Mes: junio 2015

The goal of this study is to assess the role of membership and valence effects on errors performed in a racial implicit association test indexed by event-related potentials (ERPs). Non-indigenous participants performed an implicit association test (IAT) paradigm emphasizing the feedback of error due to misclassification of ingroup (non-indigenous) and outgroup (indigenous) faces as well as positive and negative words. As expected, participants responded to the compatible task with higher accuracy than to incompatible tasks. This is the first report demonstrating that IAT errors produce electrophysiological ERP modulation. Our results suggest that medial frontal negativity is modulated not only by IAT error of membership and valence classifications but also by IAT compatible and incompatible tasks. These results provide a basis for the future use of the misclassification error in the IAT recorded simultaneously with ERPs in other classic social psychology contexts.

To investigate the presence of apathy symptoms in adolescents and adults with ADHD as a behavioral manifestation of underlying motivational deficits and to determine whether apathy symptoms were associated with a specific neuropsychological profile. METHOD: A total of 38 ADHD participants (28 of the combined subtype [ADHD/C] and 10 of the inattentive subtype [ADHD/I]) and 30 healthy controls (Ctrl) were assessed on two measures of apathy administered to subjects and informants. As well, ADHD participants completed a comprehensive neuropsychological battery. RESULTS: ADHD participants presented elevated scores on measures of apathy relative to controls (ADHD/I > ADHD/C > Ctrl). Informant-based ratings of apathy correlated significantly with behavioral measures of inattention. Apathy measures correlated significantly with executive tests, working memory, verbal fluency, and general intellectual abilities, only in the inattentive sample. CONCLUSIONS: This study stresses the relevance of motivational deficits in adult ADHD as a significant clinical dimension closely linked to inattention and executive difficulties.

This article provides a classification of primary progressive aphasia (PPA) and its 3 main variants to improve the uniformity of case reporting and the reliability of research results. Criteria for the 3 variants of PPA–nonfluent/agrammatic, semantic, and logopenic–were developed by an international group of PPA investigators who convened on 3 occasions to operationalize earlier published clinical descriptions for PPA subtypes. Patients are first diagnosed with PPA and are then divided into clinical variants based on specific speech and language features characteristic of each subtype. Classification can then be further specified as «imaging-supported » if the expected pattern of atrophy is found and «with definite pathology » if pathologic or genetic data are available. The working recommendations are presented in lists of features, and suggested assessment tasks are also provided. These recommendations have been widely agreed upon by a large group of experts and should be used to ensure consistency of PPA classification in future studies. Future collaborations will collect prospective data to identify relationships between each of these syndromes and specific biomarkers for a more detailed understanding of clinicopathologic correlations.

The vegetative state (VS) is characterized by the absence of awareness of self or the environment and preserved autonomic functions. The diagnosis relies critically on the lack of consistent signs of purposeful behavior in response to external stimulation. Yet, given that patients with disorders of consciousness often exhibit fragmented movement patterns, voluntary actions may go unnoticed. Here we designed a simple motor paradigm that could potentially detect signs of purposeful behavior in VS patients with mild to severe brain damage by examining the neural correlates of motor preparation in response to verbal commands. Twenty-four patients who met the diagnostic criteria for VS were recruited for this study. Eleven of these patients showing preserved auditory evoked potentials underwent functional magnetic resonance imaging (fMRI) to test for basic speech processing. Five of these patients, who showed word related activity, were included in a second fMRI study aimed at detecting functional changes in premotor cortex elicited by specific verbal instructions to move either their left or their right hand. Despite the lack of overt muscle activity, two patients out of five activated the dorsal premotor cortex contralateral to the instructed hand, consistent with movement preparation. Our results may reflect residual voluntary processing in these two patients. We believe that the identification of positive results with fMRI using this simple task, may complement the clinical assessment by helping attain a more precise diagnosis in patients with disorders of consciousness.

The reported prevalence of asymptomatic atherosclerotic disease of the extracranial internal carotid artery is up to 12.5%. Carotid angioplasty has not yet proven safe and effective enough to prevent ischemic stroke in these patients. Randomized studies showed that carotid endarterectomy is superior to medical therapy in reducing the risk of ischemic stroke when performed by surgical teams with complication rates (stroke or death) of less than 3%. However, recruitment of these patients began more than 25 years ago, when the use of antiplatelet agents was lower than today, the treatment of hypertension was less effective than currently, and statins were not considered as key components of vascular prevention strategies. Optimizing the quality of medical treatment in recent decades has led to a significant reduction in stroke risk in patients not undergoing surgery. Based on these observations and with the exception of specific cases, medical therapy is the treatment of choice for patients with asymptomatic atherosclerotic disease of the extracranial carotid arteries.

The present study is the first to investigate the relationship between vagal tone level and event-related potentials (ERPs) in adults. Numerous studies have shown a relationship between vagal tone and the individual differences between a variety of psychophysiological, affective, and social outcomes. This suggests that vagal tone can be related to how people process relevant affective social information at the brain level. This study aimed to assess whether the ERP response varies between high and low vagal tone groups, in the face of salient affective information. In the experimental cohort, two groups were separated according to their vagal tone level. ERPs were recorded while individuals performed an affective picture task that included positive, neutral, and negative emotional stimuli. Differences between the high and low vagal tone groups were observed at the early posterior negativity for both positive and negative valences, and at the late positive potential for all the categories. It can be concluded that differences between high and low vagal tone levels are related to differences in the ERPs at early, middle, and late latencies. The results are discussed with respect to the effect of differences between the vagal tone conditions on various stages of information-processing.

The present study compares the occurrence of depressive symptoms evaluated by the Calgary Depression Scale for Schizophrenia (CDSS) in patients of Multiplex (MS) and Simplex Schizophrenia families (SS). The Positive and Negative Syndrome Scale (PANSS) was used to evaluate psychopathology. A total of 206 paranoid schizophrenia patients were studied according DSM-IV criteria. The Family Interview for Genetic Studies (FIGS) was used to study the families. A result in the FIGS for a positive family history of schizophrenia was referred as MS (patients); its lack as SS (patients). CDSS scores were compared among MS and SS patients and possible sex differences intra- and inter-groups were explored. In the analysis of our sample (30) 19% of the total persons with schizophrenia group was depressed. The depressive symptoms measured by the CDSS were higher in females and the MS males group. Males from MS group showed more depressive symptoms than males from SS group. No differences with females from both groups were found. Findings in this study underscore the importance of gender and family history in understanding the heterogeneity of schizophrenia. This study suggests that sex and familiar history are important to consider in studying depressive symptoms.

The major goal of evoked related potential studies arise in source localization techniques to identify the loci of neural activity that give rise to a particular voltage distribution measured on the surface of the scalp. In this paper we evaluate the effect of the head model adopted in order to estimate the N170 component source in attention deficit hyperactivity disorder (ADHD) patients and control subjects, considering faces and words stimuli. The standardized low resolution brain electromagnetic tomography algorithm (sLORETA) is used to compare between the three shell spherical head model and a fully realistic model based on the ICBM-152 atlas. We compare their variance on source estimation and analyze the impact on the N170 source localization. Results show that the often used three shell spherical model may lead to erroneous solutions, specially on ADHD patients, so its use is not recommended. Our results also suggest that N170 sources are mainly located in the right occipital fusiform gyrus for faces stimuli and in the left occipital fusiform gyrus for words stimuli, for both control subjects and ADHD patients. We also found a notable decrease on the N170 estimated source amplitude on ADHD patients, resulting in a plausible marker of the disease.

The lifespan of people with severe mental illness (SMI) is shorter compared to the general population. This excess mortality is mainly due to physical illness. We report prevalence rates of different physical illnesses as well as important individual lifestyle choices, side effects of psychotropic treatment and disparities in health care access, utilization and provision that contribute to these poor physical health outcomes. We searched MEDLINE (1966 – August 2010) combining the MeSH terms of schizophrenia, bipolar disorder and major depressive disorder with the different MeSH terms of general physical disease categories to select pertinent reviews and additional relevant studies through cross-referencing to identify prevalence figures and factors contributing to the excess morbidity and mortality rates. Nutritional and metabolic diseases, cardiovascular diseases, viral diseases, respiratory tract diseases, musculoskeletal diseases, sexual dysfunction, pregnancy complications, stomatognathic diseases, and possibly obesity-related cancers are, compared to the general population, more prevalent among people with SMI. It seems that lifestyle as well as treatment specific factors account for much of the increased risk for most of these physical diseases. Moreover, there is sufficient evidence that people with SMI are less likely to receive standard levels of care for most of these diseases. Lifestyle factors, relatively easy to measure, are barely considered for screening; baseline testing of numerous important physical parameters is insufficiently performed. Besides modifiable lifestyle factors and side effects of psychotropic medications, access to and quality of health care remains to be improved for individuals with SMI.

Diagnosis of behavioral variant frontotemporal dementia (bvFTD) can be especially challenging during the early stages for several reasons, including the fact that (a) behavioral disturbances in bvFTD can mimic the symptomatic profile of psychiatric disorders; (b) neuropsychological performance may be relatively spared; and (c) changes in structural neuroimaging may go undetected. Most frequently, bvFTD is not included as part of medical or residency training outside the field of cognitive neurology. The present study aimed at examining bvFTD-related practices concerning academic and professional training, diagnosis, and treatment across Latin America. We surveyed the academic and professional aspects of clinical practice related to bvFTD of 596 physicians from different fields throughout the continent. We discuss several aspects concerning Latin American physicians’ training on dementia and bvFTD, the way in which they approach the differential diagnosis of bvFTD, and their most frequent strategies for the treatment of this condition. We conclude that information about bvFTD deserves more attention in both undergraduate and postgraduate medical education in Latin America, and that understanding clinical practices related to FTD can help design more efficient training programs for physicians in this and other world regions.