significativas entre o IFS-Ch e outros instrumentos de medidas: de funções executivas (FAB, r=0,935; categorias alcançadas no MCST, r=0,791; erros perseverativos na MCST, r= -0,617; fluência verbal animais, r=0,728; "A" de fluência verbal, r=0,681; gravidade de demência e fluência verbal de "P", r=0,783), sintomas disexecutivos na vida diária (DEX, r= -0,494), (CDR, r= -0,75) e estado funcional nas atividades da vida diária (T-ADLQ, r= -0,745; AIVD, r=0,717). Quanto à confiabilidade, coeficiente alfa de Cronbach de 0,905 foi obtido. Quanto a utilidade de diagnóstico, um ponto de corte de 18 pontos (sensibilidade=0,903, especificidade=0,867) e uma área sob a curva de 0,951 foi estimada para distinguir entre pacientes com demência e sujeitos controles. DISCUSSÃO: O IFS-Ch mostra propriedades psicométricas aceitáveis, apoiadas por evidências de validade e confiabilidade para sua utilização como medida de funções executivas em pacientes com demência. Sua utilidade diagnóstica para detectar pacientes com demência também é considerada aceitável.

The CUIDEME Study: determinants of burden in chilean primary caregivers of patients with dementia.

BACKGROUND: Caring for a person with dementia is associated with well-documented increases in burden and distress and decreases in mental health and wellbeing. Studies assessing burden in caregivers of patients with dementia and its determinants are scarce in Latin America. OBJECTIVE: The main objective of this study was to assess the extent and the determinants of burden in informal primary caregivers of patients with dementia in Chile. METHODS: A descriptive study was conducted using clinically validated scales to assess dementia characteristics and to measure caregiver variables. Family socio-demographic characteristics and functional status, patient functional dependency and behavioral disturbances, and caregiver psychiatric morbidity were analyzed as independent variables to determine caregiver burden. RESULTS: Two hundred and ninety-two informal caregivers were included. There were more female (80%) than male caregivers, consisting mainly of daughters and spouses of the patients. Severe burden was reported in 63% of the caregivers, and 47% exhibited psychiatric morbidity. Burden was associated with caregiver psychiatric distress, family dysfunction, severity of neuropsychiatric symptoms and functional disability, but neither patient age, gender, nor socioeconomic status impacted burden. CONCLUSION: Our results underscore the importance of assessing the consequences of dementia in both caregivers and patients in order to evaluate the real biopsychosocial impact of dementia, as well as the importance of planning appropriate and effective public health interventions in Latin American countries. In addition, interventions targeting caregiver psychological distress, caregiver familial dysfunction, patient neuropsychiatric disorders, and patient functional disability could potentially diminish caregiver burden.