887 resultados para schizophrenia
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Clinical decision support systems are useful tools for assisting physicians to diagnose complex illnesses. Schizophrenia is a complex, heterogeneous and incapacitating mental disorder that should be detected as early as possible to avoid a most serious outcome. These artificial intelligence systems might be useful in the early detection of schizophrenia disorder. The objective of the present study was to describe the development of such a clinical decision support system for the diagnosis of schizophrenia spectrum disorders (SADDESQ). The development of this system is described in four stages: knowledge acquisition, knowledge organization, the development of a computer-assisted model, and the evaluation of the system's performance. The knowledge was extracted from an expert through open interviews. These interviews aimed to explore the expert's diagnostic decision-making process for the diagnosis of schizophrenia. A graph methodology was employed to identify the elements involved in the reasoning process. Knowledge was first organized and modeled by means of algorithms and then transferred to a computational model created by the covering approach. The performance assessment involved the comparison of the diagnoses of 38 clinical vignettes between an expert and the SADDESQ. The results showed a relatively low rate of misclassification (18-34%) and a good performance by SADDESQ in the diagnosis of schizophrenia, with an accuracy of 66-82%. The accuracy was higher when schizophreniform disorder was considered as the presence of schizophrenia disorder. Although these results are preliminary, the SADDESQ has exhibited a satisfactory performance, which needs to be further evaluated within a clinical setting.
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The adaptive behavior of human beings is usually supported by rapid monitoring of outstanding events in the environment. Some investigators have suggested that a primary attention deficit might trigger symptoms of schizophrenia. In addition, researchers have long discussed the relationship between schizophrenia and the schizophrenia-like psychosis of epilepsy (SLPE). On the basis of these considerations, the objective of the present study was to investigate attention performance of patients with both disorders. Patient age was 18 to 60 years, and all patients had received formal schooling for at least four years. Patients were excluded if they had any systemic disease with neurologic or psychiatric comorbidity, or a history of brain surgery. The computer-assisted TAVIS-2R test was applied to all patients and to a control group to evaluate and discriminate between selective, alternating and sustained attention. The TAVIS-2R test is divided into three parts: one for selective attention (5 min), the second for alternating attention (5 min), and the third for the evaluation of vigilance or sustained attention (10 min). The same computer software was used for statistical analysis of reaction time, omission errors, and commission errors. The sample consisted of 36 patients with schizophrenia, 28 with interictal SLPE, and 47 healthy controls. The results of the selective attention tests for both patient groups were significantly lower than that for controls. The patients with schizophrenia and SLPE performed differently in the alternating and sustained attention tests: patients with SLPE had alternating attention deficits, whereas patients with schizophrenia showed deficits in sustained attention. These quantitative results confirmed the qualitative clinical observations for both patient groups, that is, that patients with schizophrenia had difficulties in focusing attention, whereas those with epilepsy showed perseveration in attention focus.
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The aim of the present study was to determine whether specific subgroups of schizophrenic patients, grouped according to electrodermal characteristics, show differences in the N-acetylaspartate/creatine plus choline (NAA / (Cr + Cho)) ratios in the frontal, cingulate and perirolandic cortices. Skin conductance levels (SCL) and skin conductance responses to auditory stimulation were measured in 38 patients with schizophrenia and in the same number of matched healthy volunteers (control). All subjects were submitted to multivoxel proton magnetic resonance spectroscopic imaging. When compared to the control group, patients presented significantly lower NAA / (Cr + Cho) ratios in the right dorsolateral prefrontal cortex (schizophrenia = 0.95 0.03; control = 1.12 0.04) and in the right (schizophrenia = 0.88 0.02; control = 0.94 0.03) and left (schizophrenia = 0.84 0.03; control = 0.94 0.03) cingulates. These ratios did not differ between electrodermally responsive and non-responsive patients. When patients were divided into two groups: lower SCL (less than the mean SCL of the control group minus two standard deviations) and normal SCL (similar to the control group), the subgroup with a lower level of SCL showed a lower NAA / (Cr + Cho) ratio in the left cingulate (0.78 0.05) than the controls (0.95 0.02, P < 0.05) and the subgroup with normal SCL (0.88 0.03, P < 0.05). There was a negative correlation between the NAA / (Cr + Cho) ratio in the left cingulate of patients with schizophrenia and the duration of the disease and years under medication. These data suggest the existence of a schizophrenic subgroup characterized by low SCL that could be a consequence of the lower neuronal viability observed in the left cingulate of these patients.
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Growing consistent evidence indicates that hypofunction of N-methyl-D-aspartate (NMDA) transmission plays a pivotal role in the neuropathophysiology of schizophrenia. Hence, drugs which modulate NMDA neurotransmission are promising approaches to the treatment of schizophrenia. The aim of this article is to review clinical trials with novel compounds acting on the NMDA receptor (NMDA-R). This review also includes a discussion and translation of neuroscience into schizophrenia therapeutics. Although the precise mechanism of action of minocycline in the brain remains unclear, there is evidence that it blocks the neurotoxicity of NMDA antagonists and may exert a differential effect on NMDA signaling pathways. We, therefore, hypothesize that the effects of minocycline on the brain may be partially modulated by the NMDA-R or related mechanisms. Thus, we have included a review of minocycline neuroscience. The search was performed in the PubMed, Web of Science, SciELO, and Lilacs databases. The results of glycine and D-cycloserine trials were conflicting regarding effectiveness on the negative and cognitive symptoms of schizophrenia. D-serine and D-alanine showed a potential effect on negative symptoms and on cognitive deficits. Sarcosine data indicated a considerable improvement as adjunctive therapy. Finally, minocycline add-on treatment appears to be effective on a broad range of psychopathology in patients with schizophrenia. The differential modulation of NMDA-R neurosystems, in particular synaptic versus extrasynaptic NMDA-R activation and specific subtypes of NMDA-R, may be the key mediators of neurogenesis and neuroprotection. Thus, psychotropics modulating NMDA-R neurotransmission may represent future monotherapy or add-on treatment strategies in the treatment of schizophrenia.
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Prenatal immune challenge (PIC) in pregnant rodents produces offspring with abnormalities in behavior, histology, and gene expression that are reminiscent of schizophrenia and autism. Based on this, the goal of this article was to review the main contributions of PIC models, especially the one using the viral-mimetic particle polyriboinosinic-polyribocytidylic acid (poly-I:C), to the understanding of the etiology, biological basis and treatment of schizophrenia. This systematic review consisted of a search of available web databases (PubMed, SciELO, LILACS, PsycINFO, and ISI Web of Knowledge) for original studies published in the last 10 years (May 2001 to October 2011) concerning animal models of PIC, focusing on those using poly-I:C. The results showed that the PIC model with poly-I:C is able to mimic the prodrome and both the positive and negative/cognitive dimensions of schizophrenia, depending on the specific gestation time window of the immune challenge. The model resembles the neurobiology and etiology of schizophrenia and has good predictive value. In conclusion, this model is a robust tool for the identification of novel molecular targets during prenatal life, adolescence and adulthood that might contribute to the development of preventive and/or treatment strategies (targeting specific symptoms, i.e., positive or negative/cognitive) for this devastating mental disorder, also presenting biosafety as compared to viral infection models. One limitation of this model is the incapacity to model the full spectrum of immune responses normally induced by viral exposure.
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The purpose of this study was to assess the efficacy of the Process Specific Approach to cognitive rehabilitation for a client with schizophrenia who has attentional deficits. The study was a single case experimental design which followed a variation of the multiple baseline approach. Prior to training of the attentional deficit, multiple baseline assessments were completed. These included an ov:erview of the sUbject's information processing ability, random measures of attention and a genera.l level of functioning in living, learning and working environments. During the re-training, attention tests were administered at the completion of each attention component. A general functional evaluation through interviews and a measure of information processing ability were. completed after the re-training was concluded. The results of the study demonstrate a significant i'mprovement in attention and memory measures. Qualitative data indicate signi.ficant others observed improvements in performance in r livi'ng, learning and working environments. The results suggest this approach to cognitive rehabilitation was effective with this subject and further research to establish generalizability is recommended.
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This study examined the commonalities and the differences between creativity and the schizophrenia spectrum. The variables measured as potential commonalities and differences were creativity, schizotypy, cognitive inhibition, spatial ability, balancing skills, positive and negative presence, absorption, mystical experiences, childhood abuse, and neuroticism. Three community groups were recruited, consisting of 31 artists, 10 people with schizophrenia, and 31 comparisons matched for gender and age with the artists. A larger student group consisting of 102 students was also recruited in order to examine the correlations among the same variables within a larger, more normative, group. The largest commonality between the artist and the schizophrenic groups, who represented the extreme end of the schizophrenia spectrum, was the propensity to mystical experiences. The greatest differences between the artist and the schizophrenic groups were that the artists were higher in creativity, performed better on spatial abilities, had better balance, had more positive states of presence, and were lower in neuroticism than the schizophrenic group. In the student group, creativity was correlated with spatial ability, positive presence, absorption, and mystical experiences. In addition, creativity was significantly related to two facets of schizotypy, unusual experiences and impulsive nonconformity. In other words, students high in certain facets of schizotypy, who may share certain characteristics with those who have schizophrenia, are higher in creativity, but people who are on the extreme end of the schizophrenia spectrum, who have been diagnosed with schizophrenia, are not. The differences between the artist and schizophrenic groups on spatial ability, balance, sense of presence, and neuroticism may help to determine whether mystical experiences help to integrate creative work or destabilize and disorganize the sense of self. It may be that mystical experiences can be used more positively by the creative individuals than people with schizophrenia, in that artists and people high in creativity were higher in positive traits such as positive presence and lower on negative variables such as neuroticism, and introvertive anhedonia.
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The purpose of this research is to expose and complicate those discourses of childhood imagination as demonstrated in the diagnostic criteria for early onset schizophrenia by using an antipsychiatry perspective. This will be done by evaluating those discourses alongside those found in popular childrens literature, specifically, Harry Potter and The Philosophers Stone, Bridge to Terabithia, and A Wrinkle in Time. Once uncovered, the underlying power discourses were then exposed. This research will then employ a minor reading as provided by Deleuze and Guattaris (1987) approach to minor literature to demonstrate the ways in which the child can subvert those dominant discourses. The potential of literature is evaluated for its ability to provide alternative modes of experience and lines of flight for the child subjected to the diagnostic criteria of schizophrenia.
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Contexte Autant dans une population schizophrne que non schizophrne, labus de substance a pour consquence la manifestation de symptmes psychiatriques et neurologiques. Dans les prsentes tudes cas-tmoins, nous avons examin les diffrences initiales ainsi que les changements suite au traitement de 12 semaines la quetiapine au niveau de la svrit de la toxicomanie et des symptmes psychiatriques et neurologiques chez 3 groupes distincts. Ces 3 groupes sont: des patients schizophrnes avec une toxicomanie (double diagnostic: DD), des patients schizophrnes sans toxicomanie concomittante (SCZ) et finalement, des toxicomanes non schizophrnes (SUD). Paralllement, afin de nous aider interprter nos rsultats, nous avons men deux revues systmatiques: la premire regardait leffet dantipsychotiques dans le traitement de troubles dabus/dpendance chez des personnes atteintes ou non de psychoses, la deuxime comparait lefficacit de la quetiapine et sa relation dose-rponse parmi diffrents dsordres psychiatriques. Mthodes Pour nos tudes cas-tmoins, lensemble des symptmes psychiatriques et neurologiques ont t valus via lchelle du syndrome positif et ngatif (PANSS), lchelle de dpression de Calgary, lchelle des symptmes extrapyramidaux (ESRS) ainsi quavec lchelle dakathisie de Barnes. Rsultats la suite du traitement de 12 semaines avec la quetiapine, les groupes SCZ et DD recevaient des doses de quetiapine significativement plus leves (moyenne = 554 et 478 mg par jour, respectivement) par rapport au groupe SUD (moyenne = 150 mg par jour). Aussi, nous avons observ chez ces mmes patients SUD une plus importante baisse du montant dargent dpens par semaine en alcool et autres drogues, ainsi quune nette amlioration de la svrit de la toxicomanie comparativement aux patients DD. Par consquent, la fin de lessai de 12 semaines, il ny avait pas de diffrence significative dans largent dpens en alcool et drogues entre les deux groupes de toxicomanes iv or, les patients DD prsentait, comme au point de dpart, un score de toxicomanie plus svre que les SUD. tonnamment, aux points initial et final de ltude, le groupe DD souffrait de plus de symptmes parkinsoniens et de dpression que le groupe SCZ. Par ailleurs, nous avons trouv quinitiallement, les patients SUD prsentaient significativement plus dakathisie, mais quen cours de traitement, cette akathisie relie labus/dpendance de cannabis sest nettement amliore en comparaison aux patients SCZ. Enfin, les patients SUD ont bnfici dune plus grande diminution de leurs symptmes positifs que les 2 groupes atteints de schizophrnie. Conclusions Bref, lensemble de nos rsultats fait montre dune vulnrabilit accentue par les effets ngatifs de lalcool et autres drogues dans une population de patients schizophrnes. galement, ces rsultats suggrent que labus de substance en combinaison avec les tats de manque miment certains symptmes retrouvs en schizophrnie. De futures tudes seront ncessaires afin de dterminer le rle spcifique qua jou la quetiapine dans ces amliorations.
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Mmoire numris par la Division de la gestion de documents et des archives de l'Universit de Montral
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La schizophrnie est une psychopathologie largement htrogne caractrise entre autres par dimportantes dfaillances dans le fonctionnement cognitif et motionnel. En effet, par rapport la population gnrale, forte proportion de ces individus prsentent une mmoire dficitaire pour les vnements motionnels. ce jour, le peu dtudes qui se sont penches sur la mmoire motionnelle pisodique dans la schizophrnie, ont uniquement mis lemphase sur l'effet de la valence des stimuli (cest--dire le caractre agrable ou dsagrable du stimulus). Toutefois, aucune na investigu spcifiquement lintensit de la raction aux stimuli (cest--dire une faible par rapport une forte raction) malgr quantit de preuves faisant montre, dans la population gnrale, de diffrents processus de mmoire motionnelle pour des stimuli suscitant une forte raction par rapport ceux voquant une faible rponse. Ce manque est dautant plus flagrant tant donn le nombre dtudes ayant rapport un traitement et un encodage atypiques des motions spcifiquement au niveau de lintensit de la rponse subjective chez des patients atteints de schizophrnie. Autre fait important, il est tonnant de constater labsence de recherches sur les diffrences de sexe dans la mmoire motionnelle tant donn lensemble des divergences entre hommes et femmes atteints de schizophrnie au niveau de la prvalence, de lge de diagnostic, de la manifestation clinique, de lvolution de la maladie, de la rponse au traitement et des structures crbrales. Pour pallier ces lacunes, ce mmoire a valu : (1) leffet de la valence des stimuli et de l'intensit de la raction motionnelle au niveau des fonctions crbrales correspondant la mmoire motionnelle chez des patients atteints de schizophrnie comparativement des participants sains; et (2) les possibles diffrences de sexe dans les processus crbraux impliqus dans la mmoire motionnelle chez des patients atteints de schizophrnie par rapport des volontaires sains. Ainsi, la premire tude a compar les activations crbrales de patients atteints de schizophrnie par rapport des participants sains au cours dune tche de mmoire motionnelle dont les stimuli variaient la fois au niveau de la valence et de l'intensit de la raction subjective. 37 patients atteints de schizophrnie ainsi que 37 participants en bonne sant ont effectu cette tche de mmoire motionnelle lors dune session dimagerie par rsonance magntique fonctionnelle (IRMf). Pour toutes les conditions tudies (images ngatives, positives, de faible et de forte intensit), le groupe atteint de schizophrnie a perform significativement moins bien que les volontaires sains. Comparativement aux sujets sains, ils ont montr moins dactivations crbrales dans les rgions limbiques et prfrontales lors de la reconnaissance des images ngatives, mais ont prsent un patron d'activations similaire celui des participants sains lors de la reconnaissance des images charges positivement (activations observes dans le cervelet, le cortex temporal et prfrontal). Enfin, indpendamment de la valence des stimuli, les deux groupes ont dmontr une augmentation des activations crbrales pour les images de forte intensit par rapport celles de plus faible intensit. La seconde tude a quant elle explor les diffrences de sexe potentielles au niveau des activations crbrales associes la mmoire motionnelle dans la schizophrnie et dans la population en gnral. Nous avons compar 41 patients atteints de schizophrnie (20 femmes) 41 participants en bonne sant (19 femmes) alors quils effectuaient la mme tche de mmoire motionnelle mentionne plus haut. Or, pour cette tude, nous nous sommes concentrs sur les conditions suivantes : la reconnaissance dimages positives, ngatives et neutres. Nous n'avons pas observ de diffrences entre les hommes et les femmes au niveau des performances la tche de mmoire pour aucune des conditions. En ce qui a trait aux donnes de neuroimagerie, comparativement aux femmes en bonne sant, celles atteintes de schizophrnie ont montr une diminution des activations crbrales dans les rgions corticales du systme limbique (p. ex. cortex cingulaire moyen) et dans les rgions sous-corticales (p. ex. amygdale) lors de la reconnaissance d'images ngatives. Pour ce qui est de la condition positive, elles ont prsent, comparativement au groupe de femmes saines, des diminutions dactivations spcifiquement dans le cervelet ainsi que dans le gyrus frontal infrieur et moyen. Les hommes atteints de schizophrnie, eux, ont montr une augmentation dactivations par rapport aux hommes sains dans le gyrus prfrontal mdian lors de la reconnaissance des stimuli ngatifs ; ainsi que dans les rgions paritales, temporales et limbiques lors de la reconnaissance des stimuli positifs. Dans un autre ordre dides, notre analyse corrlationnelle a mis en vidence, chez les femmes, un lien significatif entre lactivit crbrale et les symptmes au cours de la mmoire des stimuli positifs, alors que chez les hommes atteints schizophrnie, ce lien a t observ au cours de la mmoire des stimuli ngatifs. Bref, lensemble de nos rsultats suggre, chez les patients atteints de schizophrnie, un fonctionnement crbral atypique spcifiquement lors de la reconnaissance dimages ngatives, mais un fonctionnement intact lors de la reconnaissance de stimuli positifs. De plus, nous avons mis en vidence la prsence de diffrences de sexe dans les activations crbrales associes la mmoire pisodique motionnelle soulignant ainsi l'importance dtudier sparment les hommes et les femmes atteints de schizophrnie dans le cadre de recherches sur les plans cognitif et motionnel.
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Les antipsychotiques de deuxime gnration (ADG) sont de plus en plus employs dans le traitement de troubles psychiatriques. Selon de nombreuses observations cliniques, les effets secondaires relis la prise dADG diffrent chez les patients atteints de schizophrnie (SCZ) et de maladies affectives (MA) prouvent divers. Ainsi, il savre ncessaire dtudier la frquence et l'intensit des effets secondaires induits par les ADG qui pourraient diffrer selon le diagnostic. Pour ce faire, nous avons effectu une revue systmatique de la littrature afin didentifier lensemble des tudes rapportant les effets secondaires de cinq ADG (aripiprazole, olanzapine, qutiapine, rispridone et ziprasidone) dans le traitement de la schizophrnie ou des maladies affectives. Les effets secondaires mtaboliques et extrapyramidaux ont t recueillis sparment pour les deux groupes de patients, puis ont t combins dans une mta-analyse. Des mta-rgressions ainsi que des sous-analyses ont galement t effectues dans le but de regarder leffet de diffrents modrateurs (i.e. ge, genre, et dose). Dans la prsente mta-analyse, 107 tudes ont t inclues. Les rsultats montrent que le traitement avec lolanzapine a occasionn une plus importante prise de poids chez les patients SCZ comparativement aux patients MA. De plus, le traitement la qutiapine a amen une hausse significative du taux de LDL et de cholestrol total dans le groupe SCZ par rapport au groupe MA. Selon nos rsultats, les symptmes extrapyramidaux taient plus frquents dans le groupe MA, except pour le traitement l'olanzapine qui a induit davantage de ces symptmes chez les patients SCZ. galement, nos rsultats suggrent que les patients SCZ seraient plus vulnrables certains effets mtaboliques induits par les ADG d une possible susceptibilit gntique ou la prsence de facteurs de risque associs au style de vie. D'autre part, les patients MA en comparaison aux SCZ taient plus enclins souffrir de troubles du mouvement induits par les ADG. Bref, les ADG semblent exacerber certains types deffets secondaires tout dpendant de la maladie dans laquelle on les utilise.
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Resumen tomado de la publicaci??n
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Interactive guided learning material for clinical year students; core concepts on schizophrenia
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Introduction: Schizophrenia is a serious and chronic mental illness that has effect on cognitive and social functioning of a person who suffers it. Recent research points out that social cognition subprocesses, such as Theory of Mind, social perception or emotional processing, have to do with some problems that patients show in their social adjustment. Aim: Assessing ability of recognizing mental states from facial expressions in schizophrenia patients compared to a control group. Subjects and methods: 17 stable schizophrenia patients who are aware of the illness and 17 healthy people, with the same age and sociocultural level, took the Reading the Mind in the Eyes Test Revised Version of Baron- Cohen. Results: Compared with the control group, subjects with schizophrenia showed much lower scores. Conclusions: It is confirmed that schizophrenia patients have impairments to understand facial expressions, especially from the eyes. That is typical of this illness, so it is necessary to do interventions at that point. Furthermore, inability to recognize emotions, as a domain of social cognition, contributes to deficit in functional outcome in schizophrenia. Finally, some treatment programs are put forward.
