1. Greffou S, Bertone A, Hahler EM, Hanssens JM, Mottron L, Faubert J. {{Postural Hypo-Reactivity in Autism is Contingent on Development and Visual Environment: A Fully Immersive Virtual Reality Study}}. {J Autism Dev Disord};2011 (Jul 13)
Although atypical motor behaviors have been associated with autism, investigations regarding their possible origins are scarce. This study assessed the visual and vestibular components involved in atypical postural reactivity in autism. Postural reactivity and stability were measured for younger (12-15 years) and older (16-33 years) autistic participants in response to a virtual tunnel oscillating at different frequencies. At the highest oscillation frequency, younger autistic participants showed significantly less instability compared to younger typically-developing participants; no such group differences were evidenced for older participants. Additionally, no significant differences in postural behavior were found between all 4 groups when presented with static or without visual information. Results confirm that postural hypo-reactivity to visual information is present in autism, but is contingent on both visual environment and development.
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2. Herbert MR. {{SHANK3, the synapse, and autism}}. {N Engl J Med};2011 (Jul 14);365(2):173-175.
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3. Holtmann M, Steiner S, Hohmann S, Poustka L, Banaschewski T, Bolte S. {{Neurofeedback in autism spectrum disorders}}. {Dev Med Child Neurol};2011 (Jul 14)
Aim To review current studies on the effectiveness of neurofeedback as a method of treatment of the core symptoms of autism spectrum disorders (ASD). Method Studies were selected based on searches in PubMed, Ovid MEDLINE, EMBASE, ERIC, and CINAHL using combinations of the following keywords: ‘Neurofeedback’ OR ‘EEG Biofeedback’ OR ‘Neurotherapy’ OR ‘Mu-Rhythm’ OR ‘SMR’ AND ‘Autism’ OR ‘Autism Spectrum Disorder’ OR ‘Pervasive Developmental Disorder’. Results The existing evidence does not support the use of neurofeedback in the treatment of ASD. Studies with outcomes in favour of neurofeedback might be showing an improvement in comorbid attention-deficit-hyperactivity disorder symptoms rather than a true improvement in core ASD symptoms. Interpretation Limitations of this review are those inherent in the studies available, including small sample size, short duration, variable diagnostic criteria, and insufficient control interventions, all causing a lack of generalizability.
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4. Jeong JW, Kumar A, Sundaram SK, Chugani HT, Chugani DC. {{Sharp Curvature of Frontal Lobe White Matter Pathways in Children with Autism Spectrum Disorders: Tract-Based Morphometry Analysis}}. {AJNR Am J Neuroradiol};2011 (Jul 14)
BACKGROUND AND PURPOSE: Because we had previously observed geometric changes of frontal lobe association pathways in children with ASD, in the present study we analyzed the curvature of these white matter pathways by using an objective TBM analysis. MATERIALS AND METHODS: Diffusion tensor imaging was performed in 32 children with ASD and 14 children with typical development. Curvature, FA, AD, and RD of bilateral AF, UF, and gCC were investigated by using the TBM group analysis assessed by P(FDR) for multiple comparisons. RESULTS: Significantly higher curvatures were found in children with ASD, especially at the parietotemporal junction for AF (left, P(FDR) < .001; right, P(FDR) < .01), at the frontotemporal junction for UF (left, P(FDR) < .005; right, P(FDR) < .03), and at the midline of the gCC (P(FDR) < .0001). RD was significantly higher in children with ASD at the same bending regions of AF (left, P(FDR) < .03, right, P(FDR) < .02), UF (left, P(FDR) < .04), and gCC (P(FDR) < .01). CONCLUSIONS: Higher curvature and curvature-dependent RD changes in children with ASD may be the result of higher attenuation of thinner axons in these frontal lobe tracts.
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5. Keri S, Benedek G. {{Fragile X protein expression is linked to visual functions in healthy male volunteers}}. {Neuroscience};2011 (Jul 1)
Fragile X syndrome (FXS) is characterized by the impairment of the magnocellular/dorsal visual system. In this study, we explored how fragile X protein (FMRP) expression may affect visual functions in healthy participants. The percentage of FMRP-positive lymphocytes was measured using a rapid antibody test in blood smears of 100 male volunteers. CGG triplet expansion was also determined. Results revealed that participants with fewer FMRP-positive lymphocytes exhibited lower performances on tests biasing information processing toward the magnocellular pathway and dorsal visual stream (contrast sensitivity at low spatial/high temporal frequency and motion coherence). It was not observed in the case of tests biasing information processing toward the parvocellular pathway and ventral stream (contrast sensitivity at high spatial/low temporal frequency and form coherence). These results suggest that healthy persons with lower peripheral FMRP expression display a visual phenotype similar to that described in patients with FXS.
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6. Liu X, Malenfant P, Reesor C, Lee A, Hudson ML, Harvard C, Qiao Y, Persico AM, Cohen IL, Chudley AE, Forster-Gibson C, Rajcan-Separovic E, Lewis MS, Holden JJ. {{2p15-p16.1 microdeletion syndrome: molecular characterization and association of the OTX1 and XPO1 genes with autism spectrum disorders}}. {Eur J Hum Genet};2011 (Jul 13)
Reports of unrelated individuals with autism spectrum disorder (ASD) and similar clinical features having overlapping de novo interstitial deletions at 2p15-p16.1 suggest that this region harbors a gene(s) important to the development of autism. We molecularly characterized two such deletions, selecting two genes in this region, exportin 1 (XPO1) and orthodenticle homolog 1 (OTX1) for association studies in three North American cohorts (Autism Spectrum Disorder – Canadian American Research Consortium (ASD-CARC), New York, and Autism Genetic Resource Exchange (AGRE)) and one Italian cohort (Societa Italiana per la Ricerca e la Formazione sull’Autismo (SIRFA)) of families with ASD. In XPO1, rs6735330 was associated with autism in all four cohorts (P<0.05), being significant in ASD-CARC cohorts (P-value following false discovery rate correction for multiple testing (P(FDR))=1.29 x 10(-5)), the AGRE cohort (P(FDR)=0.0011) and the combined families (P(FDR)=2.34 x 10(-9)). Similarly, in OTX1, rs2018650 and rs13000344 were associated with autism in ASD-CARC cohorts (P(FDR)=8.65 x 10(-7) and 6.07 x 10(5), respectively), AGRE cohort (P(FDR)=0.0034 and 0.015, respectively) and the combined families (P(FDR)=2.34 x 10(-9) and 0.00017, respectively); associations were marginal or insignificant in the New York and SIRFA cohorts. A significant association (P(FDR)=2.63 x 10(-11)) was found for the rs2018650G-rs13000344C haplotype. The above three SNPs were associated with severity of social interaction and verbal communication deficits and repetitive behaviors (P-values <0.01). No additional deletions were identified following screening of 798 ASD individuals. Our results indicate that deletion 2p15-p16.1 is not commonly associated with idiopathic ASD, but represents a novel contiguous gene syndrome associated with a constellation of phenotypic features (autism, intellectual disability, craniofacial/CNS dysmorphology), and that XPO1 and OXT1 may contribute to ASD in 2p15-p16.1 deletion cases and non-deletion cases of ASD mapping to this chromosome region.European Journal of Human Genetics advance online publication, 13 July 2011; doi:10.1038/ejhg.2011.112.
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7. Obrenovich ME, Shamberger RJ, Lonsdale D. {{Altered Heavy Metals and Transketolase Found in Autistic Spectrum Disorder}}. {Biol Trace Elem Res};2011 (Jul 14)
Autism and autism spectrum disorder (ASD) are developmental brain disorders with complex, obscure, and multifactorial etiology. Our recent clinical survey of patient records from ASD children under the age of 6 years and their age-matched controls revealed evidence of abnormal markers of thiol metabolism, as well as a significant alteration in deposition of several heavy metal species, particularly arsenic, mercury, copper, and iron in hair samples between the groups. Altered thiol metabolism from heavy metal toxicity may be responsible for the biochemical alterations in transketolase, and are mechanisms for oxidative stress production, dysautonomia, and abnormal thiamine homeostasis. It is unknown why the particular metals accumulate, but we suspect that children with ASD may have particular trouble excreting thiol-toxic heavy metal species, many of which exist as divalent cations. Accumulation or altered mercury clearance, as well as concomitant oxidative stress, arising from redox-active metal and arsenic toxicity, offers an intriguing component or possible mechanism for oxidative stress-mediated neurodegeneration in ASD patients. Taken together, these factors may be more important to the etiology of this symptomatically diverse disease spectrum and may offer insights into new treatment approaches and avenues of exploration for this devastating and growing disease.
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8. Scheel C, Rotarska-Jagiela A, Schilbach L, Lehnhardt FG, Krug B, Vogeley K, Tepest R. {{Imaging derived cortical thickness reduction in high-functioning autism: Key regions and temporal slope}}. {Neuroimage};2011 (Jul 1)
Cortical thickness (CT) changes possibly contribute to the complex symptomatology of autism. The aberrant developmental trajectories underlying such differences in certain brain regions and their continuation in adulthood are a matter of intense debate. We studied 28 adults with high-functioning autism (HFA) and 28 control subjects matched for age, gender, IQ and handedness. A surface-based whole brain analysis utilizing FreeSurfer was employed to detect CT differences between the two diagnostic groups and to investigate the time course of age-related changes. Direct comparison with control subjects revealed thinner cortex in HFA in the posterior superior temporal sulcus (pSTS) of the left hemisphere. Considering the time course of CT development we found clusters around the pSTS and cuneus in the left and the paracentral lobule in the right hemisphere to be thinner in HFA with comparable age-related slopes in patients and controls. Conversely, we found clusters around the supramarginal gyrus and inferior parietal lobule (IPL) in the left and the precentral and postcentral gyrus in the right hemisphere to be thinner in HFA, but with different age-related slopes in patients and controls. In the latter regions CT showed a steady decrease in controls but no analogous thinning in HFA. CT analyses contribute in characterizing neuroanatomical correlates of HFA. Reduced CT is present in brain regions involved in social cognition. Furthermore, our results demonstrate that aberrant brain development leading to such differences is proceeding throughout adulthood. Discrepancies in prior morphometric studies may be induced by the complex time course of cortical changes.
