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Accumulating evidence implicates oxidative stress as a potential pathophysiological mechanism of schizophrenia. Accordingly, we synthesized new chemicals using apocynin and tandospirone as lead compounds (A-2, A-3 and A-4). These novel compounds decreased reactive oxygen species (ROS) concentrations in vitro and reversed decreases in glutathione levels in the medial prefrontal cortex of rats transiently exposed to MK-801, an N-methyl-d-aspartate receptor antagonist, in the neonatal period. To determine whether A-2, A-3 and A-4 show behavioral effects associated with antipsychotic properties, the effects of these compounds on methamphetamine (MAP)-induced locomotor and vertical activity were examined in the model rats. A-2 and A-3, administered for 14 days around the puberty period, ameliorated MAP-induced hyperlocomotion in MK-801-treated rats in the post-puberty period, while A-4 suppressed MAP-induced vertical activity. These findings indicate that apocynin-tandospirone derivatives present anti-dopaminergic effects and may alleviate psychotic symptoms of schizophrenia.
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BACKGROUND: The onset of schizophrenia is often preceded by a prodromal phase. However, it is difficult to predict the future transition to schizophrenia from the prodromal symptoms. Based on the diagnostic significance of Schneider's first rank symptoms (FRS), especially those representing "ego disorders (Ichstörungen)", we developed a scale of self-alienation-related attributes (Self-A) to assess the psychological characteristics associated with ego disorders for the early diagnosis of schizophrenia. METHODS: In total, 153 schizophrenia (Sz) patients, 83 at-risk mental state (ARMS) subjects, and 154 healthy control (HC) subjects participated in this study. The Self-A scale was constructed by items from the Minnesota Multiphasic Personality Inventory (MMPI) based on the differences between schizophrenia patients with and without FRS representing ego-disorders designated as "self-alienation symptoms". The Self-A scale was tested for its reliability and validity in a different sample of schizophrenia patients, and was then applied to different cohorts including first-episode schizophrenia (FES) patients, ARMS individuals, and HC subjects. RESULTS: The Self-A consisting of 27 items exhibited good internal consistency reliability. The validity was well demonstrated by the high correlation of the Self-A scores with the self-alienation symptom scores. The ARMS and FES groups had higher Self-A scores than the HC group. The Self-A score in the ARMS individuals who later developed schizophrenia was higher than that in the ARMS subjects who did not, and was comparable with that in the FES group. CONCLUSIONS: This study suggests that the newly developed Self-A scale assessing the self-alienation-related attributes can improve the early diagnosis of schizophrenia.
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Esquizofrenia , Diagnóstico Precoce , Emoções , Humanos , Sintomas Prodrômicos , Reprodutibilidade dos Testes , Esquizofrenia/diagnósticoRESUMO
BACKGROUND: Impaired self-awareness has often been described in schizophrenia. Recent neuroimaging studies examining the self-reflection processes in schizophrenia have produced inconsistent results. METHOD: We examined the self-reflective neural network using self- and other-evaluation tasks in schizophrenia. Fifteen schizophrenia patients and fifteen age- and sex-matched healthy subjects underwent functional magnetic resonance imaging. Subjects were required to decide whether the sentence described their own personal trait (self-evaluation) and that of their close friends (other-evaluation). RESULTS: Unlike normal control subjects, the schizophrenia patients did not have greater activation of the left posterior cingulate gyrus and hippocampus during self-evaluation than during other-evaluation. On the other hand, the schizophrenia patients had higher activation of the right superior frontal and right supramarginal gyri during self-evaluation than control subjects. Only the patient group exhibited hyperactivation in the left hippocampus and right external capsule associated with the other-evaluation task. CONCLUSIONS: These findings provide evidence for an altered neural basis of self-reflective processing, which may underlie the self-awareness deficits in schizophrenia.
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Esquizofrenia/diagnóstico por imagem , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Feminino , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Autoimagem , Autoavaliação (Psicologia)RESUMO
Antioxidant activity has been reported for some atypical antipsychotic drugs; however, the detailed mechanism is not well known. Here, we investigated the effects of atypical antipsychotic drugs on â¢OH radical formation, intracellular reactive oxygen species (ROS), and apoptosis induced by ionising radiation. The reaction rate constants with â¢OH radicals were determined for five antipsychotic drugs as follows, in descending order: olanzapine, aripiprazole, clozapine, haloperidol, and risperidone. Experiments with aminophenyl fluorescein, a fluorescent dye, showed that olanzapine and clozapine could scavenge intracellular ROS. However, experiments with hydroxyphenyl fluorescein showed that only olanzapine inhibited ROS generation. X-irradiation-induced apoptosis in human lymphoma U937 cells was inhibited by clozapine at relatively low concentrations and by olanzapine at higher concentrations. Clozapine inhibited caspase-8 and caspase-3 activation and prevented loss of mitochondrial membrane potential. In contrast, olanzapine inhibited X-irradiation-induced p-JNK activation. Although the atypical antipsychotic drugs used here have relatively high reaction rate constants with â¢OH radicals in aqueous solutions, inhibition of intracellular ROS was not due to â¢OH radical scavenging. In addition, suppression of X-irradiation-induced apoptosis was not directly linked with intracellular ROS scavenging. When apoptosis signalling pathways were studied, clozapine-mediated inhibition of apoptosis was dependent on caspase-3 and caspase-8. In contrast, olanzapine inhibited apoptosis via down regulation of X-irradiation-induced p-JNK. These results suggested that both olanzapine and clozapine have antioxidative and antiapoptotic activities via distinct pathways, and provide useful information for better understanding of drug characteristics.
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Antipsicóticos/uso terapêutico , Radical Hidroxila/metabolismo , Linfoma/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Antipsicóticos/farmacologia , Apoptose , Humanos , Linfoma/patologia , Células U937RESUMO
BACKGROUND: A recent review reported that the median proportion of patients recovering from schizophrenia was 13.5% and that this did not change over time. Various factors including the duration of untreated psychosis, cognitive impairment, negative symptoms, and morphological changes in the brain influence the functional outcome of schizophrenia. The authors herein reviewed morphological changes in the brain of schizophrenia patients, effects of early intervention, and a direction of developing novel therapeutics to achieve significant improvement of the functional outcome. METHODS: A selective review of the literature including studies from our department was performed. RESULTS: Longitudinal structural neuroimaging studies on schizophrenia revealed that volume reductions in the peri-Sylvian regions (e.g., superior temporal gyrus and insula), which are related to positive psychotic symptoms, progress around the onset (critical stage) of schizophrenia, but become stable in the chronic stage. On the other hand, morphological changes in the fronto-thalamic regions and lateral ventricle, which are related to negative symptoms, neurocognitive dysfunction, and the functional outcome, progress during both the critical and chronic stages. These changes in the peri-Sylvian and fronto-thalamic regions may provide a pathophysiological basis for Crow's two-syndrome classification. Accumulated evidence from early intervention trials suggests that the transition risk from an at-risk mental state (ARMS) to psychosis is approximately 30%. Differences in the cognitive performance, event-related potentials (e.g., mismatch negativity), and brain morphology have been reported between ARMS subjects who later developed psychosis and those who did not. Whether early intervention for ARMS significantly improves the long-term recovery rate of schizophrenia patients remains unknown. With respect to the development of novel therapeutics, animal models of schizophrenia based on the N-methyl-d-aspartate receptor hypofunction hypothesis successfully mimicked behavioral changes associated with cognitive impairments characteristic of the disease. Furthermore, these animal models elicited histological changes in the brain similar to those observed in schizophrenia patients, i.e., decreased numbers of parvalbumin-positive interneurons and dendritic spines of pyramidal neurons in the frontal cortex. Some antioxidant compounds were found to ameliorate these behavioral and histological abnormalities. CONCLUSION: Early intervention coupled with novel therapeutics may offer a promising approach for substantial improvement of the functional outcome of schizophrenia patients.
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The role of mental symptomatology is to describe various clinical symptoms without refer- ring to their pathogenesis. This may be because of the influence of K. Jasper's General Psycho- pathology. However, from the mid-19th to early 20th century, when modern psychiatry was estab- lished, some excellent hypotheses concerning the pathogenesis of mental symptoms were pro- posed, although it was difficult to verify these hypotheses because of technical limitations. The purpose of this article was to review the historical development of symptomatology in psycho- sis with reference to the pathogenesis. W. Griesinger (1845, 1861) distinguished between the etiology and pathogenesis of a disease, and stated that every mental disease is a manifestation of brain disease. Subsequent investigators elaborated on this view : C. Wernicke (1894, 1906) proposed the disconnection of the association tracts, and P. Flechsig (1894, 1920) regarded the late myelinating "association areas"' (this term was from Flechsig) as the field of the mind. J. H. Jackson (1895) proposed the evolutionary and hierarchical organization of the nervous system. E. Kraepelin (1913) speculated on the hypoactivity of the frontal cortex-the highest cerebral centers according to Jackson's terminology-and hyperactivity of the temporal speech cortex as the pathogenesis of psychotic symptoms in dementia praecox, which were found to be the case based on neuroimaging methods over sixty years later. Currently, the pathogenesis of mental symptoms is being investigated from the viewpoint of the dysfunctions of neural cir- cuits, such as cortico-limbic, cortico-thalamic, or cortico-striatal circuitry.
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Transtornos Psicóticos , Encéfalo , Humanos , Psiquiatria/classificação , Transtornos Psicóticos/classificaçãoRESUMO
Schizophrenia is considered a neurodevelopmental and neurodegenerative disorder. Cognitive impairment is a core symptom in patients with the illness, and has been suggested a major predictor of functional outcomes. Reduction of parvalbumin (PV)-positive γ-aminobutyric acid (GABA) interneurons has been associated with the pathophysiology of schizophrenia, in view of the link between the abnormality of GABA neurons and cognitive impairments of the disease. It is assumed that an imbalance of excitatory and inhibitory (E-I) activity induced by low activity of glutamatergic projections and PV-positive GABA interneurons in the prefrontal cortex resulted in sustained neural firing and gamma oscillation, leading to impaired cognitive function. Therefore, it is important to develop novel pharmacotherapy targeting GABA neurons and their activities. Clinical evidence suggests serotonin (5-HT) 1A receptor agonist improves cognitive disturbances of schizophrenia, consistent with results from preclinical studies, through mechanism that corrects E-I imbalance via the suppression of GABA neural function. On the other hand, T-817MA, a novel neurotrophic agent, ameliorated loss of PV-positive GABA neurons in the medial prefrontal cortex and reduction of gamma-band activity, as well as cognitive dysfunction in animal model of schizophrenia. In conclusion, a pharmacotherapy to alleviate abnormalities in GABA neurons through 5-HT1A agonists and T-817MA is expected to prevent the onset and/or progression of schizophrenia.
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Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/metabolismo , Psicotrópicos/uso terapêutico , Esquizofrenia/tratamento farmacológico , Esquizofrenia/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Transtornos Cognitivos/complicações , Humanos , Psicotrópicos/farmacologia , Receptor 5-HT1A de Serotonina/metabolismo , Esquizofrenia/complicações , Psicologia do EsquizofrênicoRESUMO
Sleep can integrate information into existing memory networks, look for common patterns and distil overarching rules, or simply stabilize and strengthen the memory exactly as it was learned. Recent research has shown that sleep facilitates abstraction of gist information as well as integration across multiple memories, insight into hidden solutions, and even the ability to make creative connections between distantly related ideas and concepts. To investigate the effect of sleep on memory organization, 35 normal volunteers were randomly assigned either to the sleep (n = 17) or wake group (n = 18). The sleep subjects performed the Japanese Verbal Learning Test (JVLT), a measure of learning and memory, three times in the evening, and slept. On the following morning (9 h later), they were asked to recall the words on the list. The wake subjects took the same test in the morning, and were asked to recall the words in the same time interval as in the sleep group. The semantic clustering ratio (SCR), divided by the total number of words recalled, was used as an index of memory organization. Our main interest was whether the sleep subjects elicit a greater increase in this measure from the third to the fourth assessments. Time × Group interaction effect on SCR was not significant between the sleep group and wake group as a whole. Meanwhile, the change in the SCR between the third and fourth trials was negatively correlated with duration of nocturnal waking in the sleep group, but not other sleep indices. Based on this observation, further analysis was conducted for subjects in the sleep group who awoke nocturnally for <60 min for comparison with the wake group. A significant Time × Group interaction was noted; these "good-sleepers" showed a significantly greater improvement in the memory index compared with the wake subjects. These results provide the first suggestion that sleep may enhance memory organization, which requires further study.
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Schizophrenia is considered as a "neurodegenerative" and "neurodevelopmental" disorder, the pathophysiology of which may include hypofunction of the N-methyl-D-aspartate receptor (NMDA-R) or subsequent pathways. Accordingly, administration of NMDA-R antagonists to rodents during the perinatal period may emulate some core pathophysiological aspects of schizophrenia. The effect of 4-day (postnatal day; PD 7-10) administration of MK-801, a selective NMDA-R antagonist, on gene expression in the medial prefrontal cortex (mPFC), hippocampus, and amygdala was evaluated using quantitative polymerase chain reaction methods. Specifically, we sought to determine whether genes related to Glu transmissions, for example those encoding for NMDA-Rs, metabotropic Glu receptors (mGluRs), or Glu transporters, were altered by neonatal treatment with MK-801. Model rats showed downregulation of the mGluR3 subtype in the mPFC around puberty, especially at PD 35 in response to MK-801 or during ontogenesis without pharmacological manipulations. Genes encoding for other mGluRs subtypes, that is NMDA-Rs and Glu transporters, were not affected by the neonatal insult. These results suggest that NMDA-R antagonism in the early course of development modulates the expression of mGluR3 in mPFC around puberty. Thus, mGluR3 may serve as a potential target to prevent the onset and progression of schizophrenia.
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Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Córtex Pré-Frontal/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Animais , Regulação para Baixo , Feminino , Córtex Pré-Frontal/crescimento & desenvolvimento , Córtex Pré-Frontal/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/genética , Fatores de TempoAssuntos
Comportamento Exploratório , Movimentos Oculares , Esquizofrenia/fisiopatologia , Adulto , Feminino , Humanos , MasculinoRESUMO
Consumption of methamphetamine disturbs dopaminergic transmission and sometimes provokes schizophrenia-like-psychosis, named methamphetamine-associated psychosis (MAP). While previous studies have repeatedly reported regional volume reductions in the frontal and temporal areas as neuroanatomical substrates for psychotic symptoms, no study has examined whether such neuroanatomical substrates exist or not in patients with MAP. Magnetic resonance images obtained from twenty patients with MAP and 20 demographically-matched healthy controls (HC) were processed for voxel-based morphometry (VBM) using Diffeomorphic Anatomical Registration using Exponentiated Lie Algebra. An analysis of covariance model was adopted to identify volume differences between subjects with MAP and HC, treating intracranial volume as a confounding covariate. The VBM analyses showed significant gray matter volume reductions in the left perisylvian structures, such as the posterior inferior frontal gyrus and the anterior superior temporal gyrus, and the frontopolar cortices, including its dorsomedial, ventromedial, dorsolateral, and ventrolateral portions, and white matter volume reduction in the orbitofrontal area in the patients with MAP compared with the HC subjects. The smaller regional gray matter volume in the medial portion of the frontopolar cortex was significantly correlated with the severe positive symptoms in the individuals with MAP. The volume reductions in the left perisylvian structure suggest that patients with MAP have a similar pathophysiology to schizophrenia, whereas those in the frontopolar cortices and orbitofrontal area suggest an association with antisocial traits or vulnerability to substance dependence.
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Lobo Frontal/patologia , Lateralidade Funcional , Transtornos Psicóticos/patologia , Lobo Temporal/patologia , Adulto , Estudos de Casos e Controles , Estimulantes do Sistema Nervoso Central/toxicidade , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Metanfetamina/toxicidade , Transtornos Psicóticos/etiologia , Adulto JovemRESUMO
We report our activity in the Consultation and Support Service in Toyama (CAST), a clinical service provided by the collaboration of Toyama Prefectural Mental Health Center and University Hospital of Toyama(UHT). About 23% of users diagnosed with at-risk mental state (ARMS), during October 2006 until March 2012, transitioned to overt schizophrenia. More than half of the subjects who continued to visit the specialized clinic in UHT were treated with antipsychotic drugs. We encountered a case of schizophrenia in which early treatment with an atypical psychotic drug was effective in normalizing cognitive function and achieving a good social consequence. The ability of mismatch negativity, an event-related potential, to predict progression to psychosis in subjects with ARMS is discussed. Further efforts should be directed towards improving long-term outcomes, such as social function, for users of the CAST.
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Intervenção Educacional Precoce , Transtornos Psicóticos/terapia , Esquizofrenia/terapia , Diagnóstico Diferencial , Intervenção Educacional Precoce/métodos , Humanos , Japão , Transtornos Psicóticos/diagnóstico , Fatores de Risco , Esquizofrenia/diagnóstico , Resultado do TratamentoRESUMO
This longitudinal MRI study investigated the pituitary volume in 17 patients with chronic schizophrenia and 17 matched controls. In contrast to previous findings of pituitary expansion during the first episode of schizophrenia, the chronic patients showed non-significant mild pituitary atrophy, suggesting that the pituitary volume changes differently at different illness stages.
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Hipófise/patologia , Esquizofrenia/patologia , Adulto , Atrofia/patologia , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do ÓrgãoRESUMO
AIM: Many psychophysiological tests have been widely researched in the search for a biological marker of schizophrenia. The exploratory eye movement (EEM) test involves the monitoring of eye movements while subjects freely view geometric figures. Suzuki et al. (2009) performed discriminant analysis between schizophrenia and non-schizophrenia subjects using EEM test data; consequently, clinically diagnosed schizophrenia patients were identified as having schizophrenia with high probability (73.3%). The aim of the present study was to investigate the characteristics of schizophrenia patients who were identified as having schizophrenia on EEM discriminant analysis (SPDSE) or schizophrenia patients who were identified as not having schizophrenia on EEM discriminant analysis (SPDNSE). METHODS: The data for the 251 schizophrenia subjects used in the previous discriminant-analytic study were analyzed, and the demographic or symptomatic characteristics of SPDSE and SPDNSE were investigated. As for the symptomatic features, a factor analysis of the Brief Psychiatric Rating Scale (BPRS) rating from the schizophrenia subjects was carried out. RESULTS: Five factors were found for schizophrenia symptoms: excitement/hostility; negative symptoms; depression/anxiety; positive symptoms; and disorganization. SPDSE had significantly higher factor scores for excitement/hostility, negative symptoms and disorganization than SPDNSE. Furthermore, the BPRS total score for the SPDSE was significantly higher than that for the SPDNSE. CONCLUSION: SPDSE may be a disease subtype of schizophrenia with severe symptoms related to excitement/hostility, negative symptoms and disorganization, and EEM parameters may detect this subtype. Therefore, the EEM test may be one of the contributors to the simplification of the heterogeneity of schizophrenia.
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Comportamento Exploratório/fisiologia , Transtornos da Motilidade Ocular/psicologia , Psicologia do Esquizofrênico , Adulto , Antipsicóticos/uso terapêutico , Interpretação Estatística de Dados , Movimentos Oculares/fisiologia , Análise Fatorial , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Esquizofrenia/classificação , Esquizofrenia/complicaçõesRESUMO
T-817MA [1-{3-[2-(1-benzothiophen-5-yl)ethoxy]propyl}azetidin-3-ol maleate] is a newly synthesized neuroprotective agent for the treatment of psychiatric disorders characterized by cognitive disturbances, such as Alzheimer's disease. Cognitive impairment has also been suggested to be a cardinal feature of schizophrenia. We sought to determine whether T-817MA would ameliorate sensorimotor gating deficits and loss of parvalbumin (PV)-positive γ-aminobutyric acid (GABA) neurons in the brain of rats transiently exposed to MK-801, an N-methyl-d-aspartate receptor blocker, in the neonatal stage, as an animal model of schizophrenia. Prepulse inhibition (PPI) was examined in rats treated neonatally with MK-801 (postnatal day; PD 7-10, 0.2 mg/kg/day, s.c.) or vehicle at PD 35 and PD 63. The number of PV-positive GABAergic neurons in the medial prefrontal cortex (mPFC) and the hippocampus was measured after the behavioral assessments. T-817MA (10 or 20 mg/kg) or vehicle was administered for 14 days (on PD 49-62). Administration of T-817MA at 20 mg/kg, but not 10 mg/kg, ameliorated PPI deficits and completely reversed the decrease in the number of PV-positive GABAergic neurons in rats given MK-801. These results indicate that T-817MA may provide a novel therapeutic approach for the treatment of cognitive deficits of schizophrenia.
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Encéfalo/patologia , Neurônios GABAérgicos/metabolismo , Transtornos Neurológicos da Marcha/tratamento farmacológico , Maleatos/uso terapêutico , Fatores de Crescimento Neural/uso terapêutico , Parvalbuminas/metabolismo , Tiofenos/uso terapêutico , Estimulação Acústica , Fatores Etários , Análise de Variância , Animais , Animais Recém-Nascidos , Maleato de Dizocilpina/toxicidade , Antagonistas de Aminoácidos Excitatórios/toxicidade , Feminino , Neurônios GABAérgicos/efeitos dos fármacos , Transtornos Neurológicos da Marcha/induzido quimicamente , Transtornos Neurológicos da Marcha/patologia , Masculino , Inibição Neural/efeitos dos fármacos , Gravidez , Psicoacústica , Distribuição Aleatória , Ratos , Ratos Wistar , Reflexo de Sobressalto/efeitos dos fármacosRESUMO
The number of parvalbumin (PV)-positive γ -aminobutyric acid (GABA) neurons is decreased in the brain of rats transiently exposed to MK-801, an N-methyl-D-aspartate (NMDA) receptor blocker, in the neonatal stage (Uehara et al. (2012)). T-817MA [1-{3-[2-(1-benzothiophen-5-yl)ethoxy]propyl} azetidin-3-ol maleate] is a neuroprotective agent synthesized for the treatment of psychiatric disorders characterized by cognitive disturbances, such as dementia. We herein sought to determine whether T-817MA, haloperidol (HPD), or risperidone (RPD) would ameliorate the decrease in the number of PV-positive GABA neurons in the medial prefrontal cortex (mPFC) and hippocampus of the model animals. Rats were treated with MK-801 (0.2 mg/kg/day) or vehicle on postnatal days (PD) 7-10, and the number of PV-positive neurons in the mPFC and hippocampus were measured on PDs 63. T-817MA (20 mg/kg), HPD (1 mg/kg), or RPD (1 mg/kg) were administered during PDs 49-62. Fourteen-day administration of T-817MA reversed the decrease in the number of PV-positive neurons in the above brain regions of rats given MK-801, whereas HPD and RPD were ineffective. These results indicate that T-817MA provides a novel pharmacologic strategy to enhance cognitive function in patients with schizophrenia.
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While longitudinal magnetic resonance imaging (MRI) studies have demonstrated progressive gray matter reduction of the superior temporal gyrus (STG) during the early phases of schizophrenia, it remains largely unknown whether other temporal lobe structures also exhibit similar progressive changes and whether these changes, if present, are specific to schizophrenia among the spectrum disorders. In this longitudinal MRI study, the gray matter volumes of the fusiform, middle temporal, and inferior temporal gyri were measured at baseline and follow-up scans (mean inter-scan interval=2.7 years) in 18 patients with first-episode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. Both schizophrenia and schizotypal patients had a smaller fusiform gyrus than controls bilaterally at both time points, whereas no group difference was found in the middle and inferior temporal gyri. In the longitudinal comparison, the schizophrenia patients showed significant fusiform gyrus reduction (left, -2.6%/year; right, -2.3%/year) compared with schizotypal patients (left: -0.4%/year; right: -0.2%/year) and controls (left: 0.1%/year; right: 0.0%/year). However, the middle and inferior temporal gyri did not exhibit significant progressive gray matter change in all diagnostic groups. In the schizophrenia patients, a higher cumulative dose of antipsychotics during follow-up was significantly correlated with less severe gray matter reduction in the left fusiform gyrus. The annual gray matter loss of the fusiform gyrus did not correlate with that of the STG previously reported in the same subjects. Our findings suggest regional specificity of the progressive gray matter reduction in the temporal lobe structures, which might be specific to overt schizophrenia within the schizophrenia spectrum.
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Esquizofrenia/patologia , Lobo Temporal/patologia , Adolescente , Adulto , Atrofia/patologia , Feminino , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Tamanho do ÓrgãoRESUMO
The similarity between psychotic symptoms in patients with schizophrenia such as hallucinations and delusions and those caused by administration of methamphetamine has been accepted. While the etiology of schizophrenia remains unclear, methamphetamine induced psychosis, which is obviously occurred by methamphetamine administration, had been widely considered as a human pharmaceutical model of exogenous psychosis. Although volume reductions in medial temporal lobe structure in patients with schizophrenia have repeatedly been reported, those in patients with methamphetamine psychosis have not yet been clarified. Magnetic resonance images (MRI) were obtained from 20 patients with methamphetamine psychosis and 20 age, sex, parental socio-economic background, and IQ matched healthy controls. A reliable manual tracing methodology was employed to measure the gray matter volume of the amygdala and the hippocampus from MRIs. Significant gray matter volume reductions of both the amygdala and hippocampus were found bilaterally in the subjects with methamphetamine psychosis compared with the controls. The degree of volume reduction was significantly greater in the amygdala than in hippocampus. While the total gray, white matter and intracranial volumes were also significantly smaller-than-normal in the patients; the regional gray matter volume reductions in these medial temporal structures remained statistically significant even after these global brain volumes being controlled. The prominent volume reduction in amygdala rather than that in hippocampus could be relatively specific characteristics of methamphetamine psychosis, since previous studies have shown significant volume reductions less frequently in amygdala than in hippocampus of the other psychosis such as schizophrenia.
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Tonsila do Cerebelo/patologia , Estimulantes do Sistema Nervoso Central/efeitos adversos , Hipocampo/patologia , Metanfetamina/efeitos adversos , Transtornos Psicóticos/etiologia , Transtornos Psicóticos/patologia , Adulto , Análise de Variância , Mapeamento Encefálico , Estudos de Casos e Controles , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
This study examined the size of the useful visual field in patients (9 men, 6 women) with schizophrenia. A choice reaction task was conducted, and performances at 2.5, 5, 7, 10, and 25 degrees in both visual fields were measured. Three key findings were shown. First, patients had slower choice reaction times (choice RTs) than normal controls. Second, patients had slower choice RTs in the right visual field than in the left visual field. Third, patients and normal controls showed the same U-shaped choice RT pattern. The first and second findings were consistent with those of other studies. The third finding was a clear indication of the patients' performance in peripheral vision, and a comparison with normal controls suggested that there was no difference in the size of the useful visual field, at least within
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Comportamento de Escolha , Tempo de Reação , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Campos Visuais , Adolescente , Adulto , Atenção , Movimentos Oculares , Feminino , Humanos , Masculino , Orientação , Valores de Referência , Adulto JovemRESUMO
BACKGROUND: Although structural magnetic resonance imaging (MRI) studies have repeatedly demonstrated regional brain structural abnormalities in patients with schizophrenia, relatively few MRI-based studies have attempted to distinguish between patients with first-episode schizophrenia and healthy controls. METHOD: Three-dimensional MR images were acquired from 52 (29 males, 23 females) first-episode schizophrenia patients and 40 (22 males, 18 females) healthy subjects. Multiple brain measures (regional brain volume and cortical thickness) were calculated by a fully automated procedure and were used for group comparison and classification by linear discriminant function analysis. RESULTS: Schizophrenia patients showed gray matter volume reductions and cortical thinning in various brain regions predominantly in prefrontal and temporal cortices compared with controls. The classifiers obtained from 66 subjects of the first group successfully assigned 26 subjects of the second group with accuracy above 80%. CONCLUSION: Our results showed that combinations of automated brain measures successfully differentiated first-episode schizophrenia patients from healthy controls. Such neuroimaging approaches may provide objective biological information adjunct to clinical diagnosis of early schizophrenia.