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1.
Mol Psychiatry ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38693319

RESUMO

Reduced processing speed is a core deficit in major depressive disorder (MDD) and has been linked to altered structural brain network connectivity. Ample evidence highlights the involvement of genetic-immunological processes in MDD and specific depressive symptoms. Here, we extended these findings by examining associations between polygenic scores for tumor necrosis factor-α blood levels (TNF-α PGS), structural brain connectivity, and processing speed in a large sample of MDD patients. Processing speed performance of n = 284 acutely depressed, n = 177 partially and n = 198 fully remitted patients, and n = 743 healthy controls (HC) was estimated based on five neuropsychological tests. Network-based statistic was used to identify a brain network associated with processing speed. We employed general linear models to examine the association between TNF-α PGS and processing speed. We investigated whether network connectivity mediates the association between TNF-α PGS and processing speed. We identified a structural network positively associated with processing speed in the whole sample. We observed a significant negative association between TNF-α PGS and processing speed in acutely depressed patients, whereas no association was found in remitted patients and HC. The mediation analysis revealed that brain connectivity partially mediated the association between TNF-α PGS and processing speed in acute MDD. The present study provides evidence that TNF-α PGS is associated with decreased processing speed exclusively in patients with acute depression. This association was partially mediated by structural brain connectivity. Using multimodal data, the current findings advance our understanding of cognitive dysfunction in MDD and highlight the involvement of genetic-immunological processes in its pathomechanisms.

2.
Schizophr Res ; 266: 237-248, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38431986

RESUMO

BACKGROUND: We examined the course of illness over a 12-month period in a large, international multi-center cohort of people with a first-episode schizophrenia spectrum disorder (FES) in a naturalistic, prospective study (PSYSCAN). METHOD: Patients with a first episode of schizophrenia, schizoaffective disorder (depressive type) or schizophreniform disorder were recruited at 16 institutions in Europe, Israel and Australia. Participants (N = 304) received clinical treatment as usual throughout the study. RESULTS: The mean age of the cohort was 24.3 years (SD = 5.6), and 67 % were male. At baseline, participants presented with a range of intensities of psychotic symptoms, 80 % were taking antipsychotic medication, 68 % were receiving psychological treatment, with 46.5 % in symptomatic remission. The mean duration of untreated psychosis was 6.2 months (SD = 17.0). After one year, 67 % were in symptomatic remission and 61 % were in functional remission, but 31 % had been readmitted to hospital at some time after baseline. In the cohort as a whole, depressive symptoms remained stable over the follow-up period. In patients with a current depressive episode at baseline, depressive symptoms slightly improved. Alcohol, tobacco and cannabis were the most commonly used substances, with daily users of cannabis ranging between 9 and 11 % throughout the follow-up period. CONCLUSIONS: This study provides valuable insight into the early course of a broad range of clinical and functional aspects of illness in FES patients in routine clinical practice.


Assuntos
Antipsicóticos , Transtornos Psicóticos , Esquizofrenia , Humanos , Masculino , Adulto Jovem , Adulto , Feminino , Esquizofrenia/epidemiologia , Esquizofrenia/terapia , Esquizofrenia/diagnóstico , Estudos de Coortes , Estudos Prospectivos , Resultado do Tratamento , Transtornos Psicóticos/epidemiologia , Transtornos Psicóticos/terapia , Transtornos Psicóticos/diagnóstico , Antipsicóticos/uso terapêutico , Seguimentos
3.
BMC Med ; 21(1): 93, 2023 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-36907864

RESUMO

BACKGROUND: Childhood maltreatment is associated with depression and cardiometabolic disease in adulthood. However, the relationships with these two diseases have so far only been evaluated in different samples and with different methodology. Thus, it remains unknown how the effect sizes magnitudes for depression and cardiometabolic disease compare with each other and whether childhood maltreatment is especially associated with the co-occurrence ("comorbidity") of depression and cardiometabolic disease. This pooled analysis examined the association of childhood maltreatment with depression, cardiometabolic disease, and their comorbidity in adulthood. METHODS: We carried out an individual participant data meta-analysis on 13 international observational studies (N = 217,929). Childhood maltreatment comprised self-reports of physical, emotional, and/or sexual abuse before 18 years. Presence of depression was established with clinical interviews or validated symptom scales and presence of cardiometabolic disease with self-reported diagnoses. In included studies, binomial and multinomial logistic regressions estimated sociodemographic-adjusted associations of childhood maltreatment with depression, cardiometabolic disease, and their comorbidity. We then additionally adjusted these associations for lifestyle factors (smoking status, alcohol consumption, and physical activity). Finally, random-effects models were used to pool these estimates across studies and examined differences in associations across sex and maltreatment types. RESULTS: Childhood maltreatment was associated with progressively higher odds of cardiometabolic disease without depression (OR [95% CI] = 1.27 [1.18; 1.37]), depression without cardiometabolic disease (OR [95% CI] = 2.68 [2.39; 3.00]), and comorbidity between both conditions (OR [95% CI] = 3.04 [2.51; 3.68]) in adulthood. Post hoc analyses showed that the association with comorbidity was stronger than with either disease alone, and the association with depression was stronger than with cardiometabolic disease. Associations remained significant after additionally adjusting for lifestyle factors, and were present in both males and females, and for all maltreatment types. CONCLUSIONS: This meta-analysis revealed that adults with a history of childhood maltreatment suffer more often from depression and cardiometabolic disease than their non-exposed peers. These adults are also three times more likely to have comorbid depression and cardiometabolic disease. Childhood maltreatment may therefore be a clinically relevant indicator connecting poor mental and somatic health. Future research should investigate the potential benefits of early intervention in individuals with a history of maltreatment on their distal mental and somatic health (PROSPERO CRD42021239288).


Assuntos
Doenças Cardiovasculares , Maus-Tratos Infantis , Masculino , Adulto , Feminino , Criança , Humanos , Depressão , Maus-Tratos Infantis/psicologia , Comorbidade , Autorrelato , Doenças Cardiovasculares/epidemiologia
4.
Hum Brain Mapp ; 43(11): 3577-3584, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35411559

RESUMO

Stressful life events (SLEs) in adulthood are a risk factor for various disorders such as depression, cancer or infections. Part of this risk is mediated through pathways altering brain physiology and structure. There is a lack of longitudinal studies examining associations between SLEs and brain structural changes. High-resolution structural magnetic resonance imaging data of 212 healthy subjects were acquired at baseline and after 2 years. Voxel-based morphometry was used to identify associations between SLEs using the Life Events Questionnaire and grey matter volume (GMV) changes during the 2-year period in an ROI approach. Furthermore, we assessed adverse childhood experiences as a possible moderator of SLEs-GMV change associations. SLEs were negatively associated with GMV changes in the left medial prefrontal cortex. This association was stronger when subjects had experienced adverse childhood experiences. The medial prefrontal cortex has previously been associated with stress-related disorders. The present findings represent a potential neural basis of the diathesis-stress model of various disorders.


Assuntos
Encéfalo , Substância Cinzenta , Adulto , Encéfalo/patologia , Córtex Cerebral , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética/métodos , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/patologia
5.
Mol Psychiatry ; 27(2): 1111-1119, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34782712

RESUMO

Major Depressive Disorder (MDD) often is associated with significant cognitive dysfunction. We conducted a meta-analysis of genome-wide interaction of MDD and cognitive function using data from four large European cohorts in a total of 3510 MDD cases and 6057 controls. In addition, we conducted analyses using polygenic risk scores (PRS) based on data from the Psychiatric Genomics Consortium (PGC) on the traits of MDD, Bipolar disorder (BD), Schizophrenia (SCZ), and mood instability (MIN). Functional exploration contained gene expression analyses and Ingenuity Pathway Analysis (IPA®). We identified a set of significantly interacting single nucleotide polymorphisms (SNPs) between MDD and the genome-wide association study (GWAS) of cognitive domains of executive function, processing speed, and global cognition. Several of these SNPs are located in genes expressed in brain, with important roles such as neuronal development (REST), oligodendrocyte maturation (TNFRSF21), and myelination (ARFGEF1). IPA® identified a set of core genes from our dataset that mapped to a wide range of canonical pathways and biological functions (MPO, FOXO1, PDE3A, TSLP, NLRP9, ADAMTS5, ROBO1, REST). Furthermore, IPA® identified upstream regulator molecules and causal networks impacting on the expression of dataset genes, providing a genetic basis for further clinical exploration (vitamin D receptor, beta-estradiol, tadalafil). PRS of MIN and meta-PRS of MDD, MIN and SCZ were significantly associated with all cognitive domains. Our results suggest several genes involved in physiological processes for the development and maintenance of cognition in MDD, as well as potential novel therapeutic agents that could be explored in patients with MDD associated cognitive dysfunction.


Assuntos
Transtorno Depressivo Maior , Cognição , Depressão , Transtorno Depressivo Maior/genética , Transtorno Depressivo Maior/psicologia , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Herança Multifatorial/genética , Proteínas do Tecido Nervoso/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores Imunológicos
6.
Soc Cogn Affect Neurosci ; 15(8): 849-859, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-32734299

RESUMO

Cigarette smoking increases the likelihood of developing anxiety disorders, among them panic disorder (PD). While brain structures altered by smoking partly overlap with morphological changes identified in PD, the modulating impact of smoking as a potential confounder on structural alterations in PD has not yet been addressed. In total, 143 PD patients (71 smokers) and 178 healthy controls (62 smokers) participated in a multicenter magnetic resonance imaging (MRI) study. T1-weighted images were used to examine brain structural alterations using voxel-based morphometry in a priori defined regions of the defensive system network. PD was associated with gray matter volume reductions in the amygdala and hippocampus. This difference was driven by non-smokers and absent in smoking subjects. Bilateral amygdala volumes were reduced with increasing health burden (neither PD nor smoking > either PD or smoking > both PD and smoking). As smoking can narrow or diminish commonly observed structural abnormalities in PD, the effect of smoking should be considered in MRI studies focusing on patients with pathological forms of fear and anxiety. Future studies are needed to determine if smoking may increase the risk for subsequent psychopathology via brain functional or structural alterations.


Assuntos
Encéfalo/diagnóstico por imagem , Fumar Cigarros/patologia , Transtorno de Pânico/diagnóstico por imagem , Adulto , Encéfalo/patologia , Estudos de Casos e Controles , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão/fisiologia , Transtorno de Pânico/patologia , Adulto Jovem
7.
Depress Anxiety ; 31(10): 843-50, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24390875

RESUMO

BACKGROUND: Neurosteroids are synthesized both in brain and peripheral steroidogenic tissue from cholesterol or steroidal precursors. Neurosteroids have been shown to be implicated in neural proliferation, differentiation, and activity. Preclinical and clinical studies also suggest a modulatory role of neurosteroids in anxiety-related phenotypes. However, little is known about the contribution of genetic variants in genes relevant for the neurosteroidogenesis to anxiety disorders. METHODS: We performed an association analysis of single nucleotide polymorphisms (SNPs) in five genes related to the neurosteroidal pathway with emphasis on progesterone and allopregnanolone biosynthesis (steroid-5-alpha-reductase 1A (SRD5A1), aldo-keto reductase family 1 C1-C3 (AKR1C1-AKR1C3) and translocator protein 18 kDA (TSPO) with panic disorder (PD) and dimensional anxiety in two German PD samples (cases N = 522, controls N = 1,115). RESULTS: Case-control analysis for PD and SNPs in the five selected genes was negative in the combined sample. However, we detected a significant association of anticipatory anxiety with two intronic SNPs (rs3930965, rs41314625) located in the gene AKR1C1 surviving correction for multiple testing in PD patients. Stratification analysis for gender revealed a female-specific effect of the associations of both SNPs. CONCLUSIONS: These results suggest a modulatory effect of AKR1C1 activity on anxiety levels, most likely through changes in progesterone and allopregnanolone levels within and outside the brain. In summary, this is the first evidence for the gender-specific implication of the AKR1C1 gene in the expression of anticipatory anxiety in PD. Further analyses to unravel the functional role of the SNPs detected here and replication analyses are needed to validate our results.


Assuntos
20-Hidroxiesteroide Desidrogenases/genética , Ansiedade/genética , Transtorno de Pânico/genética , Pregnanolona/metabolismo , Progesterona/metabolismo , 3-Hidroxiesteroide Desidrogenases/genética , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Adulto , Membro C3 da Família 1 de alfa-Ceto Redutase , Ansiedade/metabolismo , Ansiedade/psicologia , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Hidroxiprostaglandina Desidrogenases/genética , Hidroxiesteroide Desidrogenases/genética , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Transtorno de Pânico/metabolismo , Transtorno de Pânico/psicologia , Polimorfismo de Nucleotídeo Único , Receptores de GABA/genética , Fatores Sexuais
8.
Eur Arch Psychiatry Clin Neurosci ; 262(4): 329-39, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22006639

RESUMO

The connection between cholinergic transmission and cognitive performance has been established in behavioural studies. The specific contribution of the muscarinic receptor system on cognitive performance and brain activation, however, has not been evaluated satisfyingly. To investigate the specific contribution of the muscarinic transmission on neural correlates of working memory, we examined the effects of scopolamine, an antagonist of the muscarinic receptors, using functional magnetic resonance imaging (fMRI). Fifteen healthy male, non-smoking subjects performed a fMRI scanning session following the application of scopolamine (0.4 mg, i.v.) or saline in a placebo-controlled, repeated measure, pseudo-randomized, single-blind design. Working memory was probed using an n-back task. Compared to placebo, challenging the cholinergic transmission with scopolamine resulted in hypoactivations in parietal, occipital and cerebellar areas and hyperactivations in frontal and prefrontal areas. These alterations are interpreted as compensatory strategies used to account for downregulation due to muscarinic acetylcholine blockade in parietal and cerebral storage systems by increased activation in frontal and prefrontal areas related to working memory rehearsal. Our results further underline the importance of cholinergic transmission to working memory performance and determine the specific contribution of muscarinic transmission on cerebral activation associated with executive functioning.


Assuntos
Imageamento por Ressonância Magnética/métodos , Memória de Curto Prazo , Receptores Muscarínicos/fisiologia , Escopolamina/farmacologia , Adulto , Regulação para Baixo/fisiologia , Função Executiva/efeitos dos fármacos , Função Executiva/fisiologia , Humanos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Memória de Curto Prazo/fisiologia , Antagonistas Muscarínicos/farmacologia , Testes Neuropsicológicos , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/fisiologia , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia , Método Simples-Cego , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
9.
Psychiatry Res ; 194(1): 95-104, 2011 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-21827965

RESUMO

Behavioral and electrophysiological data indicate compromised stimulus suppression in schizophrenia. The physiological basis of this effect and its contributions to the etiology of the disease are poorly understood. We examined neural and metabolic measures of P50 suppression in 12 patients with schizophrenia and controls. First, whole-head magnetoencephalography (MEG) assessed amplitudes of left- and right-hemispheric evoked responses and induced oscillations. Secondly, functional magnetic resonance imaging (fMRI) measured the hemodynamic responses to pairs of beeps with a short interval (500ms) as compared with those with a long interval (1500ms). The suppression of alpha power (8-13Hz) time-locked to the stimuli was negatively correlated with the suppression of evoked components and the hemodynamic measures. Remarkably, the suppression of alpha power was reduced in the patients already prior to stimulus onset. Conceivably, alpha oscillations play a central role in stimulus adaptation of neuronal networks and reflect an active mechanism for sensory suppression. The reduced stimulus suppression in schizophrenia seems to be in part due to impaired generation of alpha oscillations in the auditory cortex, resulting in higher metabolic demand as detected by fMRI. Delayed recovery of alpha rhythm may reflect an impaired gating function and contribute to sensory and cognitive deficits in schizophrenia.


Assuntos
Relógios Biológicos/fisiologia , Encéfalo/fisiopatologia , Potenciais Evocados Auditivos/fisiologia , Hemodinâmica/fisiologia , Esquizofrenia/fisiopatologia , Estatística como Assunto , Estimulação Acústica , Adolescente , Adulto , Encéfalo/irrigação sanguínea , Eletroencefalografia , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Magnetoencefalografia , Masculino , Oxigênio/sangue , Esquizofrenia/patologia , Fatores de Tempo , Adulto Jovem
10.
Phytother Res ; 24(10): 1549-53, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20878709

RESUMO

Plant extracts such as Hypericum perforatum and Pycnogenol have been tested as alternatives to the classical ADHD drugs. It has been possible to describe neuroprotective effects of such plant extracts. A reduction of ADHD symptoms could be shown in clinical studies after the application of Pycnogenol, which is a pine bark extract. The impacts of the standardized herbal extracts Hypericum perforatum, Pycnogenol and Enzogenol up to a concentration of 5000 ng/mL on cell survival and energy metabolism in human SH-SY5Y neuroblastoma cells has been investigated in the present examination. Hypericum perforatum significantly decreased the survival of cells after treatment with a concentration of 5000 ng/mL, whereas lower concentrations exerted no significant effects. Pycnogenol( induced a significant increase of cell survival after incubation with a concentration of 32.25 ng/mL and a concentration of 250 ng/mL. Other applied concentrations of Pycnogenol failed to exert significant effects. Treatment with Enzogenol did not lead to significant changes in cell survival.Concerning energy metabolism, the treatment of cells with a concentration of 5000 ng/mL Hypericum perforatum led to a significant increase of ATP levels, whereas treatment with a concentration of 500 ng/mL had no significant effect. Incubation of cells with Pycnogenol and Enzogenol exerted no significant effects.None of the tested substances caused any cytotoxic effect when used in therapeutically relevant concentrations.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Metabolismo Energético , Flavonoides/farmacologia , Hypericum/química , Extratos Vegetais/farmacologia , Quercetina/análogos & derivados , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Fitoterapia , Quercetina/farmacologia
11.
J Neural Transm (Vienna) ; 117(6): 793-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20467764

RESUMO

Oxidative DNA damage as one sign of reactive oxygen species induced oxidative stress is an important factor in the pathogenesis of various psychiatric disorders. Altered levels of DNA base damage products as well as the expression of the main repair enzyme 8-hydroxyguanine glycosylase 1 have been described. The aim of the present study was to examine the effects of drugs (amphetamine, methylphenidate and atomoxetine) used in the treatment of attention deficit-hyperactivity disorder on the expression of this enzyme via reverse transcriptase-polymerase chain reaction in human neuroblastoma SH-SY5Y and human monocytic U-937 cells at concentrations of 50, 500 and 5,000 ng/ml. We observed decreased expression of this enzyme for all applied substances. In U-937 cells, the significance level was reached after treatment with 5,000 ng/ml amphetamine as well as after treatment with 50, 500 and 5,000 ng/ml atomoxetine. Incubation of SH-SY5Y cells with 50 and 5,000 ng/ml amphetamine and 5,000 ng/ml methylphenidate led to significant decreases of 8-hydroxyguanine glycosylase 1. As a positive correlation between the expression of 8-hydroxyguanine glycosylase 1 and the level of oxidative DNA damage products has been described, we accordingly consider these substances (amphetamine, methylphenidate and atomoxetine) to possibly play a protective role in this process.


Assuntos
Inibidores da Captação Adrenérgica/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , DNA Glicosilases/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Propilaminas/farmacologia , Anfetamina/farmacologia , Cloridrato de Atomoxetina , Linhagem Celular , DNA Glicosilases/genética , Relação Dose-Resposta a Droga , Humanos , Metilfenidato/farmacologia , Monócitos/citologia , Neuroblastoma , RNA Mensageiro/metabolismo
12.
J Behav Ther Exp Psychiatry ; 40(3): 468-78, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19589499

RESUMO

Questionnaires for the assessment of depression benefit from modern test construction like item-response-modelling. We developed two parallel 10 item depression questionnaires, the Rasch-based Depression Screening version 1 (DESC-I) and 2 (DESC-II), by combining Rasch analysis and structural equation modelling on patient samples suffering primarily from a mental disorder or from somatic diseases. Both scales base upon a Rasch homogeneous item bank and proved unidimensionality and good model fit. Cut-off scores with good sensitivity and specificity were developed using ROC analyses. Results suggest that DESC may be appropriately used to screen for depression and may be beneficial for repeated measurements.


Assuntos
Depressão/diagnóstico , Modelos Estatísticos , Escalas de Graduação Psiquiátrica , Inquéritos e Questionários , Adulto , Feminino , Humanos , Entrevista Psicológica , Modelos Logísticos , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Curva ROC , Sensibilidade e Especificidade
13.
Bipolar Disord ; 7(3): 292-7, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15898968

RESUMO

OBJECTIVE: We report on a rare case of Hashimoto's encephalopathy associated with a bipolar affective disorder. CASE REPORT: A 32-year-old woman presented with a bipolar affective disorder and Hashimoto's thyroiditis. Neurological investigations (magnetic resonance imaging of the brain and cerebrospinal fluid) did not reveal any pathological findings except for a pathological electroencephalogram (EEG). Despite consequent antidepressant treatment, the patient remitted only in conjunction with normalization of the EEG after short-term treatment with high doses of prednisolone. CONCLUSION: In treatment resistant courses of disorders, the thorough clinical and laboratory investigation of our patient revealed a very efficient treatment strategy. Cases of Hashimoto's encephalopathy associated with the occurrence of a manic episode and hence with bipolar disorder are rare; this is the first reported case. However, clinicians should be alert to this possibility.


Assuntos
Transtorno Bipolar/diagnóstico , Tireoidite Autoimune/diagnóstico , Adulto , Eletroencefalografia , Feminino , Humanos , Prednisolona/uso terapêutico , Tireoidite Autoimune/terapia
14.
Am J Psychiatry ; 161(2): 294-304, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14754779

RESUMO

OBJECTIVE: Mismatch negativity is an event-related brain response sensitive to deviations within a sequence of repetitive auditory stimuli. It is thought to reflect short-term sensory memory and is independent of higher-level cognitive processes. Mismatch negativity response is diminished in patients with schizophrenia. Little is known about the mechanisms of this decreased response, the contribution of the different hemispheres, and its locus of generation. METHOD: Patients with schizophrenia (N=12) and matched comparison subjects (N=12) were studied. A novel design to measure mismatch negativity responses to deviant auditory stimuli was generated by using the switching noises from the functional magnetic resonance imaging (fMRI) scanner, thus avoiding any interfering background sound. Stimuli included deviants of amplitude (9 dB lower) and duration (76 msec shorter) presented in a random sequence. The scanner noise was recorded and applied to the same subjects in a whole-head magnetoencephalography (MEG) device. Neuromagnetic and hemodynamic responses to the identical stimuli were compared between the patients and comparison subjects. RESULTS: As expected, neuromagnetic mismatch fields were smaller in the patient group. More specifically, a lateralization to the right for duration deviance was only found in comparison subjects. For the relative amplitude of the blood-oxygen-level-dependent signal (measured with fMRI), differences emerged in the secondary (planum temporale), but not primary (Heschl's gyrus), auditory cortex. Duration deviants achieved a right hemispheric advantage only in the comparison group. A significantly stronger lateralization to the left was found for the deviant amplitude stimuli in the patients. CONCLUSIONS: The data support the view of altered hemispheric interactions in the formation of the short-term memory traces necessary for the integration of auditory stimuli. This process is predominantly mediated by the planum temporale (secondary auditory cortex). Altered interaction of regions within the superior temporal plane and across hemispheres could be in part responsible for language-mediated cognitive (e.g., verbal memory) and psychopathological (hallucinations, formal thought disorder) symptoms in schizophrenia.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Imageamento por Ressonância Magnética , Magnetoencefalografia , Oxigênio/metabolismo , Esquizofrenia/metabolismo , Adulto , Manual Diagnóstico e Estatístico de Transtornos Mentais , Potenciais Evocados Auditivos/fisiologia , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Variações Dependentes do Observador , Oxigênio/sangue , Esquizofrenia/diagnóstico , Esquizofrenia/epidemiologia
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