Categoría: Papers con abstracts

BACKGROUND: A growing body of evidence suggests that patients with bipolar disorder (BD) have cognitive impairments even during euthymic periods. The main cognitive domains affected are verbal memory, attention, and executive function. Nevertheless, some studies suggest that at least a subgroup of euthymic patients demonstrates intact executive functioning in classic neuropsychological tests, which could be due to the lack of real-life, or ecological validity. OBJECTIVE: In this study, we highlight the usefulness of incorporating more ecological tests of executive function in assessment batteries in order to detect specific cognitive deficits in BD patients with otherwise normal performance in standard executive tests. METHODS: Nineteen euthymic BD patients and 15 healthy controls completed a standard neuropsychological battery assessment and two experimental tasks (the Multiple Errands Test-Hospital Version and the Hotel Task) to measure executive functioning in highly demanding cognitive settings that mimic real-life scenarios. RESULTS: No significant differences were found between the groups’ demographic variables. We found, as predicted, that the group of euthymic BD patients who had control-comparable performance in classic executive tasks showed important deficits in more ecological tasks of executive functioning of the type that mimic real-life scenarios. CONCLUSIONS: Together, these data suggest that the inclusion of ecological tests in the assessment of BD patients can contribute to providing a more realistic cognitive profile of this patient population, which will undoubtedly allow for a better design of therapeutic and rehabilitation strategies that can help patients to minimize impact in real-life settings.

BACKGROUND: Adults with bipolar disorder (BD) have cognitive impairments that affect face processing and social cognition. However, it remains unknown whether these deficits in euthymic BD have impaired brain markers of emotional processing. METHODOLOGY/PRINCIPAL FINDINGS: We recruited twenty six participants, 13 controls subjects with an equal number of euthymic BD participants. We used an event-related potential (ERP) assessment of a dual valence task (DVT), in which faces (angry and happy), words (pleasant and unpleasant), and face-word simultaneous combinations are presented to test the effects of the stimulus type (face vs word) and valence (positive vs. negative). All participants received clinical, neuropsychological and social cognition evaluations. ERP analysis revealed that both groups showed N170 modulation of stimulus type effects (face > word). BD patients exhibited reduced and enhanced N170 to facial and semantic valence, respectively. The neural source estimation of N170 was a posterior section of the fusiform gyrus (FG), including the face fusiform area (FFA). Neural generators of N170 for faces (FG and FFA) were reduced in BD. In these patients, N170 modulation was associated with social cognition (theory of mind). CONCLUSIONS/SIGNIFICANCE: This is the first report of euthymic BD exhibiting abnormal N170 emotional discrimination associated with theory of mind impairments.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) share DSM-IV criteria in adults and cause problems in decision-making. Nevertheless, no previous report has assessed a decision-making task that includes the examination of the neural correlates of reward and gambling in adults with ADHD and those with BD. METHODOLOGY/PRINCIPAL FINDINGS: We used the Iowa gambling task (IGT), a task of rational decision-making under risk (RDMUR) and a rapid-decision gambling task (RDGT) which elicits behavioral measures as well as event-related potentials (ERPs: fERN and P3) in connection to the motivational impact of events. We did not observe between-group differences for decision-making under risk or ambiguity (RDMUR and IGT); however, there were significant differences for the ERP-assessed RDGT. Compared to controls, the ADHD group showed a pattern of impaired learning by feedback (fERN) and insensitivity to reward magnitude (P3). This ERP pattern (fERN and P3) was associated with impulsivity, hyperactivity, executive function and working memory. Compared to controls, the BD group showed fERN- and P3-enhanced responses to reward magnitude regardless of valence. This ERP pattern (fERN and P3) was associated with mood and inhibitory control. Consistent with the ERP findings, an analysis of source location revealed reduced responses of the cingulate cortex to the valence and magnitude of rewards in patients with ADHD and BD. CONCLUSIONS/SIGNIFICANCE: Our data suggest that neurophysiological (ERPs) paradigms such as the RDGT are well suited to assess subclinical decision-making processes in patients with ADHD and BD as well as for linking the cingulate cortex with action monitoring systems.

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 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 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 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.

Pathological Gambling in a Bipolar Patient treated with Pramipexole. Autores Strejilevich S, Martino D, Igoa A, Manes F. Año 2011 Journal  Strejilevich S, Martino D, Igoa A, Manes F. Volumen 23(1): E2-E3 Abstract   Otra información    

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 emerging impact of social neuroscience on neuropsychiatry and clinical neuroscience. Autores Mendez MF, Manes F.  Año 2011 Journal  Mendez MF, Manes F.  Volumen 6(5-6): 415-419 Abstract   Otra información