Pubmed du 06/02/14

Pubmed du jour

2014-02-06 12:03:50

1. Bejerot S, Eriksson JM. {{Sexuality and gender role in autism spectrum disorder: a case control study}}. {PloS one}. 2014;9(1):e87961.

The ‘extreme male brain theory of autism’ describes an extreme male pattern of cognitive traits defined as strong systemising abilities paired with empathising weaknesses in autism spectrum disorder. However, beyond these cognitive traits, clinical observations have suggested an ambiguous gender-typed pattern regarding several sexually dimorphic traits. The aim of the present study was to investigate if patterns of non-cognitive sexually dimorphic traits differed between the autism spectrum disorder and control groups. Fifty adults with autism spectrum disorder and intelligence within the normal range, and 53 neurotypical controls responded to questions on gender role, self-perceived gender typicality and gender identity, as well as sexuality. Measures used were a Swedish modification of the Bem Sex Role Inventory and questions on sexuality and gender designed for the purpose of this study. Our results showed that one common gender role emerged in the autism spectrum disorder group. Masculinity (e.g. assertiveness, leadership and competitiveness) was weaker in the autism spectrum disorder group than in the controls, across men and women. Self-perceived gender typicality did not differ between the groups but tomboyism and bisexuality were overrepresented amongst women with autism spectrum disorder. Lower libido was reported amongst both male and female participants with autism spectrum disorder compared with controls. We conclude that the extreme male patterns of cognitive functions in the autistic brain do not seem to extend to gender role and sexuality. A gender-atypical pattern for these types of characteristics is suggested in autism spectrum disorder.

Lien vers le texte intégral (Open Access ou abonnement)

2. Clipperton-Allen AE, Page DT. {{Pten haploinsufficient mice show broad brain overgrowth but selective impairments in autism-relevant behavioral tests}}. {Human molecular genetics}. 2014 Feb 4.

Accelerated head and brain growth (macrocephaly) during development is a replicated biological finding in a subset of individuals with autism spectrum disorder (ASD). However, the relationship between brain overgrowth and the behavioral and cognitive symptoms of ASD is poorly understood. The PI3K-Akt-mTOR pathway regulates cellular growth; several genes encoding negative regulators of this pathway are ASD risk factors, including PTEN. Mutations in PTEN have been reported in individuals with ASD and macrocephaly. We report that brain overgrowth is widespread in Pten germline haploinsufficient (Pten+/-) mice, reflecting Pten mRNA expression in the developing brain. We then ask if broad brain overgrowth translates into general or specific effects on the development of behavior and cognition by testing Pten+/- mice using assays relevant to ASD and comorbidities. Deficits in social behavior were observed in both sexes. Males also showed abnormalities related to repetitive behavior and mood/anxiety. Females exhibited circadian activity and emotional learning phenotypes. Widespread brain overgrowth together with selective behavioral impairments in Pten+/- mice raises the possibility that most brain areas and constituent cell types adapt to an altered trajectory of growth with minimal impact on the behaviors tested in our battery; however, select areas/cell types relevant to social behavior are more vulnerable or less adaptable, thus resulting in social deficits. Probing dopaminergic neurons as a candidate vulnerable cell type, we found social behavioral impairments in mice with Pten conditionally inactivated in dopaminergic neurons that are consistent with the possibility that desynchronized growth in key cell types may contribute to ASD endophenotypes.

Lien vers le texte intégral (Open Access ou abonnement)

3. Devanna P, Vernes SC. {{A direct molecular link between the autism candidate gene RORa and the schizophrenia candidate MIR137}}. {Scientific reports}. 2014;4:3994.

Retinoic acid-related orphan receptor alpha gene (RORa) and the microRNA MIR137 have both recently been identified as novel candidate genes for neuropsychiatric disorders. RORa encodes a ligand-dependent orphan nuclear receptor that acts as a transcriptional regulator and miR-137 is a brain enriched small non-coding RNA that interacts with gene transcripts to control protein levels. Given the mounting evidence for RORa in autism spectrum disorders (ASD) and MIR137 in schizophrenia and ASD, we investigated if there was a functional biological relationship between these two genes. Herein, we demonstrate that miR-137 targets the 3’UTR of RORa in a site specific manner. We also provide further support for MIR137 as an autism candidate by showing that a large number of previously implicated autism genes are also putatively targeted by miR-137. This work supports the role of MIR137 as an ASD candidate and demonstrates a direct biological link between these previously unrelated autism candidate genes.

Lien vers le texte intégral (Open Access ou abonnement)

4. Farmer C, Butter E, Mazurek MO, Cowan C, Lainhart J, Cook EH, Dewitt MB, Aman M. {{Aggression in children with autism spectrum disorders and a clinic-referred comparison group}}. {Autism}. 2014 Feb 4.

A gap exists in the literature regarding aggression in autism spectrum disorders and how this behavior compares to other groups. In this multisite study, the Children’s Scale for Hostility and Aggression: Reactive/Proactive and the Aggression subscale of the Child Behavior Checklist were rated for 414 children with autism spectrum disorder (autistic disorder, 69%; pervasive developmental disorder not otherwise specified, 24%; Asperger’s disorder, 7%) and 243 clinic-referred children without autism spectrum disorder, aged 1-21 years (mean age about 7 years). Participants were not selected for aggressive behavior. Relative to the comparison group, children with autism spectrum disorder were reported to have less aggression and were more likely to be rated as reactive rather than proactive. Among all subjects, sex was not associated with aggression; higher IQ/adaptive behavior and older age were associated with more sophisticated types of aggression, while lower scores on IQ, adaptive behavior, and communication measures were associated with more physical aggression. The interaction between demographic variables and diagnosis was significant only for age: younger but not older children with autism spectrum disorder showed less aggression than clinic-referred controls.

Lien vers le texte intégral (Open Access ou abonnement)

5. Joosten AV, Safe AP. {{Management strategies of mothers of school-age children with autism: Implications for practice}}. {Australian occupational therapy journal}. 2014 Feb 6.

BACKGROUND/AIM: Mothering children with autism results in mothers spending more time on daily tasks as well as managing the disorder. The need for mothers to self-manage often increases when the child is school aged. Mothers develop strategies, and occupational therapists and other health professional rely on or expect mothers to be involved in meeting the extra needs of their children with autism and other family members. Little is known about the strategies adopted by the mothers. The aim of this study was to explore the strategies mothers used to manage their roles and emotions, and their child’s behaviours. METHOD: In-depth individual interviews were conducted with seven mothers and data were analysed in this qualitative study using phenomenological analysis. RESULTS: Findings revealed that the mothers had adopted strategies to manage their roles, their emotions and their child’s behaviour. However, the strategies were often shaped by the expectations of others or circumstances beyond their control and at times added further to their stress. CONCLUSIONS: Mothers of children with autism developed strategies to self-manage their lives and their child’s disorder. However, even when these strategies were effective, they sometimes placed further stress on the mothers. The mothers provided insights to how they coped but need help to consider the support they require and therapists need to consider the pressures of expecting mothers to self-manage their child’s disorder, their own lives and their family. Family-centred practice emphasising collaboration with mothers needs to be maintained with school-aged children.

Lien vers le texte intégral (Open Access ou abonnement)

6. Kawada T. {{Risk assessment for autism spectrum disorders by representative database}}. {Paediatric and perinatal epidemiology}. 2014 Mar;28(2):177.

Lien vers le texte intégral (Open Access ou abonnement)

7. Kuhlthau KA, Warfield ME, Hurson J, Delahaye J, Crossman MK. {{Pediatric provider’s perspectives on the transition to adult health care for youth with autism spectrum disorder: Current strategies and promising new directions}}. {Autism}. 2014 Feb 4.

Few youth with autism spectrum disorder (ASD) nationally report receiving services to help them transition from the pediatric health care system to the adult health care system. For example, only one-fifth (21.1%) of youth with ASD receive any transition planning services. To better understand why the transition from pediatric to adult health care is so difficult, we interviewed pediatric health care providers with extensive experience serving youth with ASD. We gathered information about the strategies and interventions they use to transition their patients with ASD to an adult provider. Five interventions or strategies are currently being used. These include providing families with written medical summaries to give to adult providers, compiling lists of available adult providers or community resources, coordinating care and communication between individual pediatric and adult providers, making transition-specific appointments, and using checklists to track transition progress. Other interventions or strategies were identified as needed but not currently in practice, and these focused on education and training. For example, informational workshops were suggested to train families and youth about transition. Training adult providers and medical students was also seen as important. Several respondents additionally identified the need for a transition center where all services could be coordinated in one place. With large numbers of youth with ASD becoming young adults, it seems that pediatric practices might want to consider some of the activities described here. Some of these activities, such as family educational seminars and written medical summaries, are likely relatively easy for a practice to implement.

Lien vers le texte intégral (Open Access ou abonnement)

8. Maximo JO, Cadena EJ, Kana RK. {{The Implications of Brain Connectivity in the Neuropsychology of Autism}}. {Neuropsychology review}. 2014 Feb 5.

Autism is a neurodevelopmental disorder that has been associated with atypical brain functioning. Functional connectivity MRI (fcMRI) studies examining neural networks in autism have seen an exponential rise over the last decade. Such investigations have led to the characterization of autism as a distributed neural systems disorder. Studies have found widespread cortical underconnectivity, local overconnectivity, and mixed results suggesting disrupted brain connectivity as a potential neural signature of autism. In this review, we summarize the findings of previous fcMRI studies in autism with a detailed examination of their methodology, in order to better understand its potential and to delineate the pitfalls. We also address how a multimodal neuroimaging approach (incorporating different measures of brain connectivity) may help characterize the complex neurobiology of autism at a global level. Finally, we also address the potential of neuroimaging-based markers in assisting neuropsychological assessment of autism. The quest for a neural marker for autism is still ongoing, yet new findings suggest that aberrant brain connectivity may be a promising candidate.

Lien vers le texte intégral (Open Access ou abonnement)

9. Mousavizadeh K, Askari M, Arian H, Gourjipour F, Nikpour AR, Tavafjadid M, Aryani O, Kamalidehghan B, Maroof HR, Houshmand M. {{Association of human mtDNA mutations with autism in Iranian patients}}. {Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences}. 2013 Oct;18(10):926.

Lien vers Pubmed

10. Nielsen JA, Zielinski BA, Fletcher PT, Alexander AL, Lange N, Bigler ED, Lainhart JE, Anderson JS. {{Abnormal lateralization of functional connectivity between language and default mode regions in autism}}. {Molecular autism}. 2014 Feb 6;5(1):8.

BACKGROUND: Lateralization of brain structure and function occurs in typical development, and abnormal lateralization is present in various neuropsychiatric disorders. Autism is characterized by a lack of left lateralization in structure and function of regions involved in language, such as Broca and Wernicke areas. METHODS: Using functional connectivity magnetic resonance imaging from a large publicly available sample (n = 964), we tested whether abnormal functional lateralization in autism exists preferentially in language regions or in a more diffuse pattern across networks of lateralized brain regions. RESULTS: The autism group exhibited significantly reduced left lateralization in a few connections involving language regions and regions from the default mode network, but results were not significant throughout left- and right-lateralized networks. There is a trend that suggests the lack of left lateralization in a connection involving Wernicke area and the posterior cingulate cortex associates with more severe autism. CONCLUSIONS: Abnormal language lateralization in autism may be due to abnormal language development rather than to a deficit in hemispheric specialization of the entire brain.

Lien vers le texte intégral (Open Access ou abonnement)

11. Suh J, Eigsti IM, Naigles L, Barton M, Kelley E, Fein D. {{Narrative Performance of Optimal Outcome Children and Adolescents with a History of an Autism Spectrum Disorder (ASD)}}. {J Autism Dev Disord}. 2014 Feb 6.

Autism Spectrum Disorders (ASDs) have traditionally been considered a lifelong condition; however, a subset of people makes such significant improvements that they no longer meet diagnostic criteria for an ASD. The current study examines whether these « optimal outcome » (OO) children and adolescents continue to have subtle pragmatic language deficits. The narratives of 15 OO individuals, 15 high-functioning individuals with an ASD (HFA), and 15 typically developing (TD) peers were evaluated. Despite average cognitive functioning, the ASD group produced narratives with fewer central « gist » descriptions, more ambiguous pronominal referents, idiosyncratic language, speech dysfluency (more repetitions and self-corrections), and were less likely to name story characters. The OO participants displayed only very subtle pragmatic and higher-level language deficits (idiosyncratic language and self-correction dysfluency).

Lien vers le texte intégral (Open Access ou abonnement)

12. Taurines R, Segura M, Schecklmann M, Albantakis L, Grunblatt E, Walitza S, Jans T, Lyttwin B, Haberhausen M, Theisen FM, Martin B, Briegel W, Thome J, Schwenck C, Romanos M, Gerlach M. {{Altered peripheral BDNF mRNA expression and BDNF protein concentrations in blood of children and adolescents with autism spectrum disorder}}. {Journal of neural transmission (Vienna, Austria : 1996)}. 2014 Feb 6.

Findings from molecular genetic studies and analyses of postmortem and peripheral tissue led to the hypothesis that neurotrophins-as crucial moderators of neuroplasticity-impact on the pathophysiology of autism spectrum disorder (ASD). The study projects aimed to complement former results on the role of brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family with fundamental impact on brain development and function. The purpose of this work was to investigate peripheral BDNF mRNA expression and BDNF protein concentrations in ASD as potential surrogates for the effects observed in the central nervous system. In a BDNF protein quantification study, serum concentrations were analyzed using Enzyme-Linked Immunosorbent Assays in 24 male patients with ASD, all with an IQ > 70 (age 13.9 +/- 3.0 years) and 20 age- and gender-matched healthy control subjects (age 14.4 +/- 2.1 years; p = 0.522). In a further independent project, a BDNF mRNA expression analysis, mRNA levels from total blood were assessed by quantitative real-time polymerase chain reaction in a sample of 16 male ASD patients (age 10.8 +/- 2.2), 15 age- and gender-matched healthy controls (age 12.1 +/- 2.2) and 15 patients with attention deficit hyperactivity disorder as a clinical control group (age 11.8 +/- 2.2; p = 0.207). In the protein quantification project, significantly decreased BDNF serum concentrations were found in ASD cases compared to healthy control children (t = -2.123, df = 42, p < 0.05). Analysis of covariance (ANCOVA) revealed this result in accordance with significant reductions in BDNF mRNA expression in ASD, observed in the mRNA expression study (F = 3.65; df = 2.43; p < 0.05); neither age nor IQ confounded the result, as indicated by ANCOVA (F = 3.961; df = 2.41; p < 0.05, eta 2 = 0.162). Our study projects supported the notion that neurotrophins are involved in the pathophysiology of ASD. Further studies may eventually contribute to the identification of distinct peripheral mRNA expression and protein concentration patterns possibly supporting diagnostic and therapeutic processes.

Lien vers le texte intégral (Open Access ou abonnement)

13. Tudor ME, Walsh CE, Mulder EC, Lerner MD. {{Pain as a predictor of sleep problems in youth with autism spectrum disorders}}. {Autism}. 2014 Feb 4.

Evidence suggests that pain interferes with sleep in youth with developmental disabilities. This study examined the relationship between pain and sleep problems in a sample of youth with parent-reported autism spectrum disorder (N = 62). Mothers reported on standardized measures of pain and sleep problems. Youth demonstrated atypically high levels of both observed pain and sleep problems. Pain predicted overall sleep disturbance and three specific sleep problems: sleep duration, parasomnias, and sleep-disordered breathing. These specific sleep problems were predicted by specific modalities of nonverbal pain communication (e.g. sleep duration problems were predicted by social communication of pain). Effects were consistent across probing of relevant moderators. These findings suggest that comprehensive assessment of both pain and sleep problems may provide important information for medical and behavioral treatment planning for youth with autism spectrum disorder.

Lien vers le texte intégral (Open Access ou abonnement)