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1.
Eur Neuropsychopharmacol ; 29(12): 1408-1418, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31708330

RESUMO

Patients who have recently experienced a first of episode psychosis (FEP) exhibit considerable heterogeneity in subcortical brain volumes. These results become even more divergent when exploring the effect of antipsychotic medication among other clinical and cognitive features. We aimed to contrast volumetric measures in basal ganglia and thalamus in patients with a FEP treated with different second-generation antipsychotics. T1-weighted magnetic resonance images were obtained and subcortical structures were extracted with MAGeT-Brain. Relationships with cognitive functioning were also explored with a Global Cognitive Index obtained, on average, within one month from the scan. Subgroups included: risperidone (n = 26), aripiprazole (n = 22), olanzapine (n = 19) and controls (n = 80). The olanzapine subgroup displayed significant enlargement of the right globus pallidus volume compared with all other groups. Moreover, despite not exhibiting poorer cognitive capacity than the rest of patients, results from a stepwise multiple-regression linear regression analysis identified a significant negative association between right globus pallidus volume and scores on the Global Cognitive Index among these patients. To our knowledge, this is the first study to associate treatment with olanzapine with an increase in globus pallidus volume in a sample of FEP patients with a relatively short time of antipsychotic monotherapy. Such enlargement was also found to be associated with poorer global cognitive functioning. Exploration of the biological underpinnings of this early medication-induced enlargement should be the focus of future investigations since it may lend insight towards achieving a better clinical outcome for these patients.


Assuntos
Antipsicóticos/uso terapêutico , Gânglios da Base/efeitos dos fármacos , Gânglios da Base/diagnóstico por imagem , Transtornos Psicóticos/diagnóstico por imagem , Tálamo/efeitos dos fármacos , Tálamo/diagnóstico por imagem , Adolescente , Adulto , Antipsicóticos/farmacologia , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética/métodos , Masculino , Transtornos Psicóticos/tratamento farmacológico , Adulto Jovem
2.
Schizophr Res ; 204: 245-252, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30150023

RESUMO

BACKGROUND: The relationship between poor insight and less favorable outcomes in schizophrenia has promoted research efforts to understand its neurobiological basis. Thus far, research on neural correlates of insight has been constrained by small samples, incomplete insight assessments, and a focus on frontal lobes. The purpose of this study was to examine associations of cortical thickness and subcortical volumes, with a comprehensive assessment of clinical insight, in a large sample of enduring schizophrenia patients. METHODS: Two dimensions of clinical insight previously identified by a factor analysis of 4 insight assessments were used: Awareness of Illness and Need for Treatment (AINT) and Awareness of Symptoms and Consequences (ASC). T1-weighted structural images were acquired on a 3 T MRI scanner for 110 schizophrenia patients and 69 healthy controls. MR images were processed using CIVET (version 2.0) and MAGeT and quality controlled pre and post-processing. Whole-brain and region-of-interest, vertex-wise linear models were applied between cortical thickness, and levels of AINT and ASC. Partial correlations were conducted between volumes of the amygdala, thalamus, striatum, and hippocampus and insight levels. RESULTS: No significant associations between both insight factors and cortical thickness were observed. Moreover, no significant associations emerged between subcortical volumes and both insight factors. CONCLUSIONS: These results do not replicate previous findings obtained with smaller samples using single-item measures of insight into illness, suggesting a limited role of neurobiological factors and a greater role of psychological processes in explaining levels of clinical insight.


Assuntos
Conscientização/fisiologia , Gânglios da Base/patologia , Córtex Cerebral/patologia , Autoavaliação Diagnóstica , Esquizofrenia/patologia , Esquizofrenia/fisiopatologia , Tálamo/patologia , Adolescente , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/patologia , Gânglios da Base/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/patologia , Feminino , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esquizofrenia/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Adulto Jovem
3.
Neuroimage ; 170: 182-198, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28259781

RESUMO

Accurate automated quantification of subcortical structures is a greatly pursued endeavour in neuroimaging. In an effort to establish the validity and reliability of these methods in defining the striatum, globus pallidus, and thalamus, we investigated differences in volumetry between manual delineation and automated segmentations derived by widely used FreeSurfer and FSL packages, and a more recent segmentation method, the MAGeT-Brain algorithm. In a first set of experiments, the basal ganglia and thalamus of thirty subjects (15 first episode psychosis [FEP], 15 controls) were manually defined and compared to the labels generated by the three automated methods. Our results suggest that all methods overestimate volumes compared to the manually derived "gold standard", with the least pronounced differences produced using MAGeT. The least between-method variability was noted for the striatum, whereas marked differences between manual segmentation and MAGeT compared to FreeSurfer and FSL emerged for the globus pallidus and thalamus. Correlations between manual segmentation and automated methods were strongest for MAGeT (range: 0.51 to 0.92; p<0.01, corrected), whereas FreeSurfer and FSL showed moderate to strong Pearson correlations (range 0.44-0.86; p<0.05, corrected), with the exception of FreeSurfer pallidal (r=0.31, p=0.10) and FSL thalamic segmentations (r=0.37, p=0.051). Bland-Altman plots highlighted a tendency for greater volumetric differences between manual labels and automated methods at the lower end of the distribution (i.e. smaller structures), which was most prominent for bilateral thalamus across automated pipelines, and left globus pallidus for FSL. We then went on to examine volume and shape of the basal ganglia structures using automated techniques in 135 FEP patients and 88 controls. The striatum and globus pallidus were significantly larger in FEP patients compared to controls bilaterally, irrespective of the method used. MAGeT-Brain was more sensitive to shape-based group differences, and uncovered widespread surface expansions in the striatum and globus pallidus bilaterally in FEP patients compared to controls, and surface contractions in bilateral thalamus (FDR-corrected). By contrast, after using a recommended cluster-wise thresholding method, FSL only detected differences in the right ventral striatum (FEP>Control) and one cluster of the left thalamus (Control>FEP). These results suggest that different automated pipelines segment subcortical structures with varying degrees of variability compared to manual methods, with particularly pronounced differences found with FreeSurfer and FSL for the globus pallidus and thalamus.


Assuntos
Corpo Estriado/diagnóstico por imagem , Globo Pálido/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/normas , Imageamento por Ressonância Magnética/normas , Neuroimagem/normas , Transtornos Psicóticos/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Adulto , Corpo Estriado/anatomia & histologia , Feminino , Globo Pálido/anatomia & histologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Neuroimagem/métodos , Transtornos Psicóticos/patologia , Reprodutibilidade dos Testes , Tálamo/anatomia & histologia , Adulto Jovem
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