1. Cheung C, McAlonan GM, Fung YY, Fung G, Yu KK, Tai KS, Sham PC, Chua SE. {{MRI study of minor physical anomaly in childhood autism implicates aberrant neurodevelopment in infancy}}. {PLoS One};2011;6(6):e20246.
BACKGROUND: MPAs (minor physical anomalies) frequently occur in neurodevelopmental disorders because both face and brain are derived from neuroectoderm in the first trimester. Conventionally, MPAs are measured by evaluation of external appearance. Using MRI can help overcome inherent observer bias, facilitate multi-centre data acquisition, and explore how MPAs relate to brain dysmorphology in the same individual. Optical MPAs exhibit a tightly synchronized trajectory through fetal, postnatal and adult life. As head size enlarges with age, inter-orbital distance increases, and is mostly completed before age 3 years. We hypothesized that optical MPAs might afford a retrospective ‘window’ to early neurodevelopment; specifically, inter-orbital distance increase may represent a biomarker for early brain dysmaturation in autism. METHODS: We recruited 91 children aged 7-16; 36 with an autism spectrum disorder and 55 age- and gender-matched typically developing controls. All children had normal IQ. Inter-orbital distance was measured on T1-weighted MRI scans. This value was entered into a voxel-by-voxel linear regression analysis with grey matter segmented from a bimodal MRI data-set. Age and total brain tissue volume were entered as covariates. RESULTS: Intra-class coefficient for measurement of the inter-orbital distance was 0.95. Inter-orbital distance was significantly increased in the autism group (p = 0.03, 2-tailed). The autism group showed a significant relationship between inter-orbital distance grey matter volume of bilateral amygdalae extending to the unci and inferior temporal poles. CONCLUSIONS: Greater inter-orbital distance in the autism group compared with healthy controls is consistent with infant head size expansion in autism. Inter-orbital distance positively correlated with volume of medial temporal lobe structures, suggesting a link to « social brain » dysmorphology in the autism group. We suggest these data support the role of optical MPAs as a « fossil record » of early aberrant neurodevelopment, and potential biomarker for brain dysmaturation in autism.
2. Egawa J, Watanabe Y, Kitamura H, Endo T, Tamura R, Hasegawa N, Someya T. {{Reduced thalamus volume in non-right-handed male patients with autism spectrum disorders}}. {Psychiatry Clin Neurosci};2011 (Jun);65(4):395.
3. Ghanizadeh A. {{Can Tactile Sensory Processing Differentiate Between Children with Autistic Disorder and Asperger’s Disorder?}}. {Innov Clin Neurosci};2011 (May);8(5):25-30.
OBJECTIVE: There are debates whether autistic disorder (autism) and Asperger’s disorder are two distinct disorders. Moreover, interventional sensory occupational therapy should consider the clinical characteristics of patients. Already, commonalities and differences between Asperger’s disorder and autistic disorder are not well studied. The aim of this study is to compare tactile sensory function of children with autistic disorder and children with Asperger’s disorder. METHODS: Tactile sensory function was compared between 36 children with autism and 19 children with Asperger’s disorder. The two disorders were diagnosed based on Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision. The parent-reported Tactile Dysfunction Checklist was used to assess the three aspects of hypersensitivity, hyposensitivity, and poor tactile perception and discrimination. Developmental coordination was also assessed. RESULTS: Developmental coordination problems total score was not associated with group. The mean (standard deviation) score of tactile hyper-responsivity was not different between the groups. Tactile hyporesponsivity and poor tactile perception and discrimination scores were statistically higher in autistic disorder than Asperger’s disorder group. CONCLUSION: These results for the first time indicated that at least some aspects of tactile perception can differentiate these two disorders. Children with autistic disorder have more tactile sensory seeking behaviors than children with Asperger’s disorder. Moreover, the ability of children with autistic disorder for tactile discrimination and sensory perception is less than those with Asperger’s disorder. Interventional sensory therapy in children with autistic disorder should have some characteristics that can be different and specific for children with Asperger’s disorder. Formal intelligence quotient testing was not performed on all of the children evaluated, which is a limitation to this study. In some cases, a clinical estimation of intelligence quotient was given, which limits the conclusions that can be drawn from the data. Additional research using formal intelligence quotient testing on all of the subjects should be performed in order to draw more concrete conclusions.
4. Voineskos AN, Lett TA, Lerch JP, Tiwari AK, Ameis SH, Rajji TK, Muller DJ, Mulsant BH, Kennedy JL. {{Neurexin-1 and frontal lobe white matter: an overlapping intermediate phenotype for schizophrenia and autism spectrum disorders}}. {PLoS One};2011;6(6):e20982.
BACKGROUND: Structural variation in the neurexin-1 (NRXN1) gene increases risk for both autism spectrum disorders (ASD) and schizophrenia. However, the manner in which NRXN1 gene variation may be related to brain morphology to confer risk for ASD or schizophrenia is unknown. METHOD/PRINCIPAL FINDINGS: 53 healthy individuals between 18-59 years of age were genotyped at 11 single nucleotide polymorphisms of the NRXN1 gene. All subjects received structural MRI scans, which were processed to determine cortical gray and white matter lobar volumes, and volumes of striatal and thalamic structures. Each subject’s sensorimotor function was also assessed. The general linear model was used to calculate the influence of genetic variation on neural and cognitive phenotypes. Finally, in silico analysis was conducted to assess potential functional relevance of any polymorphisms associated with brain measures. A polymorphism located in the 3′ untranslated region of NRXN1 significantly influenced white matter volumes in whole brain and frontal lobes after correcting for total brain volume, age and multiple comparisons. Follow-up in silico analysis revealed that this SNP is a putative microRNA binding site that may be of functional significance in regulating NRXN1 expression. This variant also influenced sensorimotor performance, a neurocognitive function impaired in both ASD and schizophrenia. CONCLUSIONS: Our findings demonstrate that the NRXN1 gene, a vulnerability gene for SCZ and ASD, influences brain structure and cognitive function susceptible in both disorders. In conjunction with our in silico results, our findings provide evidence for a neural and cognitive susceptibility mechanism by which the NRXN1 gene confers risk for both schizophrenia and ASD.
5. Witter FR. {{Does treatment of premature labor with terbutaline increase the risk of autism spectrum disorders?}}. {Am J Obstet Gynecol};2011 (May 14)
