Mes: junio 2015

Current research on empathy for pain emphasizes the overlap in the neural response between the first-hand experience of pain and its perception in others. However, recent studies suggest that the perception of the pain of others may reflect the processing of a threat or negative arousal rather than an automatic pro-social response. It can thus be suggested that pain processing of other-related, but not self-related, information could imply danger rather than empathy, due to the possible threat represented in the expressions of others (especially if associated with pain stimuli). To test this hypothesis, two experiments considering subliminal stimuli were designed. In Experiment 1, neutral and semantic pain expressions previously primed with own or other faces were presented to participants. When other-face priming was used, only the detection of semantic pain expressions was facilitated. In Experiment 2, pictures with pain and neutral scenarios previously used in ERP and fMRI research were used in a categorization task. Those pictures were primed with own or other faces following the same procedure as in Experiment 1 while ERPs were recorded. Early (N1) and late (P3) cortical responses between pain and no-pain were modulated only in the other-face priming condition. These results support the threat value of pain hypothesis and suggest the necessity for the inclusion of own- versus other-related information in future empathy for pain research.

Based on the recent literature and collective experience, an international consortium developed revised guidelines for the diagnosis of behavioural variant frontotemporal dementia. The validation process retrospectively reviewed clinical records and compared the sensitivity of proposed and earlier criteria in a multi-site sample of patients with pathologically verified frontotemporal lobar degeneration. According to the revised criteria, ‘possible’ behavioural variant frontotemporal dementia requires three of six clinically discriminating features (disinhibition, apathy/inertia, loss of sympathy/empathy, perseverative/compulsive behaviours, hyperorality and dysexecutive neuropsychological profile). ‘Probable’ behavioural variant frontotemporal dementia adds functional disability and characteristic neuroimaging, while behavioural variant frontotemporal dementia ‘with definite frontotemporal lobar degeneration’ requires histopathological confirmation or a pathogenic mutation. Sixteen brain banks contributed cases meeting histopathological criteria for frontotemporal lobar degeneration and a clinical diagnosis of behavioural variant frontotemporal dementia, Alzheimer’s disease, dementia with Lewy bodies or vascular dementia at presentation. Cases with predominant primary progressive aphasia or extra-pyramidal syndromes were excluded. In these autopsy-confirmed cases, an experienced neurologist or psychiatrist ascertained clinical features necessary for making a diagnosis according to previous and proposed criteria at presentation. Of 137 cases where features were available for both proposed and previously established criteria, 118 (86%) met ‘possible’ criteria, and 104 (76%) met criteria for ‘probable’ behavioural variant frontotemporal dementia. In contrast, 72 cases (53%) met previously established criteria for the syndrome (P < 0.001 for comparison with 'possible' and 'probable' criteria). Patients who failed to meet revised criteria were significantly older and most had atypical presentations with marked memory impairment. In conclusion, the revised criteria for behavioural variant frontotemporal dementia improve diagnostic accuracy compared with previously established criteria in a sample with known frontotemporal lobar degeneration. Greater sensitivity of the proposed criteria may reflect the optimized diagnostic features, less restrictive exclusion features and a flexible structure that accommodates different initial clinical presentations. Future studies will be needed to establish the reliability and specificity of these revised diagnostic guidelines.

BACKGROUND: The behavioral variant of frontotemporal dementia (bvFTD) is characterized by progressive changes in personality and social interaction, loss of empathy, disinhibition and impulsivity, most of which generally precede the onset of cognitive deficits. In this study, we investigated decision-making cognition in a group of patients with an early bvFTD diagnosis whose standard neuropsychological performance was within normal range for all variables. METHODS: The Iowa Gambling Task was administered to this group of early bvFTD patients, to a group of early bvFTD patients who had shown impaired performance on the classical neuropsychological battery and to healthy controls. RESULTS: Decision-making was impaired in both bvFTD patient groups, whether they had shown impaired or normal performance in the classical neuropsychological evaluation. CONCLUSIONS: Patients with early bvFTD may perform normally on standard cognitive tests, and yet develop severe deficits in judgment and decision-making. In many current legal systems, early bvFTD patients showing preserved cognitive functioning who commit unlawful acts run the risk of not being able to plead insane or not guilty on the grounds of diminished responsibility beyond reasonable doubt. This represents a unique legal and ethical dilemma. Our findings have important implications for medicolegal decisions relating to capacity and culpability, and regarding the philosophical concept of ‘free will’.

BACKGROUND: The Addenbrooke’s Cognitive Examination Revised (ACE-R) is an improved version of the earlier brief screening test which has been validated in English with high sensitivity and specificity to detect cognitive dysfunction. The aim of this study was to validate the Spanish version of the ACE-R in an Argentine population. METHODS: A group of patients with Alzheimer Disease (AD) and patients with behavioural variant Frontotemporal Dementia (bvFTD) paired by age, sex, and years of education with healthy controls were assessed using the ACE-R. Stage of dementia was measured with the Clinical Dementia Rating Scale (CDR). The English version of the ACE-R was first translated into Spanish and then back-translated into English by two blind independent experts. RESULTS: Internal reliability was very good (Cronbach’s alpha=0.89). Concurrent validity, determined by the correlation between total ACE-R and CDR was significant (P<.001) and inter-rater reliability was excellent (Cohen's kappa=0.98). Controls significantly outperformed AD and bvFTD patients on most subdomains of the ACE-R, with significant differences between the dementia groups. With a cut-off score of 85 points, sensitivity was 97.5% and specificity was 88.5%, with a likelihood ratio of 99.3 for the detection of dementia. The ACE-R showed higher sensitivity than the MMSE for the detection of dementia. CONCLUSIONS: The Spanish version of the ACE-R is a brief yet reliable screening tool for the detection of early cognitive impairment and has shown to discriminate between bvFTD and AD.

BACKGROUND: Most of the empirical studies that support the efficacy of prolonged exposure (PE) for treating posttraumatic stress disorder (PTSD) have been conducted on white mainstream English-speaking populations. Although high PTSD rates have been reported for Puerto Ricans, the appropriateness of PE for this population remains unclear. The purpose of this study was to examine the feasibility of providing PE to Spanish speaking Puerto Ricans with PTSD. Particular attention was also focused on identifying challenges faced by clinicians with limited experience in PE. This information is relevant to help inform practice implications for training Spanish-speaking clinicians in PE. RESULTS: Fourteen patients with PTSD were randomly assigned to receive PE (n = 7) or usual care (UC) (n = 7). PE therapy consisted of 15 weekly sessions focused on gradually confronting and emotionally processing distressing trauma-related memories and reminders. Five patients completed PE treatment; all patients attended the 15 sessions available to them. In UC, patients received mental health services available within the health care setting where they were recruited. They also had the option of self-referring to a mental health provider outside the study setting. The Clinician-Administered PTSD Scale (CAPS) was administered at baseline, mid-treatment, and post-treatment to assess PTSD symptom severity. Treatment completers in the PE group demonstrated significantly greater reductions in PTSD symptoms than the UC group. Forty percent of the PE patients showed clinically meaningful reductions in PTSD symptoms from pre- to post-treatment. CONCLUSIONS: PE appears to be viable for treating Puerto Rican Spanish-speaking patients with PTSD. This therapy had good patient acceptability and led to improvements in PTSD symptoms. Attention to the clinicians’ training process contributed strongly to helping them overcome the challenges posed by the intervention and increased their acceptance of PE.

BACKGROUND: Mitochondrial dysfunction and oxidative stress are pathophysiologic mechanisms implicated in experimental models and genetic forms of Parkinson’s disease (PD). Certain pesticides may affect these mechanisms, but no pesticide has been definitively associated with PD in humans. OBJECTIVES: Our goal was to determine whether pesticides that cause mitochondrial dysfunction or oxidative stress are associated with PD or clinical features of parkinsonism in humans. METHODS: We assessed lifetime use of pesticides selected by mechanism in a case-control study nested in the Agricultural Health Study (AHS). PD was diagnosed by movement disorders specialists. Controls were a stratified random sample of all AHS participants frequency-matched to cases by age, sex, and state at approximately three controls:one case. RESULTS: In 110 PD cases and 358 controls, PD was associated with use of a group of pesticides that inhibit mitochondrial complex I [odds ratio (OR)=1.7; 95% confidence interval (CI), 1.0-2.8] including rotenone (OR=2.5; 95% CI, 1.3-4.7) and with use of a group of pesticides that cause oxidative stress (OR = 2.0; 95% CI, 1.2-3.6), including paraquat (OR=2.5; 95% CI, 1.4-4.7). CONCLUSIONS: PD was positively associated with two groups of pesticides defined by mechanisms implicated experimentally-those that impair mitochondrial function and those that increase oxidative stress-supporting a role for these mechanisms in PD pathophysiology.

BACKGROUND: Integration of compatible or incompatible emotional valence and semantic information is an essential aspect of complex social interactions. A modified version of the Implicit Association Test (IAT) called Dual Valence Association Task (DVAT) was designed in order to measure conflict resolution processing from compatibility/incompatibly of semantic and facial valence. The DVAT involves two emotional valence evaluative tasks which elicits two forms of emotional compatible/incompatible associations (facial and semantic). METHODS: Behavioural measures and Event Related Potentials were recorded while participants performed the DVAT. RESULTS: Behavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli) showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT. CONCLUSIONS: Results suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli.

BACKGROUND: Information regarding predisposing factors, frequency, and prognostic implications of new onset atrial fibrillation (NOAF) after carotid endarterectomy (CEA) is scarce. We assessed the frequency, risk factors, and the prognostic impact of NOAF after CEA. METHODS: We assessed every patient undergoing CEA (n = 186) at our academic hospital between 2006 and 2009. Patients underwent continuous electrocardiographic monitoring during surgery and during the rest of hospital stay. We performed univariate and multivariate analyses for identifying variables associated with NOAF and for individualizing variables related to four perioperative adverse outcome measures: a) ischemic stroke; b) ischemic stroke and myocardial infarction, c) ischemic stroke and death, and d) ischemic stroke, myocardial infarction, and death. RESULTS: The study cohort comprised 186 patients. Overall, NOAF was detected in 7 cases (3.8%). The only variable associated with NOAF was intraoperative hypotension (OR 9.6, 95% CI 1.9-47.4, P = .006). There were no perioperative deaths. NOAF was associated with perioperative ischemic stroke and with the combined outcome of ischemic stroke and myocardial infarction. CONCLUSIONS: We found a low frequency of NOAF after CEA. Intraoperative hypotension was associated to a higher risk of NOAF. In turn, NOAF was related to adverse postoperative outcome. Further research is needed to clarify the pathophysiological relation between intraoperative hypotension, NOAF, and adverse CEA outcome.

El trastorno obsesivo-compulsivo es un trastorno psiquiátrico que en un 87% de los casos se vuelve crónico. Se caracteriza por una serie de síntomas que pueden ser agrupados en obsesiones y compulsiones, que pueden llegar a ser altamente invalidantes y afectar el estilo de vida de quienes lo padecen. Es importante entender los mecanismos neurológicos del trastorno obsesivo-compulsivo para poder abordar de manera más eficaz los tratamientos. Este trabajo plantea al modelo frontoestriado como aquel que provee mayor evidencia y explica de manera más acabada los fenómenos neuropsicológicos del TOC, con las áreas cerebrales que se encuentran implicadas en él córtex cingulado anterior, los ganglios basales, y la corteza órbito-frontal. Luego, se vinculan estos resultados con aquellos hallazgos de estudios de potenciales evocados relacionados a eventos (especialmente ERN, N200 y P300) con el fin de explicar más íntegramente lascaracterísticas del trastorno. Las funciones cognitivas que se pueden vincular con loshallazgos de neuroimágenes y ERPs son relativas al procesamiento de la información,decodificación, planificación, atención voluntaria, control inhibitorio, y funcionesejecutivas en general.

Employment is an indicator of socioeconomic status. Unemployment is a worldwide social challenge, especially in emerging countries, accounting for a proportion of the overall higher mortality rates found in these nations. We assessed the relationship between employment status and in-hospital mortality among acute ischemic stroke patients participating in the Argentinean National Stroke Registry (ReNACer), a prospective, country-wide, hospital-based stroke registry aimed at improving quality of stroke care in Argentina. We compared demographic and socioeconomic characteristics, risk factors, acute treatment, and stroke severity between employed and unemployed patients with acute ischemic stroke participating in ReNACer. We developed a multiple logistic regression model to identify predictors of in-hospital mortality. Among the 726 patients with acute ischemic stroke included in the study, 39.5% were unemployed. In-hospital mortality was higher in the patients who were unemployed at the time of the stroke compared with those who were employed (12.0% vs 5.0%; P = .003). On multivariate analysis, being unemployed (odds ratio [OR], 3.58; 95% confidence interval [CI], 1.36-7.37; P = .005), stroke severity (OR, 3.54; 95% CI 1.11-10.40; P = .018), and infarct size >15 mm (OR, 2.80; 95% CI, 1.18-6.60; P = .019) were associated with in-hospital mortality after adjusting for relevant covariates. Social factors may influence poor outcomes after stroke. In the present study, unemployment was associated with a higher risk of adjusted in-hospital mortality. Strategies targeting individuals at high risk of cardiovascular diseases and poorer outcomes should be implemented to reduce stroke impact.