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1.
Hum Brain Mapp ; 38(11): 5343-5355, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28744969

RESUMO

People with autism spectrum disorder (ASD) have poor decision-making and temporal foresight. This may adversely impact on their everyday life, mental health, and productivity. However, the neural substrates underlying poor choice behavior in people with ASD, or its' neurofunctional development from childhood to adulthood, are unknown. Despite evidence of atypical structural brain development in ASD, investigation of functional brain maturation in people with ASD is lacking. This cross-sectional developmental fMRI study investigated the neural substrates underlying performance on a temporal discounting (TD) task in 38 healthy (11-35 years old) male adolescents and adults with ASD and 40 age, sex, and IQ-matched typically developing healthy controls. Most importantly, we assessed group differences in the neurofunctional maturation of TD across childhood and adulthood. Males with ASD had significantly poorer task performance and significantly lower brain activation in typical regions that mediate TD for delayed choices, in predominantly right hemispheric regions of ventrolateral/dorsolateral prefrontal cortices, ventromedial prefrontal cortex, striatolimbic regions, and cerebellum. Importantly, differential activation in ventromedial frontal cortex and cerebellum was associated with abnormal functional brain maturation; controls, in contrast to people with ASD, showed progressively increasing activation with increasing age in these regions; which furthermore was associated with performance measures and clinical ASD measures (stereotyped/restricted interests). Findings provide first cross-sectional evidence that reduced activation of TD mediating brain regions in people with ASD during TD is associated with abnormal functional brain development in these regions between childhood and adulthood, and this is related to poor task performance and clinical measures of ASD. Hum Brain Mapp 38:5343-5355, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Cerebelo/fisiopatologia , Desvalorização pelo Atraso/fisiologia , Córtex Pré-Frontal/fisiopatologia , Adolescente , Adulto , Área Sob a Curva , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/psicologia , Mapeamento Encefálico , Cerebelo/diagnóstico por imagem , Cerebelo/crescimento & desenvolvimento , Criança , Estudos Transversais , Humanos , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/crescimento & desenvolvimento , Tempo de Reação , Adulto Jovem
2.
J Med Genet ; 53(8): 536-47, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27073233

RESUMO

BACKGROUND: The pseudoautosomal short stature homeobox-containing (SHOX) gene encodes a homeodomain transcription factor involved in cell-cycle and growth regulation. SHOX/SHOX enhancers deletions cause short stature and skeletal abnormalities in a female-dominant fashion; duplications appear to be rare. Neurodevelopmental disorders (NDDs), such as autism spectrum disorders (ASDs), are complex disorders with high heritability and skewed sex ratio; several rare (<1% frequency) CNVs have been implicated in risk. METHODS: We analysed data from a discovery series of 90 adult ASD cases, who underwent clinical genetic testing by array-comparative genomic hybridisation (CGH). Twenty-seven individuals harboured CNV abnormalities, including two unrelated females with microduplications affecting SHOX. To determine the prevalence of SHOX duplications and delineate their associated phenotypic spectrum, we subsequently examined array-CGH data from a follow-up sample of 26 574 patients, including 18 857 with NDD (3541 with ASD). RESULTS: We found a significant enrichment of SHOX microduplications in the NDD cases (p=0.00036; OR 2.21) and, particularly, in those with ASD (p=9.18×10(-7); OR 3.63) compared with 12 594 population-based controls. SHOX duplications affecting the upstream or downstream enhancers were enriched only in females with NDD (p=0.0043; OR 2.69/p=0.00020; OR 7.20), but not in males (p=0.404; OR 1.38/p=0.096; OR 2.21). CONCLUSIONS: Microduplications at the SHOX locus are a low penetrance risk factor for ASD/NDD, with increased risk in both sexes. However, a concomitant duplication of SHOX enhancers may be required to trigger a NDD in females. Since specific SHOX isoforms are exclusively expressed in the developing foetal brain, this may reflect the pathogenic effect of altered SHOX protein dosage on neurodevelopment.


Assuntos
Transtorno do Espectro Autista/genética , Variações do Número de Cópias de DNA/genética , Duplicação Gênica/genética , Proteínas de Homeodomínio/genética , Transtornos do Neurodesenvolvimento/genética , Regiões Pseudoautossômicas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Hibridização Genômica Comparativa/métodos , Feminino , Testes Genéticos/métodos , Transtornos do Crescimento/genética , Humanos , Masculino , Pessoa de Meia-Idade , Deleção de Sequência/genética , Proteína de Homoeobox de Baixa Estatura , Fatores de Transcrição/genética , Adulto Jovem
3.
Brain ; 137(Pt 9): 2600-10, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25070512

RESUMO

It has been suggested that the restricted, stereotyped and repetitive behaviours typically found in autism are underpinned by deficits of inhibitory control. The biological basis of this is unknown but may include differences in the modulatory role of neurotransmitters, such as serotonin, which are implicated in the condition. However, this has never been tested directly. We therefore assessed the modifying role of serotonin on inhibitory brain function during a Go/No-Go task in 14 adults with autism and normal intelligence and 14 control subjects that did not differ in gender, age and intelligence. We undertook a double-blind, placebo-controlled, crossover trial of acute tryptophan depletion using functional magnetic resonance imaging. Following sham, adults with autism relative to controls had reduced activation in key inhibitory regions of inferior frontal cortex and thalamus, but increased activation of caudate and cerebellum. However, brain activation was modulated in opposite ways by depletion in each group. Within autistic individuals depletion upregulated fronto-thalamic activations and downregulated striato-cerebellar activations toward control sham levels, completely 'normalizing' the fronto-cerebellar dysfunctions. The opposite pattern occurred in controls. Moreover, the severity of autism was related to the degree of differential modulation by depletion within frontal, striatal and thalamic regions. Our findings demonstrate that individuals with autism have abnormal inhibitory networks, and that serotonin has a differential, opposite, effect on them in adults with and without autism. Together these factors may partially explain the severity of autistic behaviours and/or provide a novel (tractable) treatment target.


Assuntos
Transtorno Autístico/metabolismo , Encéfalo/metabolismo , Imageamento por Ressonância Magnética , Tempo de Reação/fisiologia , Serotonina/metabolismo , Triptofano/metabolismo , Adolescente , Adulto , Transtorno Autístico/diagnóstico , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Inibição Neural/fisiologia , Estimulação Luminosa/métodos , Adulto Jovem
4.
J Psychopharmacol ; 36(6): 723-731, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35491679

RESUMO

BACKGROUND: Alterations in the serotonergic control of brain pathways responsible for facial emotion processing in people with autism spectrum disorder (ASD) may be a target for intervention. However, the molecular underpinnings of autistic-neurotypical serotonergic differences are challenging to access in vivo. Receptor-Enriched Analysis of functional Connectivity by Targets (REACT) has helped define molecular-enriched functional magnetic resonance imaging (fMRI) brain networks based on a priori information about the spatial distribution of neurochemical systems from available PET templates. METHODS: We used REACT to estimate the dominant fMRI signal related to the serotonin (5-HT) transporter (SERT) distribution during processing of aversive facial emotion in adults with and without ASD. We first predicted a group difference in baseline (placebo) functioning of this system. We next used a single 20 mg oral dose of citalopram, a serotonin reuptake inhibitor, to test the hypothesis that network activity in people with and without ASD would respond differently to inhibition of SERT. To confirm the specificity of our findings, we also repeated the analysis with 5-HT1A, 5-HT1B, 5-HT2A and 5-HT4 receptor maps. RESULTS: Using REACT with the SERT map, we found a baseline group difference in the SERT-enriched response to faces in the ventromedial prefrontal cortex. A single oral dose of citalopram 'shifted' the response in the ASD group towards the neurotypical baseline but did not alter response in the control group. Similar differences in SERT-enriched response were observed after controlling for other 5-HT maps. CONCLUSIONS: Our findings suggest that the SERT-enriched functional network is dynamically different in ASD during processing of socially relevant stimuli. Whether this acute neurobiological response to citalopram in ASD translates to a clinical target will be an important next step.


Assuntos
Transtorno do Espectro Autista , Proteínas da Membrana Plasmática de Transporte de Serotonina , Adulto , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/tratamento farmacológico , Encéfalo/metabolismo , Citalopram/farmacologia , Citalopram/uso terapêutico , Estudos Cross-Over , Humanos , Imageamento por Ressonância Magnética , Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo
5.
Autism ; 26(8): 2098-2107, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35261275

RESUMO

LAY ABSTRACT: There has been growing interest in offending and contact with the criminal justice system (CJS) by people with autism spectrum disorder (ASD). However, it is not clear whether people with ASD offend more than those without ASD. Studies have started to look at whether there are particular offences people with ASD are more likely to commit and whether there are any factors that can affect whether someone comes into contact with the CJS as a potential suspect. This study looked at the patients who attended an ASD diagnostic service over a 17-year period to see the rate of contact with the CJS of those who were diagnosed with ASD and whether there were any particular factors that might increase the risk of CJS contact. Nearly a quarter of the ASD group had some contact with the CJS as a potential suspect. Factors that seemed to increase whether someone with ASD was more likely to have contact with the CJS were being male, being diagnosed with ADHD, and being diagnosed with psychosis. This study is one of the largest studies to investigate the rate of CJS contact as a potential suspect in a sample of adults with ASD in an attempt to give a clearer picture of what might influence someone with ASD to engage in offending behaviour in order to try to see what mental health services can offer to reduce the likelihood of someone with ASD coming into contact with the CJS, for example, treatment for another condition or support.


Assuntos
Transtorno do Espectro Autista , Adulto , Humanos , Masculino , Feminino , Transtorno do Espectro Autista/epidemiologia , Direito Penal , Prevalência , Caracteres Sexuais , Fatores de Risco
6.
J Neurosci ; 30(32): 10612-23, 2010 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-20702694

RESUMO

Autism spectrum disorder (ASD) is a neurodevelopmental condition with multiple causes, comorbid conditions, and a wide range in the type and severity of symptoms expressed by different individuals. This makes the neuroanatomy of autism inherently difficult to describe. Here, we demonstrate how a multiparameter classification approach can be used to characterize the complex and subtle structural pattern of gray matter anatomy implicated in adults with ASD, and to reveal spatially distributed patterns of discriminating regions for a variety of parameters describing brain anatomy. A set of five morphological parameters including volumetric and geometric features at each spatial location on the cortical surface was used to discriminate between people with ASD and controls using a support vector machine (SVM) analytic approach, and to find a spatially distributed pattern of regions with maximal classification weights. On the basis of these patterns, SVM was able to identify individuals with ASD at a sensitivity and specificity of up to 90% and 80%, respectively. However, the ability of individual cortical features to discriminate between groups was highly variable, and the discriminating patterns of regions varied across parameters. The classification was specific to ASD rather than neurodevelopmental conditions in general (e.g., attention deficit hyperactivity disorder). Our results confirm the hypothesis that the neuroanatomy of autism is truly multidimensional, and affects multiple and most likely independent cortical features. The spatial patterns detected using SVM may help further exploration of the specific genetic and neuropathological underpinnings of ASD, and provide new insights into the most likely multifactorial etiology of the condition.


Assuntos
Transtorno Autístico/diagnóstico , Transtorno Autístico/fisiopatologia , Encéfalo/patologia , Transtornos Globais do Desenvolvimento Infantil/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Idoso , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Mapeamento Encefálico/métodos , Estudos de Casos e Controles , Criança , Transtornos Globais do Desenvolvimento Infantil/classificação , Transtornos Globais do Desenvolvimento Infantil/complicações , Humanos , Processamento de Imagem Assistida por Computador/métodos , Testes de Inteligência , Masculino , Pessoa de Meia-Idade , Curva ROC , Índice de Gravidade de Doença , Estatística como Assunto , Adulto Jovem
7.
Neuroimage ; 54(1): 16-24, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-20708694

RESUMO

Fragile X Syndrome (FraX) is caused by the expansion of a single trinucleotide gene sequence (CGG) on the X chromosome, and is a leading cause of learning disability (mental retardation) worldwide. Relatively few studies, however, have examined the neuroanatomical abnormalities associated with FraX. Of those that are available many included mixed gender populations, combined FraX children and adults into one sample, and employed manual tracing techniques which measures bulk volume of particular regions. Hence, there is relatively little information on differences in grey and white matter content across whole brain. We employed magnetic resonance imaging to investigate brain anatomy in 17 adult males with FraX and 18 healthy controls that did not differ significantly in age. Data were analysed using stereology and VBM to compare (respectively) regional brain bulk volume, and localised grey/white matter content. Using stereology we found that FraX males had a significant increase in bulk volume bilaterally of the caudate nucleus and parietal lobes and of the right brainstem, but a significant decrease in volume of the left frontal lobe. Our complimentary VBM analysis revealed an increased volume of grey matter in fronto-striatal regions (including bilaterally in the caudate nucleus), and increased white matter in regions extending from the brainstem to the parahippocampal gyrus, and from the left cingulate cortex extending into the corpus callosum. People with FraX have regionally specific differences in brain anatomy from healthy controls with enlargement of the caudate nuclei that persists into adulthood.


Assuntos
Encéfalo/anatomia & histologia , Síndrome do Cromossomo X Frágil/patologia , Adulto , Encéfalo/patologia , Mapeamento Encefálico/métodos , Tronco Encefálico/anatomia & histologia , Tronco Encefálico/patologia , Núcleo Caudado/anatomia & histologia , Núcleo Caudado/patologia , Corpo Caloso/anatomia & histologia , Corpo Caloso/patologia , Expansão das Repetições de DNA/genética , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Síndrome do Cromossomo X Frágil/psicologia , Lateralidade Funcional , Genótipo , Humanos , Testes de Inteligência , Imageamento por Ressonância Magnética/métodos , Masculino , Tamanho do Órgão , Reação em Cadeia da Polimerase , Valores de Referência , Repetições de Trinucleotídeos/genética , Adulto Jovem
8.
Cereb Cortex ; 20(6): 1332-40, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19819933

RESUMO

There is increasing evidence that children with autism spectrum disorder (ASD) have age-related differences from controls in cortical volume (CV). It is less clear, however, if these persist in adulthood and whether these reflect alterations in cortical thickness (CT) or cortical surface area (SA). Hence, we used magnetic resonance imaging to investigate the relationship between age and CV, CT, and SA in 127 males aged 10 through 60 years (76 with ASD and 51 healthy controls). "Regional" analyses (using cortical parcellation) identified significant age-by-group interactions in both CV and CT (but not SA) in the temporal lobes and within these the fusiform and middle temporal gyri. Spatially nonbiased "vertex-based" analysis replicated these results and identified additional "age-by-group" interactions for CT within superior temporal, inferior and medial frontal, and inferior parietal cortices. Here, CV and CT were 1) significantly negatively correlated with age in controls, but not in ASD, and 2) smaller in ASD than controls in childhood but vice versa in adulthood. Our findings suggest that CV dysmaturation in ASD extends beyond childhood, affects brain regions crucial to social cognition and language, and is driven by CT dysmaturation. This may reflect primary abnormalities in cortical plasticity and/or be secondary to disturbed interactions between individuals with ASD and their environment.


Assuntos
Córtex Cerebral/anormalidades , Córtex Cerebral/patologia , Transtornos Globais do Desenvolvimento Infantil/patologia , Malformações do Sistema Nervoso/patologia , Adolescente , Adulto , Envelhecimento/patologia , Atrofia , Mapeamento Encefálico , Córtex Cerebral/crescimento & desenvolvimento , Criança , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Lobo Frontal/anormalidades , Lobo Frontal/crescimento & desenvolvimento , Lobo Frontal/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Malformações do Sistema Nervoso/fisiopatologia , Lobo Temporal/anormalidades , Lobo Temporal/crescimento & desenvolvimento , Lobo Temporal/patologia , Adulto Jovem
9.
Mol Autism ; 12(1): 14, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608048

RESUMO

BACKGROUND: Autism spectrum disorder (ASD) is associated with deficits in executive functioning (EF), and these have been suggested to contribute to core as well as co-occurring psychiatric symptoms. The biological basis of these deficits is unknown but may include the serotonergic system, which is involved both in regulating EF in neurotypical populations and in the pathophysiology of ASD. We previously demonstrated that reducing serotonin by acute tryptophan depletion (ATD) shifts differences in brain function during performance of EF tasks towards control levels. However, ATD cannot be easily used in the clinic, and we therefore need to adopt alternative approaches to challenge the serotonin system. Hence, we investigated the role of the serotonergic modulator tianeptine on EF networks in ASD. METHOD: We conducted a pharmacological magnetic resonance imaging study, using a randomized double-blind crossover design, to compare the effect of an acute dosage of 12.5 mg tianeptine and placebo on brain activation during two EF tasks (of response inhibition and sustained attention) in 38 adult males: 19 with ASD and 19 matched controls. RESULTS: Under placebo, compared to controls, individuals with ASD had atypical brain activation in response inhibition regions including the inferior frontal cortex, premotor regions and cerebellum. During sustained attention, individuals with ASD had decreased brain activation in the right middle temporal cortex, right cuneus and left precuneus. Most of the case-control differences in brain function observed under placebo conditions were abolished by tianeptine administration. Also, within ASD individuals, brain functional differences were shifted significantly towards control levels during response inhibition in the inferior frontal and premotor cortices. LIMITATIONS: We conducted a pilot study using a single dose of tianeptine, and therefore, we cannot comment on long-term outcome. CONCLUSIONS: Our findings provide the first evidence that tianeptine can shift atypical brain activation during EF in adults with ASD towards control levels. Future studies should investigate whether this shift in the biology of ASD is maintained after prolonged treatment with tianeptine and whether it improves clinical symptoms.


Assuntos
Antidepressivos Tricíclicos/uso terapêutico , Transtorno Autístico/tratamento farmacológico , Encéfalo/diagnóstico por imagem , Função Executiva/efeitos dos fármacos , Tiazepinas/uso terapêutico , Adulto , Atenção/efeitos dos fármacos , Transtorno Autístico/diagnóstico por imagem , Transtorno Autístico/fisiopatologia , Transtorno Autístico/psicologia , Encéfalo/fisiopatologia , Estudos Cross-Over , Método Duplo-Cego , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Adulto Jovem
10.
Neuroimage ; 49(4): 2915-23, 2010 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19948228

RESUMO

Turner syndrome (TS) is a model for X chromosome influences on neurodevelopment because it is most commonly caused by absence of one X chromosome and associated with altered brain structure and function. However, all prior in vivo magnetic resonance imaging studies of the brain in TS have either used manual approaches or voxel-based morphometry (VBM) to measure cortical volume (CV). These methods, unlike surface-based morphometry (SBM), cannot measure the two neurobiologically distinct determinants of CV- cortical thickness (CT) and surface area (SA) - which have differing genetic determinants and may be independently altered. Therefore, in 24 adults with X monosomy and 19 healthy female controls, we used SBM to compare (i) lobar CV, CT and SA; (ii) an index of hemispheric gyrification; (iii) CT throughout the cortical sheet; and (iv) CT correlation between cortical regions. Compared to controls, females with TS had (i) significantly increased CT and decreased SA in parietal and occipital lobes (resulting in no significant difference in lobar CV); (ii) reduced hemispheric gyrification bilaterally; (iii) foci of significantly increased CT involving inferior temporal, lateral occipital, intraparietal sulcus (IPS), cingulate and orbitofrontal cortices; and (iv) significantly reduced CT correlation between the left IPS and cortical regions including supramarginal and lateral occipital gyri. Our findings suggest that females with TS have complex, sometimes "opposing", abnormalities in SA/gyrification (decreased) and CT (increased), which can result in no overall detectable differences in CV. Thus, haploinsufficiency of X chromosome genes, may differentially impact the distinct mechanisms shaping SA (e.g. cortical folding) and CT (e.g. dendritic arborization/pruning). CT disruptions are maximal within and between cortical regions previously implicated in the TS cognitive phenotype.


Assuntos
Encéfalo/patologia , Córtex Cerebral/patologia , Monossomia , Síndrome de Turner/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino
11.
Psychiatry Res ; 184(2): 77-85, 2010 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-20952166

RESUMO

People with autistic spectrum disorders (ASD, including Asperger syndrome) may have developmental abnormalities in the amygdala-hippocampal complex (AHC). However, in vivo, age-related comparisons of both volume and neuronal integrity of the AHC have not yet been carried out in people with Asperger syndrome (AS) versus controls. We compared structure and metabolic activity of the right AHC of 22 individuals with AS and 22 healthy controls aged 10-50 years and examined the effects of age between groups. We used structural magnetic resonance imaging (sMRI) to measure the volume of the AHC, and magnetic resonance spectroscopy ((1)H-MRS) to measure concentrations of N-acetyl aspartate (NAA), creatine+phosphocreatine (Cr+PCr), myo-inositol (mI) and choline (Cho). The bulk volume of the amygdala and the hippocampus did not differ significantly between groups, but there was a significant difference in the effect of age on the hippocampus in controls. Compared with controls, young (but not older) people with AS had a significantly higher AHC concentration of NAA and a significantly higher NAA/Cr ratio. People with AS, but not controls, had a significant age-related reduction in NAA and the NAA/Cr ratio. Also, in people with AS, but not controls, there was a significant relationship between concentrations of choline and age so that choline concentrations reduced with age. We therefore suggest that people with AS have significant differences in neuronal and lipid membrane integrity and maturation of the AHC.


Assuntos
Envelhecimento/metabolismo , Tonsila do Cerebelo/metabolismo , Síndrome de Asperger/metabolismo , Hipocampo/metabolismo , Adolescente , Adulto , Fatores Etários , Envelhecimento/patologia , Tonsila do Cerebelo/química , Tonsila do Cerebelo/patologia , Ácido Aspártico/análogos & derivados , Ácido Aspártico/análise , Ácido Aspártico/metabolismo , Síndrome de Asperger/patologia , Mapeamento Encefálico , Criança , Colina/análise , Colina/metabolismo , Creatina/análise , Creatina/metabolismo , Feminino , Hipocampo/química , Hipocampo/patologia , Humanos , Processamento de Imagem Assistida por Computador , Inositol/análise , Inositol/metabolismo , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Fosfocreatina/análise , Fosfocreatina/metabolismo
12.
Neuroimage ; 47(2): 427-34, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19446642

RESUMO

It has been suggested that people with autistic spectrum disorder (ASD) have altered development (and connectivity) of limbic circuits. However, direct evidence of anatomical differences specific to white matter pathways underlying social behaviour and emotions in ASD is lacking. We used Diffusion Tensor Imaging Tractography to compare, in vivo, the microstructural integrity and age-related differences in the extended limbic pathways between subjects with Asperger syndrome and healthy controls. Twenty-four males with Asperger syndrome (mean age 23+/-12 years, age range: 9-54 years) and 42 age-matched male controls (mean age 25+/-10 years, age range: 9-54 years) were studied. We quantified tract-specific diffusivity measurements as indirect indexes of microstructural integrity (e.g. fractional anisotropy, FA; mean diffusivity, MD) and tract volume (e.g. number of streamlines) of the main limbic tracts. The dissected limbic pathways included the inferior longitudinal fasciculus, inferior frontal occipital fasciculus, uncinate, cingulum and fornix. There were no significant between-group differences in FA and MD. However, compared to healthy controls, individuals with Asperger syndrome had a significantly higher number of streamlines in the right (p=.003) and left (p=.03) cingulum, and in the right (p=.03) and left (p=.04) inferior longitudinal fasciculus. In contrast, people with Asperger syndrome had a significantly lower number of streamlines in the right uncinate (p=.02). Within each group there were significant age-related differences in MD and number of streamlines, but not FA. However, the only significant age-related between-group difference was in mean diffusivity of the left uncinate fasciculus (Z(obs)=2.05) (p=.02). Our preliminary findings suggest that people with Asperger syndrome have significant differences in the anatomy, and maturation, of some (but not all) limbic tracts.


Assuntos
Síndrome de Asperger/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Sistema Límbico/patologia , Fibras Nervosas Mielinizadas/ultraestrutura , Vias Neurais/patologia , Adolescente , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Adulto Jovem
13.
Am J Med Genet B Neuropsychiatr Genet ; 150B(1): 74-85, 2009 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-18454450

RESUMO

The cognitive deficits present in individuals with sex chromosome aneuploidies suggest that hemispheric differentiation of function is determined by an X-Y homologous gene [Crow (1993); Lancet 342:594-598]. In particular, females with Turner's syndrome (TS) who have only one X-chromosome exhibit deficits of spatial ability whereas males with Klinefelter's syndrome (KS) who possess a supernumerary X-chromosome are delayed in acquiring words. Since spatial and verbal abilities are generally associated with right and left hemispheric function, such deficits may relate to anomalies of cerebral asymmetry. We therefore applied a novel image analysis technique to investigate the relationship between sex chromosome dosage and structural brain asymmetry. Specifically, we tested Crow's prediction that the magnitude of the brain torque (i.e., a combination of rightward frontal and leftward occipital asymmetry) would, as a function of sex chromosome dosage, be respectively decreased in TS women and increased in KS men, relative to genotypically normal controls. We found that brain torque was not significantly different in TS women and KS men, in comparison to controls. However, TS women exhibited significantly increased leftward brain asymmetry, restricted to the posterior of the brain and focused on the superior temporal and parietal-occipital association cortex, while KS men showed a trend for decreased brain asymmetry throughout the frontal lobes. The findings suggest that the number of sex chromosomes influences the development of brain asymmetry not simply to modify the torque but in a complex pattern along the antero-posterior axis.


Assuntos
Aneuploidia , Encéfalo/anormalidades , Cromossomos Sexuais , Feminino , Humanos , Síndrome de Klinefelter/genética , Masculino , Síndrome de Turner/genética
14.
Transl Psychiatry ; 9(1): 286, 2019 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-31712584

RESUMO

Adults with autism spectrum disorder (ASD) are frequently prescribed selective serotonin reuptake inhibitors (SSRIs). However, there is limited evidence to support this practice. Therefore, it is crucial to understand the impact of SSRIs on brain function abnormalities in ASD. It has been suggested that some core symptoms in ASD are underpinned by deficits in executive functioning (EF). Hence, we investigated the role of the SSRI citalopram on EF networks in 19 right-handed adult males with ASD and 19 controls who did not differ in gender, age, IQ or handedness. We performed pharmacological functional magnetic resonance imaging to compare brain activity during two EF tasks (of response inhibition and sustained attention) after an acute dose of 20 mg citalopram or placebo using a randomised, double-blind, crossover design. Under placebo condition, individuals with ASD had abnormal brain activation in response inhibition regions, including inferior frontal, precentral and postcentral cortices and cerebellum. During sustained attention, individuals with ASD had abnormal brain activation in middle temporal cortex and (pre)cuneus. After citalopram administration, abnormal brain activation in inferior frontal cortex was 'normalised' and most of the other brain functional differences were 'abolished'. Also, within ASD, the degree of responsivity in inferior frontal and postcentral cortices to SSRI challenge was related to plasma serotonin levels. These findings suggest that citalopram can 'normalise' atypical brain activation during EF in ASD. Future trials should investigate whether this shift in the biology of ASD is maintained after prolonged citalopram treatment, and if peripheral measures of serotonin predict treatment response.


Assuntos
Transtorno do Espectro Autista/tratamento farmacológico , Transtorno do Espectro Autista/fisiopatologia , Encéfalo/fisiopatologia , Citalopram/uso terapêutico , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Adulto , Atenção/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Mapeamento Encefálico , Citalopram/administração & dosagem , Estudos Cross-Over , Método Duplo-Cego , Função Executiva/efeitos dos fármacos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Inibidores Seletivos de Recaptação de Serotonina/administração & dosagem , Escala Visual Analógica , Adulto Jovem
15.
Biol Psychiatry ; 62(3): 207-17, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17400195

RESUMO

BACKGROUND: People with Asperger syndrome (AS) have life-long deficits in social behavior. The biological basis of this is unknown, but most likely includes impaired processing of facial emotion. Human social communication involves processing different facial emotions, and at different intensities. However nobody has examined brain function in people with AS when implicitly (unconsciously) processing four primary emotions at varying emotional intensities. METHODS: We used event-related functional magnetic resonance imaging (MRI) to examine neural responses when people with AS and controls implicitly processed neutral expressions, and mild (25%) and intense (100%) expressions of fear, disgust, happiness, and sadness. We included 18 right-handed adults; 9 with AS and 9 healthy controls who did not differ significantly in IQ. RESULTS: Both groups significantly activated 'face perception' areas when viewing neutral faces, including fusiform and extrastriate cortices. Further, both groups had significantly increased activation of fusiform and other extrastriate regions to increasing intensities of fear and happiness. However, people with AS generally showed fusiform and extrastriate hyporesponsiveness compared to controls across emotion types and intensities. CONCLUSIONS: Fusiform and extrastriate cortices are activated by facial expressions of four primary emotions in people with AS, but generally to a lesser degree than controls. This may partly explain the social impairments of people with AS.


Assuntos
Síndrome de Asperger/psicologia , Mapeamento Encefálico , Discriminação Psicológica/fisiologia , Potenciais Evocados/fisiologia , Expressão Facial , Percepção Social , Adulto , Análise de Variância , Síndrome de Asperger/fisiopatologia , Estudos de Casos e Controles , Emoções , Humanos , Imageamento por Ressonância Magnética , Masculino , Reconhecimento Visual de Modelos/fisiologia , Valores de Referência , Lobo Temporal/fisiologia , Lobo Temporal/fisiopatologia
16.
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
17.
Schizophr Res ; 171(1-3): 215-24, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26827129

RESUMO

The primary aim of this systematic review and meta-analysis was to assess the proportion of patients with Treatment Resistant Schizophrenia (TRS) that respond to ECT augmentation of clozapine (C+ECT). We searched major electronic databases from 1980 to July 2015. We conducted a random effects meta-analysis reporting the proportion of responders to C+ECT in RCTs and open-label trials. Five clinical trials met our eligibility criteria, allowing us to pool data from 71 people with TRS who underwent C+ ECT across 4 open label trials (n=32) and 1 RCT (n=39). The overall pooled proportion of response to C+ECT was 54%, (95% CI: 21.8-83.6%) with some heterogeneity evident (I(2)=69%). With data from retrospective chart reviews, case series and case reports, 192 people treated with C+ECT were included. All studies together demonstrated an overall response to C+ECT of 66% (95% CI: 57.5-74.3%) (83 out of 126 patients responded to C+ECT). The mean number of ECT treatments used to augment clozapine was 11.3. 32% of cases (20 out of 62 patients) with follow up data (range of follow up: 3-468weeks) relapsed following cessation of ECT. Adverse events were reported in 14% of identified cases (24 out of 166 patients). There is a paucity of controlled studies in the literature, with only one single blinded randomised controlled study located, and the predominance of open label trials used in the meta-analysis is a limitation. The data suggests that ECT may be an effective and safe clozapine augmentation strategy in TRS. A higher number of ECT treatments may be required than is standard for other clinical indications. Further research is needed before ECT can be included in standard TRS treatment algorithms.


Assuntos
Antipsicóticos/uso terapêutico , Clozapina/uso terapêutico , Eletroconvulsoterapia/métodos , Esquizofrenia/terapia , Humanos
18.
Neuropsychiatr Dis Treat ; 12: 1669-86, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27462160

RESUMO

Autism spectrum disorder (ASD) is a common neurodevelopmental disorder characterized by pervasive difficulties since early childhood across reciprocal social communication and restricted, repetitive interests and behaviors. Although early ASD research focused primarily on children, there is increasing recognition that ASD is a lifelong neurodevelopmental disorder. However, although health and education services for children with ASD are relatively well established, service provision for adults with ASD is in its infancy. There is a lack of health services research for adults with ASD, including identification of comorbid health difficulties, rigorous treatment trials (pharmacological and psychological), development of new pharmacotherapies, investigation of transition and aging across the lifespan, and consideration of sex differences and the views of people with ASD. This article reviews available evidence regarding the etiology, legislation, diagnosis, management, and service provision for adults with ASD and considers what is needed to support adults with ASD as they age. We conclude that health services research for adults with ASD is urgently warranted. In particular, research is required to better understand the needs of adults with ASD, including health, aging, service development, transition, treatment options across the lifespan, sex, and the views of people with ASD. Additionally, the outcomes of recent international legislative efforts to raise awareness of ASD and service provision for adults with ASD are to be determined. Future research is required to identify high-quality, evidence-based, and cost-effective models of care. Furthermore, future health services research is also required at the beginning and end of adulthood, including improved transition from youth to adult health care and increased understanding of aging and health in older adults with ASD.

19.
Autism Res ; 9(4): 429-435, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26290215

RESUMO

Increased oxidative stress has been postulated to contribute to the pathogenesis of autism spectrum disorder (ASD). However, reports of alterations in oxidation markers including glutathione (GSH), the major endogenous antioxidant, are indirect, coming from blood plasma level measurements and postmortem studies. Therefore we used in-vivo 3 Tesla proton magnetic resonance spectroscopy ([1H]MRS) to directly measure GSH concentrations in the basal ganglia (BG) and the dorsomedial prefrontal cortex of 21 normally intelligent adult males with ASD and 29 controls who did not differ in age or IQ. There was no difference in brain GSH between patients and controls in either brain area; neither did GSH levels correlate with measures of clinical severity in patients. Thus [1H]MRS measures of cortical and subcortical GSH are not a biomarker for ASD in intellectually able adult men.


Assuntos
Transtorno do Espectro Autista/metabolismo , Gânglios da Base/metabolismo , Glutationa/metabolismo , Córtex Pré-Frontal/metabolismo , Adolescente , Adulto , Transtorno do Espectro Autista/diagnóstico por imagem , Gânglios da Base/diagnóstico por imagem , Mapeamento Encefálico/métodos , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/diagnóstico por imagem , Prótons , Adulto Jovem
20.
Autism ; 20(5): 623-7, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26471427

RESUMO

Growing awareness of autism spectrum disorders has increased the demand for diagnostic services in adulthood. High rates of mental health problems have been reported in young people and adults with autism spectrum disorder. However, sampling and methodological issues mean prevalence estimates and conclusions about specificity in psychiatric co-morbidity in autism spectrum disorder remain unclear. A retrospective case review of 859 adults referred for assessment of autism spectrum disorder compares International Classification of Diseases, Tenth Revision diagnoses in those that met criteria for autism spectrum disorder (n = 474) with those that did not (n = 385). Rates of psychiatric diagnosis (>57%) were equivalent across both groups and exceeded general population rates for a number of conditions. The prevalence of anxiety disorders, particularly obsessive compulsive disorder, was significantly higher in adults with autism spectrum disorder than adults without autism spectrum disorder. Limitations of this observational clinic study, which may impact generalisability of the findings, include the lack of standardised structured psychiatric diagnostic assessments by assessors blind to autism spectrum disorder diagnosis and inter-rater reliability. The implications of this study highlight the need for careful consideration of mental health needs in all adults referred for autism spectrum disorder diagnosis.


Assuntos
Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/psicologia , Adulto , Transtorno do Espectro Autista/diagnóstico , Comorbidade , Feminino , Humanos , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/epidemiologia , Transtornos Mentais/psicologia , Prevalência , Reprodutibilidade dos Testes , Estudos Retrospectivos , Reino Unido/epidemiologia
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