Pubmed du 02/10/15

Pubmed du jour

2015-10-02 12:03:50

1. Barney CC, Feyma T, Beisang A, Symons FJ. {{Pain experience and expression in Rett syndrome: Subjective and objective measurement approaches}}. {J Dev Phys Disabil};2015 (Aug 1);27(4):417-429.

Rett syndrome (RTT) is associated with myriad debilitating health issues and significant motor and communicative impairments. Because of the former there is concern about the possibility of recurrent and chronic pain but because of the latter it remains difficult to determine what pain ‘looks like’ in RTT. This study investigated pain experience and expression using multiple complementary subjective and objective approaches among a clinical RTT sample. Following informed consent, 18 participants (all female) with RTT (mean age= 12.8 years, SD= 6.32) were characterized in terms of pain experience and interference, typical pain expression, and elicited pain behavior during a passive range of motion-like examination procedure. Parents completed the Dalhousie Pain Interview (DPI; pain type, frequency, duration, intensity), the Brief Pain Inventory (BPI; pain interference), and the Non-Communicating Children’s Pain Checklist – Revised (NCCPC-R; typical pain expression). A Pain Examination Procedure (PEP) was conducted and scored using the Pain and Discomfort Scale (PADS). The majority of the sample (89%) were reported to experience pain in the previous week which presented as gastrointestinal (n=8), musculoskeletal (n=5), and seizure related pain (n=5) that was intense (scored 0-10; M= 5.67, SD= 3.09) and long in duration (M= 25.22 hours, SD= 53.52). Numerous pain-expressive behaviors were inventoried (e.g., vocal, facial, mood/interaction changes) when parents reported their child’s typical pain behaviors and based on independent direct observation during a reliably coded pain exam. This study provides subjective and objective evidence that individuals with RTT experience recurring and chronic pain for which pain expression appears intact.

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2. Deng PY, Klyachko VA. {{Genetic upregulation of BK channel activity normalizes multiple synaptic and circuit defects in a mouse model of fragile X syndrome}}. {J Physiol};2015 (Oct 2)
Loss of Fragile X Mental Retardation Protein (FMRP) causes Fragile X Syndrome (FXS), yet the mechanisms underlying the pathophysiology of FXS are incompletely understood. Recent studies identified important new functions of FMRP in regulating neural excitability and synaptic transmission via both translation-dependent mechanisms and direct interactions of FMRP with a number of ion channels in the axons and presynaptic terminals. Among these presynaptic FMRP functions, FMRP interaction with BK channels, specifically their auxiliary beta4 subunit, regulates action potential waveform and glutamate release in hippocampal and cortical pyramidal neurons. Given the multitude of ion channels and mechanisms that mediate presynaptic FMRP actions, it remains unclear, however, to what extent FMRP-BK channel interactions contribute to synaptic and circuit defects in FXS. To examine this question, we generated Fmr1/beta4 double knock-out (dKO) mice to genetically upregulate BK channel activity in the absence of FMRP and determine its ability to normalize multilevel defects caused by FMRP loss. Single-channel analyses revealed that FMRP loss reduced BK channel open probability, and this defect was compensated in dKO mice. Furthermore, dKO mice exhibited normalized action potential duration, glutamate release and short-term dynamics during naturalistic stimulus trains in hippocampal pyramidal neurons. BK channel upregulation was also sufficient to correct excessive seizure susceptibility in an in vitro model of seizure activity in hippocampal slices. Our studies thus suggest that upregulation of BK channel activity normalizes multi-level deficits caused by FMRP loss. This article is protected by copyright. All rights reserved.

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3. Devinsky O, Asato M, Camfield P, Geller E, Kanner AM, Keller S, Kerr M, Kossoff EH, Lau H, Kothare S, Singh BK, Wirrell E. {{Delivery of epilepsy care to adults with intellectual and developmental disabilities}}. {Neurology};2015 (Sep 30)
Epilepsy is common in people with intellectual and developmental disabilities (IDD). In adulthood, patients with IDD and epilepsy (IDD-E) have neurologic, psychiatric, medical, and social challenges compounded by fragmented and limited care. With increasing neurologic disability, there is a higher frequency of epilepsy, especially symptomatic generalized and treatment-resistant epilepsies. The causes of IDD-E are increasingly recognized to be genetic based on chromosomal microarray analysis to identify copy number variants, gene panels (epilepsy, autism spectrum disorder, intellectual disability), and whole-exome sequencing. A specific genetic diagnosis may guide care by pointing to comorbid disorders and best therapy. Therapy to control seizures should be individualized, with drug selection based on seizure types, epilepsy syndrome, concomitant medications, and comorbid disorders. There are limited comparative antiepileptic drug data in the IDD-E population. Vagus nerve and responsive neural stimulation therapies and resective surgery should be considered. Among the many comorbid disorders that affect patients with IDD-E, psychiatric and sleep disorders are common but often unrecognized and typically not treated. Transition from holistic and coordinated pediatric to adult care is often a vulnerable period. Communication among adult health care providers is complex but essential to ensure best care when these patients are seen in outpatient, emergency room, and inpatient settings. We propose specific recommendations for minimum care standards for people with IDD-E.

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4. Griffin C, Lombardo MV, Auyeung B. {{Alexithymia in children with and without autism spectrum disorders}}. {Autism Res};2015 (Oct 1)
Alexithymia refers to pronounced difficulty in identifying and describing one’s own emotions and is associated with an externally oriented focus of thinking. Alexithymia is known to be much more common in adults with autism spectrum disorders (ASD) compared with the typically developing (TD) adult population. However, we know very little about alexithymia in young children with ASD and advancing our understanding of this topic may be of critical clinical and translational importance. Here, we present the first study to examine alexithymia in children with ASD. We find that alexithymia is substantially elevated in ASD on both self- and parent-report measures. Despite both measures being sensitive to on-average group differentiation, we find no evidence of correlation between such measures, indicating that children and their parents may be using different sources of information. Parent-rated alexithymia is also associated with increasing levels of autistic traits. Discrepancy between self and other alexithymia ratings are also associated with autistic traits, but only in ASD. These results underscore the idea that assessing alexithymia in ASD at younger ages may help identify important subgroups that have particular difficulties in the domain of emotion processing. Autism Res 2015. (c) 2015 International Society for Autism Research, Wiley Periodicals, Inc.

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5. Nestor MW, Phillips AW, Artimovich E, Nestor JE, Hussman JP, Blatt GJ. {{Human Inducible Pluripotent Stem Cells and Autism Spectrum Disorder: Emerging Technologies}}. {Autism Res};2015 (Oct 1)
Autism Spectrum Disorder (ASD) is a behaviorally defined neurodevelopmental condition. Symptoms of ASD cover the spectrum from mild qualitative differences in social interaction to severe communication and social and behavioral challenges that require lifelong support. Attempts at understanding the pathophysiology of ASD have been hampered by a multifactorial etiology that stretches the limits of current behavioral and cell based models. Recent progress has implicated numerous autism-risk genes but efforts to gain a better understanding of the underlying biological mechanisms have seen slow progress. This is in part due to lack of appropriate models for complete molecular and pharmacological studies. The advent of induced pluripotent stem cells (iPSC) has reinvigorated efforts to establish more complete model systems that more reliably identify molecular pathways and predict effective drug targets and candidates in ASD. iPSCs are particularly appealing because they can be derived from human patients and controls for research purposes and provide a technology for the development of a personalized treatment regimen for ASD patients. The pluripotency of iPSCs allow them to be reprogrammed into a number of CNS cell types and phenotypically screened across many patients. This quality is already being exploited in protocols to generate 2-dimensional (2-D) and three-dimensional (3-D) models of neurons and developing brain structures. iPSC models make powerful platforms that can be interrogated using electrophysiology, gene expression studies, and other cell-based quantitative assays. iPSC technology has limitations but when combined with other model systems has great potential for helping define the underlying pathophysiology of ASD. Autism Res 2015. (c) 2015 International Society for Autism Research, Wiley Periodicals, Inc.

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6. Papale LA, Zhang Q, Li S, Chen K, Keles S, Alisch RS. {{Genome-wide disruption of 5-hydroxymethylcytosine in a mouse model of autism}}. {Hum Mol Genet};2015 (Sep 30)
The autism spectrum disorders (ASD) comprise a broad group of behaviorally related neurodevelopmental disorders affecting as many as 1 in 68 children. The hallmarks of ASD consist of impaired social and communication interactions, pronounced repetitive behaviors and restricted patterns of interests. Family, twin, and epidemiological studies suggest a polygenetic and epistatic susceptibility model involving the interaction of many genes; however, the etiology of ASD is likely to be complex and include both epigenetic and environmental factors. 5-hydroxymethylcytosine (5hmC) is a novel environmentally sensitive DNA modification that is highly enriched in post-mitotic neurons and is associated with active transcription of neuronal genes. Here, we used an established chemical labeling and affinity purification method coupled with high-throughput sequencing technology to generate a genome-wide profile of striatal 5hmC in an autism mouse model (Cntnap2-/- mice) and found that at 9 weeks of age the Cntnap2-/- mice have a genome-wide disruption in 5hmC, primarily in genic regions and repetitive elements. Annotation of differentially hydroxymethylated regions (DhMRs) to genes revealed a significant overlap with known ASD genes (e.g., Nrxn1 and Reln) that carried an enrichment of neuronal ontological functions, including axonogenesis and neuron projection morphogenesis. Finally, sequence motif predictions identified associations with transcription factors that have a high correlation with important genes in neuronal developmental and functional pathways. Together, our data implicate a role for 5hmC-mediated epigenetic modulation in the pathogenesis of autism and represent a critical step toward understanding the genome-wide molecular consequence of the Cntnap2 mutation, which results in an autism-like phenotype.

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7. Robertson AE, David RSR. {{The sensory experiences of adults with autism spectrum disorder: A qualitative analysis}}. {Perception};2015;44(5):569-586.

It has been well established that individuals with autism spectrum disorder report unusual experiences with sensory stimuli compared with typically developing individuals. However, there is a paucity of research exploring the nature of such experiences. A focus group was conducted with six adults with a diagnosis of autism or Asperger syndrome. Data were coded and analysed using an inductive, qualitative thematic analysis. Four main themes encompassing both positive and negative sensory experiences emerged from these data: (a) the importance of particular aspects of stimuli in their perception, (b) the importance of having control over stimuli, (c) how emotions/mental states could impact/be impacted by sensory stimuli, and (d) physical responses to stimuli. These data are discussed alongside extant literature. Limitations, possible implications, and potential directions of future research are also discussed.

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8. Ross AK. {{The puzzling aspects of anesthesia and autism spectrum disorder}}. {Paediatr Anaesth};2015 (Nov);25(11):1072-1073.

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9. Son JS, Zheng LJ, Rowehl LM, Tian X, Zhang Y, Zhu W, Litcher-Kelly L, Gadow KD, Gathungu G, Robertson CE, Ir D, Frank DN, Li E. {{Comparison of Fecal Microbiota in Children with Autism Spectrum Disorders and Neurotypical Siblings in the Simons Simplex Collection}}. {PLoS One};2015;10(10):e0137725.

In order to assess potential associations between autism spectrum disorder (ASD) phenotype, functional GI disorders and fecal microbiota, we recruited simplex families, which had only a single ASD proband and neurotypical (NT) siblings, through the Simons Simplex Community at the Interactive Autism Network (SSC@IAN). Fecal samples and metadata related to functional GI disorders and diet were collected from ASD probands and NT siblings of ASD probands (age 7-14). Functional gastrointestinal disorders (FGID) were assessed using the parent-completed ROME III questionnaire for pediatric FGIDs, and problem behaviors were assessed using the Child Behavior Check List (CBCL). Targeted quantitative polymerase chain reaction (qPCR) assays were conducted on selected taxa implicated in ASD, including Sutterella spp., Bacteroidetes spp. and Prevotella spp. Illumina sequencing of the V1V2 and the V1V3 regions of the bacterial 16S rRNA genes from fecal DNA was performed to an average depth of 208,000 and 107,000 high-quality reads respectively. Twenty-five of 59 ASD children and 13 of 44 NT siblings met ROME III criteria for at least one FGID. Functional constipation was more prevalent in ASD (17 of 59) compared to NT siblings (6 of 44, P = 0.035). The mean CBCL scores in NT siblings with FGID, ASD children with FGID and ASD without FGID were comparably higher (58-62 vs. 44, P < 0.0001) when compared to NT children without FGID. There was no significant difference in macronutrient intake between ASD and NT siblings. There was no significant difference in ASD severity scores between ASD children with and without FGID. No significant difference in diversity or overall microbial composition was detected between ASD children with NT siblings. Exploratory analysis of the 16S rRNA sequencing data, however, identified several low abundance taxa binned at the genus level that were associated with ASD and/or first order ASD*FGID interactions (FDR <0.1).

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