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1.
Br J Psychiatry ; 194(1): 25-33, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19118321

RESUMO

BACKGROUND: People with prodromal symptoms have a very high risk of developing psychosis. AIMS: To use functional magnetic resonance imaging to examine the neurocognitive basis of this vulnerability. METHOD: Cross-sectional comparison of regional activation in individuals with an'at-risk mental state' (at-risk group: n=17), patients with first-episode schizophreniform psychosis (psychosis group: n=10) and healthy volunteers (controls: n=15) during an overt verbal fluency task and an N-back working memory task. RESULTS: A similar pattern of between-group differences in activation was evident across both tasks. Activation in the at-risk group was intermediate relative to that in controls and the psychosis group in the inferior frontal and anterior cingulate cortex during the verbal fluency task and in the inferior frontal, dorsolateral prefrontal and parietal cortex during the N-back task. CONCLUSIONS: The at-risk mental state is associated with abnormalities of regional brain function that are qualitatively similar to, but less severe than, those in patients who have recently presented with psychosis.


Assuntos
Transtornos da Memória/fisiopatologia , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Estudos de Casos e Controles , Estudos Transversais , Feminino , Giro do Cíngulo/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Transtornos Psicóticos/tratamento farmacológico , Fatores de Risco , Resultado do Tratamento , Comportamento Verbal , Adulto Jovem
2.
Br J Psychiatry ; 194(6): 527-34, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19478293

RESUMO

BACKGROUND: Subtle abnormalities in frontal white matter have been reported in bipolar disorder. AIMS: To assess whether impaired integrity of white matter tracts is associated with bipolar disorder and genetic liability for the disorder. METHOD: A total of 19 patients with psychotic bipolar I disorder from multiply affected families, 21 unaffected first-degree relatives and 18 comparison individuals (controls) underwent diffusion tensor imaging. Whole brain voxel-based analyses compared fractional anisotropy between patients and relatives with controls, and its relationship with a quantitative measure of genetic liability. RESULTS: Patients had decreased fractional anisotropy compared with controls in the genu of the corpus callosum, right inferior longitudinal fasciculus and left superior longitudinal fasciculus. Increased genetic liability for bipolar disorder was associated with reduced fractional anisotropy across distributed regions of white matter in patients and their unaffected relatives. CONCLUSIONS: Disturbed structural integrity within key intra- and interhemispheric tracts characterises both bipolar disorder and genetic liability for this illness.


Assuntos
Transtorno Bipolar/genética , Transtorno Bipolar/patologia , Encéfalo/patologia , Adulto , Anisotropia , Estudos de Casos e Controles , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Linhagem
3.
Brain ; 131(Pt 1): 205-17, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18056158

RESUMO

Very preterm (VPT) birth is associated with altered cortical development and long-term neurodevelopmental sequelae. We used voxel-based morphometry to investigate white (WM) and grey matter (GM) distribution in VPT adolescents and controls, and the association with gestational age and neonatal ultrasound findings in the VPT individuals. GM and WM volumes were additionally investigated in relation to adolescent neurodevelopmental outcome. Structural MRI data were acquired with a 1.5 Tesla machine in 218 VPT adolescents (<33 weeks, gestation) and 128 controls aged 14-15 years, and analysed using SPM2 software. VPT individuals compared to controls showed reduced GM in temporal, frontal, occipital cortices and cerebellum, including putamen, insula, cuneus, fusiform gyrus, thalamus and caudate nucleus, and increased GM predominantly in temporal and frontal lobes, including cingulate and fusiform gyri and cerebellum. WM loss was concentrated in the brainstem, internal capsule, temporal and frontal regions and the major fasciculi. WM excesses were observed in temporal, parietal and frontal regions. Investigation of the inter-relationships between brain regions and changes revealed that all selected areas where between-group increased and decreased WM and GM volumes differences were observed, were structurally associated, highlighting the influence that abnormalities in one brain area may exert over others. VPT individuals with evidence of periventricular haemorrhage and ventricular dilatation on neonatal ultrasound exhibited the greatest WM and GM alterations. VPT adolescents obtained lower scores than controls on measures of language and executive function and were more likely to show cognitive impairment compared to controls (27% versus 14%, respectively). Several areas where VPT individuals demonstrated decreased GM and WM volume were linearly associated with gestational age and mediated cognitive impairment. To summarize, our data demonstrates that VPT birth is associated with altered brain structure in adolescence. GM and WM alterations are associated with length of gestation and mediate adolescent neurodevelopmental impairment. Thus, anatomical brain changes may contribute to specific cognitive deficits associated with VPT birth and could be used in the identification of those individuals who may be at increased risk for cognitive impairment.


Assuntos
Encéfalo/crescimento & desenvolvimento , Recém-Nascido Prematuro , Adolescente , Antropometria , Peso ao Nascer , Encéfalo/patologia , Hemorragia Cerebral/diagnóstico por imagem , Estudos de Coortes , Ecoencefalografia , Feminino , Idade Gestacional , Humanos , Imageamento Tridimensional/métodos , Recém-Nascido , Doenças do Prematuro/diagnóstico por imagem , Desenvolvimento da Linguagem , Imageamento por Ressonância Magnética/métodos , Masculino , Memória , Plasticidade Neuronal , Testes Neuropsicológicos
4.
Biol Psychiatry ; 61(10): 1148-56, 2007 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-17098213

RESUMO

BACKGROUND: Individuals with an At Risk Mental State (ARMS) have a very high risk of developing a psychotic disorder but the basis of this risk is unclear. We addressed this issue by studying gray matter volume in this group with magnetic resonance imaging (MRI). METHODS: Thirty-five individuals with an ARMS, 25 patients with first episode schizophrenia, and 22 healthy volunteers were studied using a 1.5T MRI scanner. Twelve (34%) of the ARMS group developed schizophrenia in the 2 years subsequent to scanning. RESULTS: There were significant volumetric differences between the three groups in the left insula, superior temporal gyrus, cingulate gyrus and precuneus. In these regions, the volume in the ARMS group was smaller than in volunteers but not significantly different from that in the first episode (FE) group. Direct comparison of the ARMS and control groups revealed additional areas of reduced volume in the left medial temporal cortex. Within the ARMS group, those subjects who later developed psychosis had less gray matter than subjects who did not in the right insula, inferior frontal and superior temporal gyrus. CONCLUSIONS: The ARMS was associated with reductions in gray matter volume in areas that are also reduced in schizophrenia, suggesting that these are a correlate of an increased vulnerability to psychosis. Volumetric differences within the ARMS group may be related to the subsequent onset of schizophrenia in a subset of those at high risk.


Assuntos
Encéfalo/patologia , Predisposição Genética para Doença/genética , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Esquizofrenia/genética , Psicologia do Esquizofrênico , Transtorno da Personalidade Esquizotípica/genética , Adolescente , Adulto , Córtex Cerebral/patologia , Dominância Cerebral/fisiologia , Diagnóstico Precoce , Feminino , Seguimentos , Giro do Cíngulo/patologia , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Valores de Referência , Risco , Esquizofrenia/diagnóstico , Transtorno da Personalidade Esquizotípica/diagnóstico
5.
Am J Psychiatry ; 164(3): 467-73, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17329472

RESUMO

OBJECTIVE: Cognitive models propose that the symptoms and psychological impairments associated with schizophrenia arise as a consequence of impaired communication between brain regions, especially the prefrontal cortex and the temporal and parietal lobes. Functional imaging and electrophysiological data have provided evidence of functional dysconnectivity, but it is unclear whether this reflects an underlying problem with anatomical connectivity. This study used diffusion tensor imaging to examine the integrity of the major white matter fasciculi, which connects the frontal and temporal-parietal cortices, and the corpus callosum in patients with schizophrenia. METHOD: A 1.5-T magnetic resonance scanner was used to acquire diffusion tensor images giving whole brain coverage at an isotropic 2.5-mm voxel size. Fractional anisotropy was measured in 33 patients with schizophrenia and 40 healthy comparison subjects with an automated voxel-based method of analysis. RESULTS: There was reduced fractional anisotropy in patients with schizophrenia in regions corresponding to the superior longitudinal fasciculi bilaterally and in the genu of the corpus callosum. However, within the patient group, the propensity to experience auditory hallucinations was associated with relatively increased fractional anisotropy in superior longitudinal fasciculi and in the anterior cingulum. CONCLUSIONS: Schizophrenia is associated with altered white matter integrity in the tracts connecting the frontal cortex with the temporal and parietal cortices and with the contralateral frontal and temporal lobes. The severity of these changes may vary with the pattern of symptoms associated with the disorder.


Assuntos
Córtex Cerebral/fisiopatologia , Imagem de Difusão por Ressonância Magnética/estatística & dados numéricos , Vias Neurais/patologia , Córtex Pré-Frontal/patologia , Esquizofrenia/diagnóstico , Esquizofrenia/patologia , Adulto , Anisotropia , Mapeamento Encefálico , Córtex Cerebral/metabolismo , Corpo Caloso/patologia , Feminino , Lateralidade Funcional/fisiologia , Alucinações/diagnóstico , Alucinações/metabolismo , Alucinações/patologia , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Vias Neurais/metabolismo , Lobo Parietal/patologia , Córtex Pré-Frontal/metabolismo , Esquizofrenia/metabolismo , Psicologia do Esquizofrênico , Índice de Gravidade de Doença , Lobo Temporal/metabolismo , Lobo Temporal/patologia
6.
Neuroreport ; 18(5): 473-7, 2007 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-17496806

RESUMO

Depersonalization disorder, characterized by emotional detachment, has been associated with increased prefrontal cortical and decreased autonomic activity to emotional stimuli. Event-related fMRI with simultaneous measurements of skin conductance levels occurred in nine depersonalization disorder patients and 12 normal controls to neutral, mild and intense happy and sad facial expressions. Patients, but not controls, showed decreases in subcortical limbic activity to increasingly intense happy and sad facial expressions, respectively. For both happy and sad expressions, negative correlations between skin conductance measures in bilateral dorsal prefrontal cortices occurred only in depersonalization disorder patients. Abnormal decreases in limbic activity to increasingly intense emotional expressions, and increases in dorsal prefrontal cortical activity to emotionally arousing stimuli may underlie the emotional detachment of depersonalization disorder.


Assuntos
Depressão , Emoções/fisiologia , Expressão Facial , Sistema Límbico/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Adulto , Mapeamento Encefálico , Depressão/patologia , Depressão/fisiopatologia , Depressão/psicologia , Feminino , Resposta Galvânica da Pele/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Sistema Límbico/irrigação sanguínea , Imageamento por Ressonância Magnética/métodos , Masculino , Oxigênio/sangue , Estimulação Luminosa/métodos , Córtex Pré-Frontal/irrigação sanguínea
7.
Brain ; 129(Pt 5): 1218-28, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16569671

RESUMO

In people with velo-cardio-facial syndrome [or 22q11.2 deletion syndrome (22qDS)], a single interstitial deletion of chromosome 22q11.2 causes a wide spectrum of cognitive deficits ranging from global learning difficulties to specific cognitive deficits. People with 22qDS are also at high risk of developing attention-deficit/hyperactivity disorder and autism spectrum disorders in childhood, and schizophrenia in adolescence or adult life. However, the neurobiology of 22qDS, and the relationship between abnormalities in brain anatomy and behaviour, is poorly understood. Thus, we studied the neuroanatomy of 22qDS children using fully automated voxel-based morphometry (VBM) and manually traced single region-of-interest (ROI) analysis. Also, we investigated whether those brain regions that differed significantly between groups were related to behavioural differences within children with 22qDS. We compared the brain morphometry of 39 children and adolescents with 22qDS (mean age: 11 years, SD +/-3, IQ = 67, SD +/-10) and 26 sibling controls (mean age: 11 years, SD +/-3, IQ = 102, SD +/-12). Using VBM, we found, after correction for IQ, that individuals with 22qDS compared with controls had a significant reduction in cerebellar grey matter, and white matter reductions in the frontal lobe, cerebellum and internal capsule. Using single ROI analysis, we found that people with 22qDS had a significant (P < 0.05) reduction in bulk volume bilaterally in the occipital-parietal lobes, but a larger right caudate nucleus and lateral ventricles. Further, within people with 22qDS, there was a significant positive correlation between severity of (i) schizotypy score and grey matter volume of the temporo-occipital regions and the corpus striatum; (ii) emotional problems and grey matter volume of frontostriatal regions; and (iii) social behavioural difficulties and grey matter in frontostriatal regions. Thus, subjects with 22qDS have widespread changes in brain anatomy, particularly affecting white matter, basal ganglia and cerebellum. Also, within 22qDS, regionally specific differences in brain development may partially underpin behavioural differences. We suggest that there is preliminary evidence for specific vulnerability of the frontostriatal and cerebellar-cortical networks in 22qDS.


Assuntos
Encéfalo/patologia , Transtornos do Comportamento Infantil/etiologia , Síndrome de DiGeorge/patologia , Adolescente , Gânglios da Base/patologia , Mapeamento Encefálico/métodos , Cerebelo/patologia , Criança , Transtornos do Comportamento Infantil/patologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/patologia , Síndrome de DiGeorge/genética , Síndrome de DiGeorge/psicologia , Feminino , Lobo Frontal/patologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Psicometria , Transtorno da Personalidade Esquizotípica/etiologia , Transtorno da Personalidade Esquizotípica/patologia
8.
Psychiatry Res ; 156(1): 15-21, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17720459

RESUMO

Schizophrenia is characterised by the presence of a heterogeneous range of symptoms. Although there is a consensus regarding ventricular enlargement and regional grey matter deficits, the brain structural correlates of specific symptoms, such as auditory hallucinations, are not clearly defined. We used an automated voxel-wise analysis of dual-echo spin-echo MRI data from 28 patients with schizophrenia characterised by persistent hallucinations and 32 healthy controls. Patients demonstrated grey matter (GM) volume decrements in the insula bilaterally, and in the right superior temporal and fusiform gyri, and left inferior temporal gyrus. With the exception of the insula, these GM volume losses were correlated with severity of auditory hallucinations. GM excesses were observed in the right caudate nucleus and middle temporal gyrus. White matter deficits were observed adjacent to the left superior temporal gyrus, in the right internal capsule and inferior longitudinal fasciculus. These findings support the proposition that there are structural changes in the neural circuits underlying broader processing of affect-laden information in patients with schizophrenia prone to experiencing auditory hallucinations. Such deficits may obscure important cues for recognition of internal speech, contributing to failures of self-monitoring.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiopatologia , Alucinações/epidemiologia , Esquizofrenia/epidemiologia , Esquizofrenia/fisiopatologia , Adulto , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/fisiopatologia , Feminino , Lateralidade Funcional/fisiologia , Alucinações/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Masculino , Lobo Temporal/anatomia & histologia , Lobo Temporal/fisiopatologia
9.
Br J Psychiatry Suppl ; 51: s123-7, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18055928

RESUMO

BACKGROUND: First-episode psychosis is typically preceded by a prodrome in which there is deterioration in global and social functioning. AIMS: To examine whether the duration of the prodromal phase influences grey and white matter volumes at the onset of psychosis. METHODS: Eighty-two people were scanned using magnetic resonance imaging when they developed a first episode of psychosis. The duration of the prodromal phase was estimated from detailed interviews and medical records. Voxel-based morphometry was used to assess neuroanatomical abnormalities. RESULTS: A long prodromal phase was associated with smaller grey matter volumes in the cingulate, frontal and left insular cortex, and with less white matter volume bilaterally in the superior longitudinal and uncinate fasciculi and the cingulum. CONCLUSIONS: The severity of volumetric abnormalities in first-episode psychosis was greater in those with a long prodrome.


Assuntos
Encéfalo/patologia , Transtornos Psicóticos/patologia , Transtorno da Personalidade Esquizotípica/patologia , Adolescente , Adulto , Mapeamento Encefálico/métodos , Córtex Cerebral/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Esquizofrenia/patologia , Fatores de Tempo
10.
Br J Psychiatry Suppl ; 51: s111-6, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18055926

RESUMO

BACKGROUND: Grey matter and other structural brain abnormalities are consistently reported in first-onset schizophrenia, but less is known about the extent of neuroanatomical changes in first-onset affective psychosis. AIMS: To determine which brain abnormalities are specific to (a) schizophrenia and (b) affective psychosis. METHOD: We obtained dual-echo (proton density/T2-weighted) magnetic resonance images and carried out voxel-based analysis on the images of 73 patients with first-episode psychosis (schizophrenia n=44, affective psychosis n=29) and 58 healthy controls. RESULTS: Both patients with schizophrenia and patients with affective psychosis had enlarged lateral and third ventricle volumes. Regional cortical grey matter reductions (including bilateral anterior cingulate gyrus, left insula and left fusiform gyrus) were evident in affective psychosis but not in schizophrenia, although patients with schizophrenia displayed decreased hippocampal grey matter and increased striatal grey matter at a more liberal statistical threshold. CONCLUSIONS: Both schizophrenia and affective psychosis are associated with volumetric abnormalities at the onset of frank psychosis, with some of these evident in common brain areas.


Assuntos
Transtornos Psicóticos Afetivos/patologia , Encéfalo/patologia , Esquizofrenia/patologia , Adolescente , Adulto , Transtornos Psicóticos Afetivos/tratamento farmacológico , Idoso , Antipsicóticos/administração & dosagem , Mapeamento Encefálico/métodos , Córtex Cerebral/patologia , Ventrículos Cerebrais/patologia , Esquema de Medicação , Feminino , Giro do Cíngulo/patologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esquizofrenia/tratamento farmacológico , Fatores de Tempo
11.
Biol Psychiatry ; 59(3): 273-83, 2006 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-16139817

RESUMO

BACKGROUND: Women with Turner syndrome (TS; 45,X) lack a normal second X chromosome, and many are prescribed exogenous sex and growth hormones (GH). Hence, they allow us an opportunity to investigate genetic and endocrine influences on brain development. METHODS: We examined brain anatomy and metabolism in 27 adult monosomic TS women and 21 control subjects with volumetric magnetic resonance imaging and magnetic resonance spectroscopy. RESULTS: In TS women, regional gray matter volume was significantly smaller in parieto-occipital cortex and caudate nucleus and larger in cerebellar hemispheres. White matter was reduced in the cerebellar hemispheres, parieto-occipital regions, and splenium of the corpus callosum but was increased in the temporal and orbitofrontal lobes and genui of corpus callosum. Women with TS had a significantly lower parietal lobe concentration of N-acetyl aspartate, and higher hippocampal choline. Also, among women with TS, there were significant differences in regional gray matter volumes and/or neuronal integrity, depending upon parental origin of X chromosome and oxandrolone and GH use. CONCLUSIONS: X chromosome monosomy, imprinting and neuroendocrine milieu modulate human brain development-perhaps in a regionally specific manner.


Assuntos
Encéfalo/patologia , Cromossomos Humanos X/fisiologia , Hormônios Esteroides Gonadais/uso terapêutico , Hormônio do Crescimento Humano/uso terapêutico , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Síndrome de Turner/fisiopatologia , Adulto , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Encéfalo/efeitos dos fármacos , Colina/metabolismo , Feminino , Humanos , Recém-Nascido , Monossomia/genética , Oxandrolona/uso terapêutico , Síndrome de Turner/tratamento farmacológico , Síndrome de Turner/genética
12.
Schizophr Res ; 83(2-3): 145-53, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16448803

RESUMO

PURPOSE: A long duration of untreated psychosis (DUP) is associated with relatively poor clinical and social outcomes. In order to identify whether an anatomically mediated mechanism may give rise to poorer outcomes, it is important to identify whether a long DUP is associated with greater brain structural abnormalities. METHOD: 81 patients with first-episode psychosis (schizophrenia, affective, and other psychoses) were scanned using high resolution Magnetic Resonance Imaging. DUP was defined as the number of days between first onset of psychotic symptoms and first contact with mental health services. High-resolution MRI images and voxel-based methods of image analysis were used to investigate brain structure in these patients. RESULTS: Longer DUP was associated with gray matter reductions in left middle and inferior temporal, left occipital and left fusiform cortices, and with gray matter excess of the left basal ganglia. All findings remained significant when co-varying for exposure to antipsychotic treatment. CONCLUSIONS: Temporal gray matter reductions are more marked in patients with a long DUP. This could reflect a progressive pathological process that is active prior to treatment. Alternatively, these abnormalities could be associated with a more insidious onset of illness and a later presentation to services.


Assuntos
Encéfalo/anormalidades , Encéfalo/patologia , Transtornos Psicóticos/patologia , Adolescente , Adulto , Idoso , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Transtornos Psicóticos/classificação , Estudos Retrospectivos , Fatores de Tempo
13.
Biol Psychiatry ; 57(8): 947-50, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15820719

RESUMO

BACKGROUND: Schizophrenia may involve dysfunction to primary auditory, speech, and language processes governed by the superior temporal gyrus (STG). These processes are implicated in hallucinations, delusions, and thought disorder. The current study explored the relationship between unreality symptoms (hallucinations and delusions) and specific STG substructures, including Heschl's gyrus (HG) and planum temporale (PT). METHODS: Twenty-five right-handed men within their first episode of psychosis were assessed using the Positive and Negative Syndrome Scale (PANSS) for the presence of hallucinations and delusional behavior (a composite score of delusions, grandiosity, suspiciousness, and unusual thought content). T1-weighted magnetic resonance imaging (MRI) scans were acquired using a 1.5 Tesla scanner. Stereological measurements of HG and PT volume were obtained. Linear regression methods explored the relationship between regional volumes and symptoms. RESULTS: Reductions in left HG were associated with hallucinations and delusions. Increases in left PT were associated with delusional behavior. CONCLUSIONS: Current results implicate HG dysfunction in unreality symptoms in men with recent-onset schizophrenia.


Assuntos
Psicologia do Esquizofrênico , Lobo Temporal/fisiologia , Adulto , Delusões/fisiopatologia , Delusões/psicologia , Lateralidade Funcional/fisiologia , Alucinações/fisiopatologia , Alucinações/psicologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Escalas de Graduação Psiquiátrica
14.
Biol Psychiatry ; 58(6): 479-87, 2005 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-15978549

RESUMO

BACKGROUND: Several structural magnetic resonance imaging (MRI) studies have investigated the presence of brain abnormalities in obsessive-compulsive disorder (OCD) but have not produced consistent findings. This might be partly related to their use of a regions-of-interest approach. We assessed gray matter volumes in 19 OCD subjects and 15 healthy volunteers, using voxel-based morphometry (VBM). METHODS: Images were acquired with a 1.5-T MRI scanner, spatially normalized, and segmented with optimized VBM. Statistical comparisons were performed with the general linear model. RESULTS: Significant findings were detected in regions predicted a priori to be implicated in OCD, including increased gray matter in OCD subjects relative to control subjects in posterior orbitofrontal and parahippocampal regions; decreased gray matter in OCD patients in the left anterior cingulate cortex; and inverse correlations between obsessive-compulsive symptom severity and gray matter in the medial thalamus (p < .001, uncorrected for multiple comparisons). Also, an unpredicted site of gray matter reduction in OCD patients in the right parietal associative cortex approached significance (p = .052, corrected for multiple comparisons). CONCLUSIONS: Our findings are consistent with previous studies implicating dysfunction of orbitofrontal, cingulate, thalamic, and temporolimbic regions in OCD and suggest that the involvement of the parietal cortex in the pathophysiology of OCD warrants further investigation.


Assuntos
Encéfalo/patologia , Transtorno Obsessivo-Compulsivo/patologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estatística como Assunto
15.
Neuropsychopharmacology ; 30(4): 765-74, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15702141

RESUMO

Typical antipsychotic drugs act on the dopaminergic system, blocking the dopamine type 2 (D2) receptors. Atypical antipsychotics have lower affinity and occupancy for the dopaminergic receptors, and a high degree of occupancy of the serotoninergic receptors 5-HT2A. Whether these different pharmacological actions produce different effects on brain structure remains unclear. We explored the effects of different types of antipsychotic treatment on brain structure in an epidemiologically based, nonrandomized sample of patients at the first psychotic episode. Subjects were recruited as part of a large epidemiological study (AESOP: aetiology and ethnicity in schizophrenia and other psychoses). We evaluated 22 drug-free patients, 32 on treatment with typical antipsychotics and 30 with atypical antipsychotics. We used high-resolution MRI and voxel-based methods of image analysis. The MRI analysis suggested that both typical and atypical antipsychotics are associated with brain changes. However, typicals seem to affect more extensively the basal ganglia (enlargement of the putamen) and cortical areas (reductions of lobulus paracentralis, anterior cingulate gyrus, superior and medial frontal gyri, superior and middle temporal gyri, insula, and precuneus), while atypical antipsychotics seem particularly associated with enlargement of the thalami. These changes are likely to reflect the effect of antipsychotics on the brain, as there were no differences in duration of illness, total symptoms scores, and length of treatment among the groups. In conclusion, we would like to suggest that even after short-term treatment, typical and atypical antipsychotics may affect brain structure differently.


Assuntos
Antipsicóticos/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Transtornos Psicóticos/tratamento farmacológico , Transtornos Psicóticos/patologia , Adolescente , Adulto , Idoso , Antipsicóticos/classificação , Antipsicóticos/uso terapêutico , Gânglios da Base/efeitos dos fármacos , Gânglios da Base/patologia , Encéfalo/fisiopatologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/tratamento farmacológico , Esquizofrenia/patologia , Esquizofrenia/fisiopatologia , Tálamo/efeitos dos fármacos , Tálamo/patologia , Resultado do Tratamento
16.
J Neurol ; 252(3): 321-31, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15739047

RESUMO

Cognitive dysfunction can occur in some patients with amyotrophic lateral sclerosis (ALS) who are not suffering from dementia. The most striking and consistent cognitive deficit has been found using tests of verbal fluency. ALS patients with verbal fluency deficits have shown functional imaging abnormalities predominantly in frontotemporal regions using positron emission tomography (PET). This study used automated volumetric voxel-based analysis of grey and white matter densities of structural magnetic resonance imaging (MRI) scans to explore the underlying pattern of structural cerebral change in nondemented ALS patients with verbal fluency deficits. Two groups of ALS patients, defined by the presence or absence of cognitive impairment on the basis of the Written Verbal Fluency Test (ALSi, cognitively impaired, n=11; ALSu, cognitively unimpaired n=12) were compared with healthy age matched controls (n=12). A comparison of the ALSi group with controls revealed significantly (p<0.002) reduced white matter volume in extensive motor and non-motor regions, including regions corresponding to frontotemporal association fibres. These patients demonstrated a corresponding cognitive profile of executive and memory dysfunction. Less extensive white matter reductions were revealed in the comparison of the ALSu and control groups in regions corresponding to frontal association fibres. White matter volumes were also found to correlate with performance on memory tests. There were no significant reductions in grey matter volume in the comparison of either patient group with controls. The structural white matter abnormalities in frontal and temporal regions revealed here may underlie the cognitive and functional imaging abnormalities previously reported in non-demented ALS patients. The results also suggest that extra-motor structural abnormalities may be present in ALS patients with no evidence of cognitive change. The findings support the hypothesis of a continuum of extra-motor cerebral and cognitive change in this disorder.


Assuntos
Esclerose Lateral Amiotrófica/patologia , Mapeamento Encefálico , Lobo Frontal/patologia , Lobo Temporal/patologia , Adulto , Esclerose Lateral Amiotrófica/classificação , Esclerose Lateral Amiotrófica/complicações , Esclerose Lateral Amiotrófica/metabolismo , Análise de Variância , Estudos de Casos e Controles , Feminino , Lobo Frontal/metabolismo , Humanos , Inteligência/fisiologia , Imageamento por Ressonância Magnética/métodos , Masculino , Memória/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos/estatística & dados numéricos , Tomografia por Emissão de Pósitrons/métodos , Resolução de Problemas/fisiologia , Distúrbios da Fala/etiologia , Distúrbios da Fala/metabolismo , Distúrbios da Fala/patologia , Estatística como Assunto , Lobo Temporal/metabolismo , Visão Ocular/fisiologia
17.
Arch Gen Psychiatry ; 61(10): 974-84, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15466670

RESUMO

CONTEXT: For more than a century, it has been uncertain whether or not the major diagnostic categories of psychosis--schizophrenia and bipolar disorder--are distinct disease entities with specific genetic causes and neuroanatomical substrates. OBJECTIVE: To investigate the relationship between genetic risk and structural variation throughout the entire brain in patients and their unaffected relatives sampled from multiply affected families with schizophrenia or bipolar disorder. DESIGN: Analysis of the association between genetic risk and variation in tissue volume on magnetic resonance images. SETTING: Psychiatric research center. PARTICIPANTS: Subjects comprised 25 patients with schizophrenia, 36 of their unaffected first-degree relatives, 37 patients with bipolar 1 disorder who experienced psychotic symptoms during illness exacerbation, and 50 of their unaffected first-degree relatives. MAIN OUTCOME MEASURES: We used computational morphometric techniques to map significant associations between a continuous measure of genetic liability for each subject and variation in gray or white matter volume. RESULTS: Genetic risk for schizophrenia was specifically associated with distributed gray matter volume deficits in the bilateral fronto-striato-thalamic and left lateral temporal regions, whereas genetic risk for bipolar disorder was specifically associated with gray matter deficits only in the right anterior cingulate gyrus and ventral striatum. A generic association between genetic risk for both disorders and white matter volume reduction in the left frontal and temporoparietal regions was consistent with left frontotemporal disconnectivity as a genetically controlled brain structural abnormality common to both psychotic disorders. CONCLUSIONS: Genetic risks for schizophrenia and bipolar disorder are associated with specific gray matter but generic white matter endophenotypes. Thus, Emil Kraepelin's pivotal distinction was neither wholly right nor wholly wrong: the 2 major psychoses show both distinctive and similar patterns of brain structural abnormality related to variable genetic risk.


Assuntos
Transtorno Bipolar/genética , Encéfalo/anatomia & histologia , Fenótipo , Esquizofrenia/genética , Adolescente , Adulto , Idoso , Transtorno Bipolar/diagnóstico , Saúde da Família , Feminino , Lobo Frontal/anatomia & histologia , Predisposição Genética para Doença/genética , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Análise de Regressão , Esquizofrenia/diagnóstico , Lobo Temporal/anatomia & histologia
18.
Brain ; 127(Pt 12): 2672-81, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15483045

RESUMO

Expanded trinucleotide repeats are associated with several neuropsychiatric disorders, including fragile X syndrome (FraX) which is the most common inherited form of mental retardation. It is currently thought that FraX results from having >200 CGG trinucleotide repeats, with consequent methylation of the fragile X mental retardation gene (FMR1) and loss of FMR1 protein (FMRP). Pre-mutation carriers of FraX (with 55-200 CGG trinucleotide repeats) were originally considered unaffected, although recent studies challenge this view. However, there are few studies on the effect of pre-mutation trinucleotide repeat expansion on the male human brain using quantitative MRI. Also the results of prior investigations may be confounded because people were selected on the basis of clinical and neurological features, and not genetic phenotype. We compared the brain anatomy of 20 adult male pre-mutation members of known FraX families with 20 healthy male controls. The two groups did not differ significantly in age, intelligence quotient (IQ) or handedness. We also investigated whether any observed effects were associated with: (i) ageing; (ii) expansion of pre-mutation CGG trinucleotide repeats; (iii) reduction in the percentage of lymphocytes staining with anti-FMRP antibodies [%FMRP(+) lymphocytes]; and (iv) elevation of FMR1 mRNA levels. Male pre-mutation carriers of FraX, compared with matched controls, had significantly less voxel density in several brain regions, including the cerebellum, amygdalo-hippocampal complex and thalamus. Within pre-mutation carriers of FraX, ageing, increases in the number of CGG trinucleotide repeats and decreases in %FMRP(+) lymphocytes were associated with decreasing voxel density of regions previously identified as decreased relative to controls. Regional grey and white matter density is significantly affected in male pre-mutation carriers of FraX recruited on the basis of genetic, not clinical, phenotype. The association of voxel density reduction and ageing is consistent with observations of a subgroup of older pre-mutation males who present with cognitive decline. Moreover, our findings suggest, for the first time, an association between voxel density reduction and genetic variation in FraX.


Assuntos
Encéfalo/patologia , Cromossomos Humanos X , Síndrome do Cromossomo X Frágil/genética , Heterozigoto , Repetições de Trinucleotídeos/genética , Adolescente , Adulto , Idoso , Envelhecimento/patologia , Proteína do X Frágil da Deficiência Intelectual , Síndrome do Cromossomo X Frágil/sangue , Síndrome do Cromossomo X Frágil/patologia , Expressão Gênica , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , RNA Mensageiro/genética , Proteínas de Ligação a RNA/biossíntese , Proteínas de Ligação a RNA/genética
19.
Am J Psychiatry ; 159(7): 1232-5, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12091206

RESUMO

OBJECTIVE: The nature and time course of temporal lobe abnormalities in psychotic illness remain controversial. Confounds include disease chronicity, gender, and handedness. The present study investigated temporal substructures in right-handed male patients experiencing their first episode of psychotic illness. METHOD: Magnetic resonance imaging scans were obtained for 25 minimally treated patients experiencing their first psychotic episode and 16 healthy comparison subjects. Group differences in volumes of the hippocampus, amygdala, planum temporale, and Heschl's gyrus were tested. RESULTS: The patients had smaller bilateral hippocampal and left planum temporale volumes than the comparison subjects. Paranoid and nonparanoid patients differed in left amygdala volume. CONCLUSIONS: The authors conclude that bilateral hippocampal and left planum temporale abnormalities are present near the onset of psychosis.


Assuntos
Transtornos Psicóticos/diagnóstico , Lobo Temporal/anatomia & histologia , Adulto , Tonsila do Cerebelo/anatomia & histologia , Lateralidade Funcional/fisiologia , Hipocampo/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Transtornos Psicóticos/psicologia , Esquizofrenia/diagnóstico , Esquizofrenia Paranoide/diagnóstico , Esquizofrenia Paranoide/psicologia , Psicologia do Esquizofrênico , Fatores Sexuais
20.
Am J Psychiatry ; 161(10): 1918-21, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15465994

RESUMO

OBJECTIVE: The authors investigated the structural brain correlates of antisaccade performance. METHOD: Magnetic resonance imaging was used to measure the volumes of the prefrontal, premotor, sensorimotor, and occipitoparietal cortices as well as the caudate, thalamus, cerebellar vermis, and cerebrum in 20 first-episode psychosis patients and 18 healthy comparison subjects. Antisaccades were recorded by using infrared oculography. RESULTS: Groups significantly differed in terms of antisaccade error rate and amplitude gain and tended to differ in terms of latency but not brain region volumes. Premotor cortex volume predicted antisaccade error rate among comparison subjects. In the patient group, caudate volume was related to latency and amplitude gain. Negative symptoms, independent of structural volumes, predicted error rate. CONCLUSIONS: These findings point to altered structure-function relationships in first-episode psychosis.


Assuntos
Encéfalo/anatomia & histologia , Imageamento por Ressonância Magnética , Desempenho Psicomotor/fisiologia , Movimentos Sacádicos/fisiologia , Esquizofrenia/diagnóstico , Adulto , Encéfalo/fisiopatologia , Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Feminino , Humanos , Masculino , Inibição Neural/fisiologia , Tempo de Reação/fisiologia , Análise de Regressão , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Análise e Desempenho de Tarefas , Percepção Visual/fisiologia
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