1. Chen R, Jiao Y, Herskovits EH. {{Structural MRI in Autism Spectrum Disorder}}. {Pediatr Res}. 2011 Feb 1.
Magnetic-resonance (MR) examination provides a powerful tool for investigating brain structural changes in children with Autism Spectrum Disorder (ASD). We review recent advances in the understanding of structural-MR correlates of ASD. We summarize findings from studies based on voxel-based morphometry, surface-based morphometry, and tensor-based morphometry, and diffusion-tensor imaging. Finally, we discuss diagnostic models of ASD, based on MR-derived features. ABBREVIATIONS::
2. Constantino JN. {{The Quantitative Nature of Autistic Social Impairment}}. {Pediatr Res}. 2011 Feb 1.
Autism, like intellectual disability, represents the severe end of a continuous distribution of developmental impairments that occur in nature, that are highly inherited, and that are orthogonally related to other parameters of development. A paradigm shift in understanding the core social abnormality of autism as a quantitative trait rather than as a categorically-defined condition has key implications for diagnostic classification, the measurement of change over time, the search for underlying genetic and neurobiologic mechanisms, and public health efforts to identify and support affected children. Here a recent body of research in genetics and epidemiology is presented to examine a dimensional reconceptualization of autistic social impairment-as manifested in clinical autistic syndromes, the broader autism phenotype, and normal variation in the general population. It illustrates how traditional categorical approaches to diagnosis may lead to misclassification of subjects (especially girls and mildly affected boys in multiple-incidence autism families), which can be particularly damaging to biological studies, and proposes continued efforts to derive a standardized quantitative system by which to characterize this family of conditions. ABBREVIATIONS:
3. Frye RE, Rossignol DA. {{Mitochondrial dysfunction can connect the diverse medical symptoms associated with autism spectrum disorders}}. {Pediatr Res}. 2011 Feb 1.
Autism spectrum disorder (ASD) is a devastating neurodevelopmental disorder. Over the last decade, evidence has emerged that some children with ASD suffer from undiagnosed co-morbid medical conditions. One of the medical disorders that has been consistently associated with ASD is mitochondrial dysfunction. Individuals with mitochondrial disorders without concomitant ASD manifest dysfunction in multiple high energy organ systems, such as the central nervous, muscular and gastrointestinal systems. Interestingly, these are the identical organ systems affected in a significant number of children with ASD. This finding raises the possibility that mitochondrial dysfunction may be one of the keys that explains the many diverse symptoms observed in some children with ASD. This manuscript will review the importance of mitochondria in human health and disease, the evidence for mitochondrial dysfunction in ASD, the potential role of mitochondrial dysfunction in the co-morbid medical conditions associated with ASD, and how mitochondrial dysfunction can bridge the gap for understanding how these seemingly disparate medical conditions are related. We also review the limitation of this evidence and other possible explanations for these findings. This new understanding of ASD should provide researchers a pathway for understanding the etiopathogenesis of ASD and clinicians the potential to develop medical therapies. ABBREVIATION LIST:
4. Kohls G, Peltzer J, Schulte-Ruther M, Kamp-Becker I, Remschmidt H, Herpertz-Dahlmann B, et al. {{Atypical Brain Responses to Reward Cues in Autism as Revealed by Event-Related Potentials}}. {J Autism Dev Disord}. 2011 Feb 3.
Social motivation deficit theories suggest that children with autism do not properly anticipate and appreciate the pleasure of social stimuli. In this study, we investigated event-related brain potentials evoked by cues that triggered social versus monetary reward anticipation in children with autism. Children with autism showed attenuated P3 activity in response to cues associated with a timely reaction to obtain a reward, irrespective of reward type. We attribute this atypical P3 activity in response to reward cues as reflective of diminished motivated attention to reward signals, a possible contributor to reduced social motivation in autism. Thus, our findings suggest a general reward processing deficit rather than a specific social reward dysfunction in autism.
5. Marco EJ, Hinkley LB, Hill SS, Nagarajan SS. {{Sensory Processing in Autism: A Review of Neurophysiologic Findings}}. {Pediatr Res}. 2011 Feb 1.
Atypical sensory-based behaviors are a ubiquitous feature of autism spectrum disorders (ASD). In this article, we review the neural underpinnings of sensory processing in autism by reviewing the literature on neurophysiological responses to auditory, tactile, and visual stimuli in autistic individuals. We review studies of unimodal sensory processing and multi-sensory integration that use a variety of neuroimaging techniques, including: electroencephalography (EEG), magnetoencephalography (MEG), and functional Magnetic Resonance Imaging (fMRI). We then explore the impact of covert and overt attention on sensory processing. With additional characterization, neurophysiologic profiles of sensory processing in ASD may serve as valuable biomarkers for diagnosis and monitoring of therapeutic interventions for autism and reveal potential strategies and target brain regions for therapeutic interventions. ABBREVIATIONS:
6. Meyer U, Feldon J, Dammann O. {{Schizophrenia and autism: both shared and disorder-specific pathogenesis via perinatal inflammation?}}. {Pediatr Res}. 2011 Feb 1.
Prenatal exposure to infection and subsequent inflammatory responses have been implicated in the etiology of schizophrenia and autism. In this review, we summarize current evidence from human and animal studies supporting the hypothesis that the pathogenesis of these two disorders is linked via exposure to inflammation at early stages of development. Moreover, we propose a hypothetical model in which inflammatory mechanisms may account for multiple shared and disorder-specific pathological characteristics of both entities. In essence, our model suggests that acute neuroinflammation during early fetal development may be relevant for the induction of psychopathological and neuropathological features shared by schizophrenia and autism, while post-acute latent and persistent inflammation may contribute to schizophrenia- and autism-specific phenotypes, respectively. ABBREVIATIONS::
7. Patterson PH. {{Modeling Autistic Features in Animals}}. {Pediatr Res}. 2011 Feb 1.
A variety of features of autism can be simulated in rodents, including the core behavioral hallmarks of stereotyped and repetitive behaviors, and deficits in social interaction and communication. Other behaviors frequently found in autism spectrum disorders (ASD) such as neophobia, enhanced anxiety, abnormal pain sensitivity and eye blink conditioning, disturbed sleep patterns, seizures, and deficits in sensorimotor gating are also present in some of the animal models. Neuropathology and some characteristic neurochemical changes that are frequently seen in autism, as well as alterations in the immune status in the brain and periphery are also found in some of the models. Several known environmental risk factors for autism have been successfully established in rodents, including maternal infection and maternal valproate administration. Also under investigation are a number of mouse models based on genetic variants associated with autism or on syndromic disorders with autistic features. This review briefly summarizes recent developments in this field, highlighting models with face and/or construct validity, and noting the potential for investigation of pathogenesis and early progress towards clinical testing of potential therapeutics. Wherever possible, reference is made to reviews rather than primary articles. ABBREVIATIONS:
8. Susanne B. {{[Sure, Glenn Gould must have had an autism spectrum disorder]}}. {Lakartidningen}. 2010 Dec 1-7;107(48):3074.
9. Walsh KM, Bracken MB. {{Copy number variation in the dosage-sensitive 16p11.2 interval accounts for only a small proportion of autism incidence: A systematic review and meta-analysis}}. {Genet Med}. 2011 Feb 1.
PURPOSE:: Autism is one of the most heritable complex disorders, but the genetic etiology of autism spectrum disorders is unexplained in approximately 90% of cases. Highly penetrant microdeletions and microduplications of 16p11.2 contribute to the pathogenesis of autism spectrum disorder, but the extent to which these variants account for the total burden of idiopathic autism spectrum disorders has not been systematically investigated. METHODS:: A systematic literature review and meta-analysis were performed to determine the prevalence of these variants among individuals diagnosed with autism spectrum disorders. A planned subgroup analysis was conducted to assess prevalence differences between sporadic and familial autism spectrum disorder cases. RESULTS:: In the combined analysis of 3613 idiopathic autism spectrum disorder cases from seven studies, the meta-analytic prevalence of these microdeletions and microduplications was 0.76% (95% CI, 0.51-1.12%). When stratified by copy number variant-type, the prevalence of microdeletions was 0.50% (95% CI, 0.31-0.82%) and the prevalence of microduplications was 0.28% (95% CI, 0.14-0.56%). Sporadic autism spectrum disorder cases showed only a slightly higher prevalence than familial cases. CONCLUSION:: The number needed to test to identify one such variant is 132 patients (95% CI, 89-198). Such information, especially as it pertains to diagnostic yield in genetic testing, should prove useful to clinicians considering chromosomal microarray analysis in subjects with autism spectrum disorders.
10. Zaroff CM, Uhm SY. {{Prevalence of autism spectrum disorders and influence of country of measurement and ethnicity}}. {Soc Psychiatry Psychiatr Epidemiol}. 2011 Feb 4.
BACKGROUND: The prevalence of autism spectrum disorders (ASD) is generally somewhat lower in countries outside of North America and Europe. While there are culture-specific patterns of social cognitive processing, the influence of such patterns upon ASD prevalence has yet to be fully explored. METHODS: A comprehensive literature search for original articles reporting ASD prevalence was undertaken. Data across studies were compared with a particular focus on variables of geographic residence and ethnicity. RESULTS: ASD prevalence varies across countries in a manner that appears to suggest that the greatest influence is due to methodological variables. The nature of a potential influence of culture-specific patterns of cognitive processing upon prevalence remains unknown. The available little data concerning the association between ethnicity and prevalence are limited to studies within the United States (US) showing differences in children of Hispanic descent relative to Whites, a finding for which a definitive explanation is lacking. CONCLUSIONS: Available evidence suggests that methodological factors are largely responsible for differences in ASD prevalence across studies. The much discussed increase in prevalence in ASD has been observed worldwide, suggesting that the refinement of diagnostic methodology and/or broadening diagnostic concept is not limited to Western countries. Within individual countries, only in the US has the influence of ethnicity upon ASD prevalence been examined in depth. In the US, children of Hispanic descent have the lowest prevalence of ASD, while Whites tend to have the highest prevalence of ASD. Hypothesized etiological factors for such prevalence differences include methodological factors, socioeconomic variables, and bias.
