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EXECUTIVE FUNCTIONS EVALUATION PERFORMED BY EVENT RELATED POTENTIALS INCHILDREN WITH OBSESSIVE-COMPULSIVE DISORDER  [PDF]
Tatjana ZORCEC,Nada POP-JORDANOVA
Journal of Special Education and Rehabilitation , 2011,
Abstract: Introduction: Obsessive-compulsive disorder [OCD] is characterized by repetitive, disturbing obsessions and/or compulsions. Obsessions are thoughts, images or feelings which are unwanted, persistent and recurrent. Compulsions are repetitive and ritual motor acts which are performed to decrease the anxiety level caused by repetitive obsessions. The onset of the OCD is typically during adolescence or early adulthood. Its prevalence among children is from 1% to 3% and it appears to be more present among boys than girls. Nowadays, the most effective way to treat OCD is to combine psychopharmacological with cognitive-behavioral treatment strategies. In the past decades researchers were more involved in investigating the role of the executive functions [EF] in psychiatric disorders.Aim of the study: to investigate EF among children with OCD by using Event Related Potentials (ERPs) on the Go/NoGo tasks. Subjects and methods: The sample is comprised of 20 children from both genders, between seven and 14 years of age [М=10,33±1,83], all diagnosed with OCD. Psychological evaluation was performed with Child Behavior Check List, Kohs cubes for assessment of the intellectual capacities, Beck Depression Inventory, The Schedule for Affective Disorders and Schizophrenia for School-Age Children, Stroop Color Word Test and Wisconsin Card Sorting Test. Neuropsychological evaluation was performed with the Visual Continuous Performance Test [VCPT] from which the Event Related Potentials [ERP] components were extracted.Results: There is a clear presence of obsessions and/or compulsions, absence of symptoms of depression, presence of perseverative errors and mild difficulties in mental flexibility. The ERP results cannot be understood as a disturbance of the EF in a direct sense, rather than as a disturbed normal functioning caused by the high anxiety level.Conclusion: There is no significant clinical manifestation of cognitive dysfunction among children with OCD in the early stage of the disorder, but it could be expected the same one to be appearing in the later stages of the disorder.
EXECUTIVE DYSFUNCTION IN OBSESSIVE - COMPULSIVE DISORDER AND THE TOURETTE SYNDROME
Amanda Menezes,Natália Martins Dias,Alessandra Gotuzo Seabra
Cuadernos de Neuropsicologia , 2011,
Abstract: Among the cognitive abilities more studied recently are the executive functions(EF), that are essential in the execution of new tasks and able the individual commitment in goal directed actions. Executive dysfunctions are recognized in diverse psychiatric conditions, including the Obsessive-compulsive Disorder (OCD) and the Tourette Syndrome (TS). This theoretical revision aimed to extend the knowledge about the relation between EF damages and these mentioned disorders. In the greater part, the scientific studies in the area have presented a near association between the EF damage, the OCD, and the TS. However, there are researches that refute these findings, showing that there is still not a determinant theory about this relationship. Beyond that, even among the researches that share the relation between EF, OCD, and TS, is not possible affirm which specific executive abilities are injured in each case. Then, the study concludes that, even with the increase of the number of researches carried out, many questionings persist about the EF damage in psychiatric disorders. These data reveal the need of more researches about the subject,what can improve considerably the quality of the diagnoses,prognostics and treatments carried out.
A mathematical model of reward and executive circuitry in obsessive compulsive disorde  [PDF]
Anca Radulescu,Rachel Marra
Quantitative Biology , 2015,
Abstract: The neuronal circuit that controls obsessive and compulsive behaviors involves a complex network of brain regions (some with known involvement in reward processing). Among these are cortical regions, the striatum and the thalamus (which compose the CSTC pathway), limbic areas such as the amygdala and the hippocampus, and well as dopamine pathways. Abnormal dynamic behavior in this brain network is a hallmark feature of patients with increased anxiety and motor activity, like the ones affected by OCD. There is currently no clear understanding of precisely what mechanisms generates these behaviors. We attempt to investigate a collection of connectivity hypotheses of OCD by means of a computational model of the brain circuitry that governs reward and motion execution. Mathematically, we use methods from ordinary differential equations and continuous time dynamical systems. We use classical analytical methods as well as computational approaches to study phenomena in the phase plane (e.g., behavior of the system's solutions when given certain initial conditions) and in the parameter space (e.g., sensitive dependence of initial conditions). We find that different obsessive-compulsive subtypes may correspond to different abnormalities in the network connectivity profiles. We suggest that it is combinations of parameters (connectivity strengths between regions), rather the than the value of any one parameter taken independently, that provides the best basis for predicting behavior, and for understanding the heterogeneity of the illness.
Movement related potentials in children and adolescents with obsessive compulsive disorder
Cengiz TATAROGLU,Fevziye TOROS
Journal of Neurological Sciences , 2003,
Abstract: There are strong evidences involving the abnormalities of basal ganglia and motor control in patients with obsessive-compulsive disorders (OCD). Movement-related potentials (MRP) reflect the activity of sensorimotor cortex and subcortical structures associated with movement preparation. Our aim was to investigate the MRPs in patients with OCD. We recorded MRPs from 20 patients with OCD. MRPs were obtained during simple (self-paced movement of right index finger) and more complex (simultanous movement of both index fingers) motor tasks. Early (N500 and N650) and late components (N1) of MRPs were analysed. Additionally, the onset latency of negativity (N0) was analysed. The results were compared with the data obtained from 14 healthy controls. The amplitudes of N500 and N650 were lower in patients with OCD than those obtained from controls but this difference did not reach statistical significance. Our findings show that MRPs preceding finger movement have failed in demonstration of alteration in cortical movement preparation in patients with OCD. MRPs can be analysed in further studies by using different motor tasks in patients with OCD.
The extended fronto-striatal model of obsessive compulsive disorder: convergence from event-related potentials, neuropsychology and neuroimaging  [PDF]
Margherita Melloni,Claudia Urbistondo,Lucas Sede?o,Carlos Gelormini,Rafael Kichic,Agustin Ibanez
Frontiers in Human Neuroscience , 2012, DOI: 10.3389/fnhum.2012.00259
Abstract: In this work, we explored convergent evidence supporting the fronto-striatal model of obsessive-compulsive disorder (FSMOCD) and the contribution of event-related potential (ERP) studies to this model. First, we considered minor modifications to the FSMOCD model based on neuroimaging and neuropsychological data. We noted the brain areas most affected in this disorder -anterior cingulate cortex (ACC), basal ganglia (BG), and orbito-frontal cortex (OFC) and their related cognitive functions, such as monitoring and inhibition. Then, we assessed the ERPs that are directly related to the FSMOCD, including the error-related negativity (ERN), N200, and P600. Several OCD studies present enhanced ERN and N2 responses during conflict tasks as well as an enhanced P600 during working memory (WM) tasks. Evidence from ERP studies (especially regarding ERN and N200 amplitude enhancement), neuroimaging and neuropsychological findings suggests abnormal activity in the OFC, ACC, and BG in OCD patients. Moreover, additional findings from these analyses suggest dorsolateral prefrontal and parietal cortex involvement, which might be related to executive function (EF) deficits. Thus, these convergent results suggest the existence of a self-monitoring imbalance involving inhibitory deficits and executive dysfunctions. OCD patients present an impaired ability to monitor, control, and inhibit intrusive thoughts, urges, feelings, and behaviors. In the current model, this imbalance is triggered by an excitatory role of the BG (associated with cognitive or motor actions without volitional control) and inhibitory activity of the OFC as well as excessive monitoring of the ACC to block excitatory impulses. This imbalance would interact with the reduced activation of the parietal-DLPC network, leading to executive dysfunction. ERP research may provide further insight regarding the temporal dynamics of action monitoring and executive functioning in OCD.
Brain Potentials of Conflict and Error-Likelihood Following Errorful and Errorless Learning in Obsessive-Compulsive Disorder  [PDF]
Anke Hammer, Andreas Kordon, Marcus Heldmann, Bartosz Zurowski, Thomas F. Münte
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0006553
Abstract: Background The anterior cingulate cortex (ACC) is thought to be overacting in patients with Obsessive Compulsive Disorder (OCD) reflecting an enhanced action monitoring system. However, influences of conflict and error-likelihood have not been explored. Here, the error-related negativity (ERN) originating in ACC served as a measure of conflict and error-likelihood during memory recognition following different learning modes. Errorless learning prevents the generation of false memory candidates and has been shown to be superior to trial-and-error-learning. The latter, errorful learning, introduces false memory candidates which interfere with correct information in later recognition leading to enhanced conflict processing. Methodology/Principal Findings Sixteen OCD patients according to DSM-IV criteria and 16 closely matched healthy controls participated voluntarily in the event-related potential study. Both, OCD- and control group showed enhanced memory performance following errorless compared to errorful learning. Nevertheless, response-locked data showed clear modulations of the ERN amplitude. OCD patients compared to controls showed an increased error-likelihood effect after errorless learning. However, with increased conflict after errorful learning, OCD patients showed a reduced error-likelihood effect in contrast to controls who showed an increase. Conclusion/Significance The increase of the errorlikelihood effect for OCD patients within low conflict situations (recognition after errorless learning) might be conceptualized as a hyperactive monitoring system. However, within high conflict situations (recognition after EF-learning) the opposite effect was observed: whereas the control group showed an increased error-likelihood effect, the OCD group showed a reduction of the error-likelihood effect based on altered ACC learning rates in response to errors. These findings support theoretical frameworks explaining differences in ACC activity on the basis of conflict and perceived error-likelihood as influenced by individual error learning rate.
Cortical Potentials Evoked by Deep Brain Stimulation in the Subthalamic Area  [PDF]
Annaelle Devergnas,Thomas Wichmann
Frontiers in Systems Neuroscience , 2011, DOI: 10.3389/fnsys.2011.00030
Abstract: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been used since the mid-1990s as a treatment for patients with Parkinson’s disease, and more recently also in other conditions, such as dystonia or obsessive compulsive disorder. Non-invasive studies of cortical evoked potentials (EPs) that follow individual STN–DBS stimuli has provided us with insights about the conduction of the DBS pulses to the cortex. Such EPs have multiple components of different latencies, making it possible to distinguish short-latency and long-latency responses (3–8 ms and 18–25 ms latency, respectively). The available evidence indicates that these short- and long-latency EPs correspond to conduction from the STN stimulation site to the cortical recording location via anti- and orthodromic pathways, respectively. In this review we survey the literature from recording studies in human patients treated with STN–DBS for Parkinson’s disease and other conditions, as well as recent animal studies (including our own) that have begun to elucidate details of the pathways, frequency dependencies, and other features of EPs. In addition, we comment on the possible clinical utility of this knowledge.
Childhood-Onset Obsessive Compulsive Disorder  [PDF]
Dursun Karaman,Ibrahim Durukan,Murat Erdem
Psikiyatride Guncel Yaklasimlar , 2011,
Abstract: Childhood-onset obsessive-compulsive disorder affects 1%-2% of children and adolescents. While symptoms reported by children and behavioral therapies and pharmacological interventions administered to children are similar to those seen among individuals who develop obsessive compulsive disorder in adulthood, there are several differences with regards to sex ratios, comorbidity patterns, neuroimaging findings. Family and twin studies support the role of genetics in some forms of obsessive compulsive disorder. Prefrontal cortex, cingulate cortex, thalamus, nucleus caudatus, putamen and globus pallidus are the main brain areas affected in children with obsessive compulsive disorder. Selective serotonin reuptake inhibitors (SSRI) are the treatment of choice for pharmacotherapy of obsessive compulsive disorder and exposure and response prevention are the most commonly applied behavioral therapy methods in obsessive compulsive disorder. Despite advances in the treatment of the disorder, obsessive compulsive disorder is still considered as a debilitating chronic disorder.
Metacognitive Model of Obsessive Compulsive Disorder  [PDF]
Omer Senormanci,Ramazan Konkan,Oya Gonullu Guclu,Mehmet Zihni Sungur
Psikiyatride Guncel Yaklasimlar , 2012,
Abstract: Several authors have suggested that not only appraisal of significance of external events and signals from the body, but also appraisal of the personal significance of thoughts are important, and emphasized the conceptual limitations of the schema approach in cognitive model and developed the integrative information processing model of emotional disorders. According to this approach, the assessment of the meaning of thought, rather than thought itself is more important in the development and maintenance of the psychopathology. In the metacognitive model of obsessive compulsive disorder, three types of metacognitive beliefs are emphasized. These are; thought-action fusion (thought-action, thought-event, thought-object), metacognitive beliefs on performing the rituals and metacognitive beliefs on the warning to stop to terminate the rituals. According to the model, targeting directly to change in metacognitive beliefs will increase success in therapy. In this article, the concept of metacognition in emotional disorders, the metacognitive model of obsessive compulsive disorder and the advances that the model introduced in conceptualization and treatment of obsessive compulsive disorder have been discussed.
Obsessive compulsive disorder with pervasive avoidance  [cached]
Sharma Parul,Sharma Ravi,Kumar Ramesh,Sharma Dinesh
Indian Journal of Psychological Medicine , 2009,
Abstract: Obsessive compulsive disorder (OCD) is a common disorder, but some of its atypical presentations are uncommon and difficult to diagnose. We report one such case which on initial presentation appeared to be psychotic protocol but after detailed workup was diagnosed as OCD with marked avoidance symptoms.
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