1. Allely CS, Gillberg C, Wilson P. {{Neurobiological abnormalities in the first few years of life in individuals later diagnosed with Autistic Spectrum Disorder: A review of recent data}}. {Behav Neurol}. 2013.
BACKGROUND: Despite the widely-held understanding that the biological changes that lead to autism usually occur during prenatal life, there has been relatively little research into the functional development of the brain during early infancy in individuals later diagnosed with autism spectrum disorder (ASD). OBJECTIVE: This review explores the studies over the last three years which have investigated differences in various brain regions in individuals with ASD or who later go on to receive a diagnosis of ASD. METHODS: We used PRISMA guidelines and selected published articles reporting any neurological abnormalities in very early childhood in individuals with or later diagnosed with ASD. RESULTS: Various brain regions are discussed including; the amygdala; cerebellum; frontal cortex and lateralised abnormalities of the temporal cortex during language processing. This review discusses studies investigating head circumference, electrophysiological markers and inter-hemispheric synchronisation. All the recent findings from the beginning of 2009 across these different aspects of defining neurological abnormalities are discussed in light of earlier findings. CONCLUSIONS: The studies across these different areas reveal the existence of atypicalities in the first year of life, well before ASD is reliably diagnosed. Cross-disciplinary approaches are essential to elucidate the pathophysiological sequence of events that lead to ASD.
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2. Cutting J. {{Autism and the brain: neurophenomenological interpretation}}. {Cogn Neuropsychiatry}. 2013.
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3. Delmonte S, Gallagher L, O’Hanlon E, McGrath J, Balsters JH. {{Functional and structural connectivity of frontostriatal circuitry in Autism Spectrum Disorder}}. {Front Hum Neurosci}. 2013; 7: 430.
Abnormalities in frontostriatal circuitry potentially underlie the two core deficits in Autism Spectrum Disorder (ASD); social interaction and communication difficulties and restricted interests and repetitive behaviors. Whilst a few studies have examined connectivity within this circuitry in ASD, no previous study has examined both functional and structural connectivity within the same population. The present study provides the first exploration of both functional and structural frontostriatal connectivity in ASD. Twenty-eight right-handed Caucasian male ASD (17.28 +/- 3.57 years) and 27 right-handed male, age and IQ matched controls (17.15 +/- 3.64 years) took part in the study. Resting state functional connectivity was carried out on 21 ASD and control participants, and tractography was carried out on 22 ASD and 24 control participants, after excluding subjects for excessive motion and poor data quality. Functional connectivity analysis was carried out between the frontal cortex and striatum after which tractography was performed between regions that showed significant group differences in functional connectivity. The ASD group showed increased functional connectivity between regions in the frontal cortex [anterior cingulate cortex (ACC), middle frontal gyrus (MFG), paracingulate gyrus (Pcg) and orbitofrontal cortex (OFC)], and striatum [nucleus accumbens (NAcc) and caudate]. Increased functional connectivity between ACC and caudate was associated with deactivation to social rewards in the caudate, as previously reported in the same participants. Greater connectivity between the right MFG and caudate was associated with higher restricted interests and repetitive behaviors and connectivity between the bilateral Pcg and NAcc, and the right OFC and NAcc, was negatively associated with social and communicative deficits. Although tracts were reliably constructed for each subject, there were no group differences in structural connectivity. Results are in keeping with previously reported increased corticostriatal functional connectivity in ASD.
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4. Duerden EG, Taylor MJ, Soorya LV, Wang T, Fan J, Anagnostou E. {{Neural correlates of inhibition of socially relevant stimuli in adults with autism spectrum disorder}}. {Brain Res}. 2013.
Adults with autism spectrum disorder (ASD) can demonstrate difficulties with inhibiting inappropriate social responses. Presently, little research has utilized socially relevant stimuli to explore the modulatory effects of emotion on cognitive control in this population. To assess neural mechanisms of inhibiting social stimuli, we presented images of happy or sad facial expressions in a Go/NoGo task to unmedicated adults with ASD and to control during functional magnetic resonance imaging (fMRI). Groups did not differ on behavioral measures. Brain activation in response to NoGo vs. Go trials revealed differing regional patterns of activation within groups. Controls recruited brain regions involved in inhibition (dorsal- [DLPFC] and ventro-lateral prefrontal cortices [VLPFC], anterior cingulate cortex [ACC]), response suppression (parietal lobe), interoceptive awareness (insula), and also the fusiform and middle temporal gyri. Adults with ASD only recruited the VLPFC and fusiform gyrus, and weakly activated the ACC and insula. Between-group comparisons indicated that controls activated the DLPFC, while adults with ASD relied on the VLPFC and the fusiform gyrus to inhibit responses. Adults with ASD may have relied more on visual association cortex, possibly as a means of recruiting additional neural processes that could act as a compensatory mechanism.
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5. Edgar JC, Khan SY, Blaskey L, Chow VY, Rey M, Gaetz W, Cannon KM, Monroe JF, Cornew L, Qasmieh S, Liu S, Welsh JP, Levy SE, Roberts TP. {{Neuromagnetic Oscillations Predict Evoked-Response Latency Delays and Core Language Deficits in Autism Spectrum Disorders}}. {J Autism Dev Disord}. 2013.
Previous studies have observed evoked response latency as well as gamma band superior temporal gyrus (STG) auditory abnormalities in individuals with autism spectrum disorders (ASD). A limitation of these studies is that associations between these two abnormalities, as well as the full extent of oscillatory phenomena in ASD in terms of frequency and time, have not been examined. Subjects were presented pure tones at 200, 300, 500, and 1,000 Hz while magnetoencephalography assessed activity in STG auditory areas in a sample of 105 children with ASD and 36 typically developing controls (TD). Findings revealed a profile such that auditory STG processes in ASD were characterized by pre-stimulus abnormalities across multiple frequencies, then early high-frequency abnormalities followed by low-frequency abnormalities. Increased pre-stimulus activity was a ‘core’ abnormality, with pre-stimulus activity predicting post-stimulus neural abnormalities, group membership, and clinical symptoms (CELF-4 Core Language Index). Deficits in synaptic integration in the auditory cortex are associated with oscillatory abnormalities in ASD as well as patient symptoms. Increased pre-stimulus activity in ASD likely demonstrates a fundamental signal-to-noise deficit in individuals with ASD, with elevations in oscillatory activity suggesting an inability to maintain an appropriate ‘neural tone’ and an inability to rapidly return to a resting state prior to the next stimulus.
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6. Ghanbari Y, Bloy L, Christopher Edgar J, Blaskey L, Verma R, Roberts TP. {{Joint Analysis of Band-Specific Functional Connectivity and Signal Complexity in Autism}}. {J Autism Dev Disord}. 2013.
Examination of resting state brain activity using electrophysiological measures like complexity as well as functional connectivity is of growing interest in the study of autism spectrum disorders (ASD). The present paper jointly examined complexity and connectivity to obtain a more detailed characterization of resting state brain activity in ASD. Multi-scale entropy was computed to quantify the signal complexity, and synchronization likelihood was used to evaluate functional connectivity (FC), with node strength values providing a sensor-level measure of connectivity to facilitate comparisons with complexity. Sensor level analysis of complexity and connectivity was performed at different frequency bands computed from resting state MEG from 26 children with ASD and 22 typically developing controls (TD). Analyses revealed band-specific group differences in each measure that agreed with other functional studies in fMRI and EEG: higher complexity in TD than ASD, in frontal regions in the delta band and occipital-parietal regions in the alpha band, and lower complexity in TD than in ASD in delta (parietal regions), theta (central and temporal regions) and gamma (frontal-central boundary regions); increased short-range connectivity in ASD in the frontal lobe in the delta band and long-range connectivity in the temporal, parietal and occipital lobes in the alpha band. Finally, and perhaps most strikingly, group differences between ASD and TD in complexity and FC appear spatially complementary, such that where FC was elevated in ASD, complexity was reduced (and vice versa). The correlation of regional average complexity and connectivity node strength with symptom severity scores of ASD subjects supported the overall complementarity (with opposing sign) of connectivity and complexity measures, pointing to either diminished connectivity leading to elevated entropy due to poor inhibitory regulation or chaotic signals prohibiting effective measure of connectivity.
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7. Keehn B, Wagner JB, Tager-Flusberg H, Nelson CA. {{Functional connectivity in the first year of life in infants at-risk for autism: a preliminary near-infrared spectroscopy study}}. {Front Hum Neurosci}. 2013; 7: 444.
Background: Autism spectrum disorder (ASD) has been called a « developmental disconnection syndrome, » however the majority of the research examining connectivity in ASD has been conducted exclusively with older children and adults. Yet, prior ASD research suggests that perturbations in neurodevelopmental trajectories begin as early as the first year of life. Prospective longitudinal studies of infants at risk for ASD may provide a window into the emergence of these aberrant patterns of connectivity. The current study employed functional connectivity near-infrared spectroscopy (NIRS) in order to examine the development of intra- and inter-hemispheric functional connectivity in high- and low-risk infants across the first year of life. Methods: NIRS data were collected from 27 infants at high risk for autism (HRA) and 37 low-risk comparison (LRC) infants who contributed a total of 116 data sets at 3-, 6-, 9-, and 12-months. At each time point, HRA and LRC groups were matched on age, sex, head circumference, and Mullen Scales of Early Learning scores. Regions of interest (ROI) were selected from anterior and posterior locations of each hemisphere. The average time course for each ROI was calculated and correlations for each ROI pair were computed. Differences in functional connectivity were examined in a cross-sectional manner. Results: At 3-months, HRA infants showed increased overall functional connectivity compared to LRC infants. This was the result of increased connectivity for intra- and inter-hemispheric ROI pairs. No significant differences were found between HRA and LRC infants at 6- and 9-months. However, by 12-months, HRA infants showed decreased connectivity relative to LRC infants. Conclusions: Our preliminary results suggest that atypical functional connectivity may exist within the first year of life in HRA infants, providing support to the growing body of evidence that aberrant patterns of connectivity may be a potential endophenotype for ASD.
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8. Lin CS, Chang SH, Liou WY, Tsai YS. {{The development of a multimedia online language assessment tool for young children with autism}}. {Res Dev Disabil}. 2013; 34(10): 3553-65.
This study aimed to provide early childhood special education professionals with a standardized and comprehensive language assessment tool for the early identification of language learning characteristics (e.g., hyperlexia) of young children with autism. In this study, we used computer technology to develop a multi-media online language assessment tool that presents auditory or visual stimuli. This online comprehensive language assessment consists of six subtests: decoding, homographs, auditory vocabulary comprehension, visual vocabulary comprehension, auditory sentence comprehension, and visual sentence comprehension. Three hundred typically developing children and 35 children with autism from Tao-Yuan County in Taiwan aged 4-6 participated in this study. The Cronbach alpha values of the six subtests ranged from .64 to .97. The variance explained by the six subtests ranged from 14% to 56%, the current validity of each subtest with the Peabody Picture Vocabulary Test-Revised ranged from .21 to .45, and the predictive validity of each subtest with WISC-III ranged from .47 to .75. This assessment tool was also found to be able to accurately differentiate children with autism up to 92%. These results indicate that this assessment tool has both adequate reliability and validity. Additionally, 35 children with autism have completed the entire assessment in this study without exhibiting any extremely troubling behaviors. However, future research is needed to increase the sample size of both typically developing children and young children with autism and to overcome the technical challenges associated with internet issues.
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9. Masri AT, Al Suluh N, Nasir R. {{Diagnostic delay of autism in Jordan: review of 84 cases}}. {Libyan J Med}. 2013; 8: 21725.
10. Pugliese CE, White SW. {{Brief Report: Problem Solving Therapy in College Students with Autism Spectrum Disorders: Feasibility and Preliminary Efficacy}}. {J Autism Dev Disord}. 2013.
Students with autism spectrum disorder (ASD), though academically capable, can have difficulty succeeding in college. Evidence-based intervention to promote effective problem solving may improve quality of life, as well as success and satisfaction in college. This study adapted and piloted a group-based cognitive-behavioral intervention program, Problem Solving Skills: 101 (PSS: 101), to teach effective problem solving ability in college students with ASD. Therapists met all treatment integrity objectives across sessions, four of the five participants completed at least eight of the nine sessions, and between-session assignments were generally completed (83 % completion rate), indicating a high level of treatment adherence. Two participants demonstrated reliable improvement post-intervention in problem solving ability and subjective distress. Further evaluation to assess efficacy of the intervention is warranted.
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11. Ramos M, Boada L, Moreno C, Llorente C, Romo J, Parellada M. {{Attitude and risk of substance use in adolescents diagnosed with Asperger syndrome}}. {Drug Alcohol Depend}. 2013.
BACKGROUND: Adolescence is a stage of development with increased risk of drug use. Individual personality traits are among those factors that influence the onset of substance use in adolescence and its psychiatric comorbidity. Little research has been done on the comorbidity between substance abuse risk and Asperger syndrome, and none specifically in adolescence. The objective of this study is to assess the risk of drug use by adolescents with Asperger syndrome and compare it with that risk in control subjects. A secondary objective was to analyze the personality factors that may be associated with substance use in the same two groups. METHODS: We used three self-administered questionnaires, one for drug risk assessment (FRIDA) and the other two for personality trait assessment (MACI and SSS-V). RESULTS: Adolescents diagnosed with Asperger syndrome are at less risk for drug use derived from family and access to drugs factors. Subjects with Asperger syndrome did score higher on introversive, inhibited, doleful, and borderline tendency prototypes than healthy controls, and scored lower on all sensation-seeking traits. Being male, a diagnosis of Asperger syndrome, and unruly, introversive, and sensation-seeking traits were all independently associated with the risk of drug abuse. CONCLUSIONS: Both identified personality factors and other variables associated with the Asperger syndrome contribute to the low risk of drug abuse observed in this population. Exploring protective factors for drug use in these subjects may prove useful for interventions with adolescents at risk for consumption.
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12. Webb SJ, Bernier R, Henderson HA, Johnson MH, Jones EJ, Lerner MD, McPartland JC, Nelson CA, Rojas DC, Townsend J, Westerfield M. {{Guidelines and Best Practices for Electrophysiological Data Collection, Analysis and Reporting in Autism}}. {J Autism Dev Disord}. 2013.
The EEG reflects the activation of large populations of neurons that act in synchrony and propagate to the scalp surface. This activity reflects both the brain’s background electrical activity and when the brain is being challenged by a task. Despite strong theoretical and methodological arguments for the use of EEG in understanding the neural correlates of autism, the practice of collecting, processing and evaluating EEG data is complex. Scientists should take into consideration both the nature of development in autism given the life-long, pervasive course of the disorder and the disability of altered or atypical social, communicative, and motor behaviors, all of which require accommodations to traditional EEG environments and paradigms. This paper presents guidelines for the recording, analyzing, and interpreting of EEG data with participants with autism. The goal is to articulate a set of scientific standards as well as methodological considerations that will increase the general field’s understanding of EEG methods, provide support for collaborative projects, and contribute to the evaluation of results and conclusions.
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13. Wong HS, Huertas-Ceballos A, Cowan FM, Modi N. {{Evaluation of Early Childhood Social-Communication Difficulties in Children Born Preterm Using the Quantitative Checklist for Autism in Toddlers}}. {J Pediatr}. 2013.
OBJECTIVES: To characterize early childhood social-communication skills and autistic traits in children born very preterm using the Quantitative Checklist for Autism in Toddlers (Q-CHAT) and explore neonatal and sociodemographic factors associated with Q-CHAT scores. STUDY DESIGN: Parents of children born before 30 weeks gestation and enrolled in a study evaluating routinely collected neurodevelopmental data between the post-menstrual ages of 20 and 28 months were invited to complete the Q-CHAT questionnaire. Children with severe neurosensory disabilities and cerebral palsy were excluded. Participants received neurodevelopmental assessments using the Bayley Scales of Infant and Toddler Development, 3rdedition (Bayley-III). Q-CHAT scores of this preterm cohort were compared with published general population scores. The association between Bayley-III cognitive and language scores and neonatal and sociodemographic factors with Q-CHAT scores were examined. RESULTS: Q-CHAT questionnaires were completed from 141 participants. At a mean post-menstrual age of 24 months, the Q-CHAT scores of the preterm cohort (mean 33.7, SD 8.3) were significantly higher than published general population scores (mean 26.7; SD 7.8), indicating greater social-communication difficulty and autistic behavior. Preterm children received higher scores, particularly in the categories of restricted, repetitive, stereotyped behavior, communication, and sensory abnormalities. Lower Bayley-III language scores and non-white ethnicity were associated with higher Q-CHAT scores. CONCLUSIONS: Preterm children display greater social-communication difficulty and autistic behavior than the general population in early childhood as assessed by the Q-CHAT. The implications for longer-term outcome will be important to assess.
