RESUMO
OBJECTIVE: Although schizophrenia patients are at a heightened risk of exhibiting violent behaviours compared to the general population, few functional neuroimaging studies have explored the aberrant neurocircuitry underpinning such behaviours. This study aimed to identify disrupted resting-state activity and functional connectivity in schizophrenia patients with a history of violence. METHODS: Resting state functional magnetic resonance imaging data was collected from 62 schizophrenia patients and 25 healthy controls. Voxel-wise analyses of fractional amplitude of low frequency fluctuations (fALFF) were implemented to investigate disrupted regional patterns of spontaneous brain activity. Brain regions which yielded significant differences between groups were subsequently used as data-driven seeds for functional connectivity analyses. Finally, significant alterations (activity and connectivity) were correlated with lifetime violent behaviours. RESULTS: When compared to healthy controls, schizophrenia patients exhibited reduced fALFF in multiple brain regions including the (subgenual) anterior cingulate cortex (ACC), posterior cingulate cortex, precuneus cortex and left lateral orbitofrontal cortex (OFC). Seed-to-voxel analyses yielded significantly enhanced connectivity between the ACC and left OFC. The heightened functional connectivity between the latter two regions predicted the number of violent behaviours reported by schizophrenia patients. CONCLUSION: The current study demonstrated that the functional connectivity of brain regions associated with emotion regulation is impaired in schizophrenia and associated with violent antecedents among patients. This result is consistent with predominant theoretical models proposing that the OFC plays a critical role in the neurobiology of violence.
Assuntos
Esquizofrenia , Encéfalo , Mapeamento Encefálico/métodos , Giro do Cíngulo , Humanos , Imageamento por Ressonância Magnética/métodosRESUMO
BACKGROUND: The high rate of suicidal behaviours (SBs) in psychiatric populations remain an important preoccupation to address. The literature reveals emotional instability as an important risk factor for SBs. However, the neural mechanisms underpinning this risk factor have never been investigated in schizophrenia patients with SBs. The following study implemented a task-based emotional processing functional magnetic resonance imaging (fMRI) paradigm to evaluate the activation and connectivity differences exhibited by schizophrenia patients with a history of suicide attempt (SA). METHOD: A sample of 62 schizophrenia patients with and without SA and 22 controls completed an fMRI emotional processing task, which included the visualization of dynamic angry facial expressions. Task-based connectivity was assessed using generalized psychophysical interaction analyses. RESULTS: During the processing of angry faces, suicidal schizophrenia patients displayed increased activation of the left median cingulate gyrus, left middle frontal gyrus, and left precuneus when compared to nonsuicidal schizophrenia patients and healthy controls. Whole-brain connectivity analyses yielded an increased coupling of the right amygdala and right superior frontal gyrus, as well as between the left precuneus and median cingulate gyrus, in suicidal schizophrenia patients. Schizophrenia patients' hostility scores on the Positive and Negative Symptom Scale (PANSS) were significantly and positively correlated with the activity of the left median cingulate gyrus. CONCLUSION: When exposed to angry faces, suicidal schizophrenia patients demonstrate elevated activation of brain regions associated to executive functioning and self-processing, as well as aberrant fronto-limbic connectivity involved in emotion regulation. Our results highlight the neglected role of anger when investigating the neural alterations underpinning SBs in schizophrenia.
Assuntos
Ira/fisiologia , Encéfalo/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Psicologia do Esquizofrênico , Tentativa de Suicídio/psicologia , Estudos de Coortes , Expressão Facial , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa/métodos , Esquizofrenia/fisiopatologia , Tentativa de Suicídio/tendências , Adulto JovemRESUMO
Eis um questionamento inabitual que deixa um pouco perplexo em razão mesmode sua formulação. Aqui, não se trata mais diretamente do debate, doravante clássico, apropósito da dignidade do morrer, mas da aproximação de duas palavras maciças eaparentemente contraditórias: morrer e curar. Dessa inusitada união resulta um choque,um estouro do bom senso, sobretudo se nos colocamos na perspectiva da doença terminal.Como se pode morrer de uma doença incurável embora estando curado? Existe aí algumacoisa emaranhada, absurda, que não deixa de evocar a complexidade daquilo que se vivesem dúvida à aproximação da morte, mas também mais banalmente, todos os dias, tantoa incoerência e a contradição constituem uma parte de nossa existência(AU)
It is an unusual question which leaves us somewhat perplexed even in itsformulation. Here, it is no longer a matter of directly debating, henceforth classic, aboutthe dignity of dying, but the approach of two massive and apparently contradictory words:dying and healing. A shock will result from this uncommon union, a burst of commonsense, especially if we put ourselves from the perspective of the terminal illness. Howcan we die from an incurable disease despite being healed? There is somethingintertwined, absurd, that doesnt prevent us from evoking the complexity of whatundoubtedly lives close to death, but also more casually, every day, both the incoherenceand contradiction constitute a part of our existence(AU)