Categoría: Papers con abstracts

Introduction: The development of screening tools for the assessment of cognitive status in patients with dementia must be brief yet both highly sensitive and specific in order to ensure its clinical utility. In this sense, it is important to adapt tools widely used around the world to particular populations, allowing for a more proper validity of its use in everyday clinical practice. One of the most popular general cognitive screening tools is the Addenbrooke´s Cognitive Examination (ACE), which has been adapted and validated in multiple languages and populations. Objective: To assess the usefulness of the Peruvian version of the ACE in patients with dementia. Materials and methods: Healthy controls, patients with Alzheimer disease (AD) and patients with Frontotemporal Dementia (FTD) were assessed with the Peruvian version of the ACE, the ADAScog to determine dementia severity, and a complete neuropsychological battery. Results: The Peruvian version of the ACE showed very good internal con- sistency, strong concurrent validity as revealed by significant correlations between the ACE total score and both the MMSE and ADAScog. The ACE was able to differentiate healthy controls from patients with dementia with high discriminatory accuracy. Using a cut-off score of 86 (out of 100), the ACE was exhibited a sensitivity of 100% and a specificity of 100%.

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.

INTRODUCTION: The processing of the emotion of disgust is attributed to the insular cortex (IC), which is also responsible for social emotions and higher-cognitive functions. We distinguish the role of the IC from its connections in regard to these functions through the assessment of emotions and social cognition in a double case report. These subjects were very rare cases that included a focal IC lesion and a subcortical focal stroke affecting the connections of the IC with frontotemporal areas. MATERIALS & METHODS: Both patients and a sample of 10 matched controls underwent neuropsychological and affective screening questionnaires, a battery of multimodal basic emotion recognition tests, an emotional inference disambiguation task using social contextual clues, an empathy task and a theory of mind task. RESULTS: The insular lesion (IL) patient showed no impairments in emotion recognition and social emotions and presented with a pattern of delayed reaction times (RTs) in a subset of both groups of tasks. The subcortical lesion (SL) patient was impaired in multimodal aversive emotion recognition, including disgust, and exhibited delayed RTs and a heterogeneous pattern of impairments in subtasks of empathy and in the contextual inference of emotions. CONCLUSIONS: Our results suggest that IC related networks, and not the IC itself, are related to negative emotional processing and social emotions. We discuss these results with respect to theoretical approaches of insular involvement in emotional and social processing and propose that IC connectivity with frontotemporal and subcortical regions might be relevant for contextual emotional processing and social cognition.

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.

La escala de impulsividad de Barratt es un instrumento diseñado para evaluar el constructo impulsividad en tres dimensiones: atencional, motora y no planeada. La escala ha sido aplicada en pacientes con diferentes diagnósticos, en los cuales la sintomatología de impulsividad es característica. En Argentina no existen estudios que evalúen las propiedades psicométricas del instrumento en población clínica. El objetivo del trabajo fue evaluar las propiedades psicométricas de la escala en una muestra de la Ciudad de Buenos Aires. Se seleccionaron 150 sujetos adultos: 67 no presentaban diagnóstico psiquiátrico relevante, 56 cumplían criterios de trastorno bipolar y 27 presentaban diagnóstico de trastorno por déficit de atención. Se evaluaron la consistencia interna, la validez de constructo, la validez discriminativa y la estructura factorial. El alfa de Cronbach fue de 0,84 para la escala total. Asimismo, el instrumento ha demostrado indicadores aceptables de validez de constructo y validez discriminativa. Se encontraron diferencias al comparar la estructura factorial original con los resultados del presente estudio. Los resultados apoyan la utilidad de la escala en el contexto psiquiátrico, científico y clínico para evaluar el constructo de impulsividad. El puntaje total de la escala ha obtenido los indicadores más robustos de confiabilidad y validez.

A commentary on ERP investigation of study-test back- ground mismatch during face recognition in schizophrenia by Guillaume et al. (2012). Schizophr. Res. 134, 101–109.

La interocepción como censado del estado homeostático y visceral, ha sido recientemente postulada como requisito para la conciencia de estados emocionales corporales (Craig, 2009). Vías parasimpáticas y espinotalámicas que codifican esta información corporal tienen relevo en la corteza insular. Simultáneamente, han sido descriptas otras funciones insulares implicadas en procesos conscientes, como la intencionalidad, la toma de decisiones, la conciencia sensorio-motora, la percepción temporal, reconocer la imagen visual de uno mismo o percibir confiables a otros individuos (Craig, 2009; Ibanez, Gleichgerrcht, & Manes, 2010). Esta evidencia, sumada a resultados de estudios de lesión y neuroimágenes funcionales, sugiere que la corteza insular anterior (IA) sería la encargada de integrar señales multimodales cognitivas, emocionales y sociales para dirigir las conductas motivacionales que entrañan la supervivencia del individuo. En esta revisión analizamos el cúmulo de evidencia que involucran a la interocepción y al procesamiento insular integrativo en el surgimiento de estados emocionales conscientes, a través de estudios de lesiones y de técnicas de conectividad funcional en resonancia magnética funcional (RMF).

Previous research on semantic dementia (SD) has demonstrated a link between conceptual representations and ability on a range of ´non-semantic´ tasks, both verbal and nonverbal. In all cases, SD patients perform well on items that conform to the underlying statistical ´surface´ structure of the domain in question but poor performance on items that are atypical with respect to these statistics. For such items, there is a strong tendency for the patients´ erroneous responses to reflect the more typical pattern. To date, most research on this topic has been conducted with English-speaking patients, and where extended to non-English languages, directly comparable aspects of each language have been probed. In this study we tested the generalisation of this theory by probing performance on an aspect of Spanish with no analogue in English (grammatical gender). As predicted, Spanish SD patients provided the correct gender to high frequency words or where the phonology of the noun strongly predicted the gender. For low frequency, atypical nouns, however, the patients made many more errors (preferring the statistically typical gender). As expected, performance on nouns with atypical grammatical gender was strongly correlated with the degree of semantic impairment across the case-series of SD patients.

The results not only provide another example of the critical relationship between semantic memory and ´non-semantic´ cognition, but also indicate that this theoretical framework generalises to novel aspects of non-English languages – suggesting that the phenomenon is based on brain-general mechanisms.

Several case reports have linked solvent exposure to Parkinson disease (PD), but few studies have assessed associations with specific agents using an analytic epidemiologic design. We tested the hypothesis that exposure to specific solvents is associated with PD risk using a discordant twin pair design. METHODS: Ninety-nine twin pairs discordant for PD ascertained from the National Academy of Sciences/National Research Council World War II Veteran Twins Cohort were interviewed regarding lifetime occupations and hobbies using detailed job task-specific questionnaires. Exposures to 6 specific solvents selected a priori were estimated by expert raters unaware of case status. RESULTS: Ever exposure to trichloroethylene (TCE) was associated with significantly increased risk of PD (odds ratio [OR], 6.1; 95% confidence interval [CI] 1.2-33; p = 0.034), and exposure to perchloroethylene (PERC) and carbon tetrachloride (CCl(4) ) tended toward significance (respectively: OR, 10.5; 95% CI, 0.97-113; p = 0.053; OR, 2.3; 95% CI, 0.9-6.1; p = 0.088). Results were similar for estimates of exposure duration and cumulative lifetime exposure. INTERPRETATION: Exposure to specific solvents may increase risk of PD. TCE is the most common organic contaminant in groundwater, and PERC and CCl(4) are also ubiquitous in the environment. Our findings require replication in other populations with well-characterized exposures, but the potential public health implications are substantial.

Several lines of experimental evidence support an association between facial processing and social cognition, but no direct link between cortical markers of facial processing and complex cognitive processes has been reported until now. In the current study, we tested the hypothesis that cortical electrophysiological markers for the processing of facial emotion are associated with individual differences in executive and social cognition skills. We tested for correlations between the amplitude of event-related potentials (N170) in a dual valence task and participants’ scores on three neuropsychological assessments (general neuropsychology, executive functioning, and social cognition). N170 was modulated by the stimulus type (face versus word) and the valence of faces (positive versus negative). The neural source of N170 was estimated to be the fusiform gyrus. Robust correlations were found between neuropsychological markers and measures of facial processing. Social cognition skills (as measured by three tests: the Reading the Mind in the Eyes test, the Faux Pas test, and the Iowa Gambling Task) correlated with cortical measures of emotional discrimination. Executive functioning ability also correlated with the cortical discrimination of complex emotional stimuli. Our findings suggest that the cortical processing of facial emotional expression is associated with social cognition skills.