1. Bohm HV, Stewart MG, Healy AM. {{On the Autistic Spectrum Disorder concordance rates of twins and non-twin siblings}}. {Med Hypotheses};2013 (Aug 29)
Using the Interactive Autism Network Research Database, the Autistic Spectrum Disorder concordance rates for twins and non-twin siblings were calculated. For males, females and both genders together, the concordance rate for dizygotic twins is approximately twice that of non-twin siblings. We also determined that the concordance rate for non-twin siblings decreases as the interval between pregnancies increases. Our results appear to indicate that the uterine environment may contribute to autism concordance rates.
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2. Davis JM, Keeney JG, Sikela JM, Hepburn S. {{Mode of genetic inheritance modifies the association of head circumference and autism-related symptoms: a cross-sectional study}}. {PLoS One};2013;8(9):e74940.
BACKGROUND: Frequently individuals with autism spectrum disorder (ASD) have been noted with a larger head circumference (HC) than their typical developing peers. Biologic hypotheses suggest that an overly rapid brain growth leads to the core symptoms of ASD by impairing connectivity. Literature is divided however where deleterious, protective and null associations of HC with ASD symptoms in individuals with ASD have been found. METHOD: Individuals (n = 1,416) from the Autism Genetic Resource Exchange with ASD were examined for associations of HC with ASD like symptoms. Mixed models controlling for sex, age, race/ethnicity, simplex/multiplex status and accounting for correlations between siblings were used. Interactions by simplex/multiplex were explored. Adjustments for height in a sub-population with available data were explored as well. RESULTS: A Significant interaction term (p = 0.03) suggested that the effect of HC was dependent on whether the individual was simplex or multiplex. In simplex individuals at mean age (8.9 years) 1 cm increase in head circumference was associated with a 24% increase in the odds of a high social diagnostic score from the Autism Diagnostic Interview – Revised (odds ratio = 1.24, p = 0.01). There was no association in multiplex individuals. Additionally, individuals classified with a non-verbal IQ <70 were 90% simplex and had a significantly increased head circumference (0.7 cm p = 0.03) relative to a mid-range non-verbal IQ group. Interestingly, children classified with a >110 non-verbal IQ also had an increased HC (0.4 cm p = 0.04), relative to a mid-range non-verbal IQ group, and were 90% multiplex. HC effects do not appear to be confounded by height, however, larger samples with height information are needed. CONCLUSION: The potential link between brain growth and autism like symptoms is complex and could depend on specific etiologies. Further investigations accounting for a likely mode of inheritance will help identify an ASD subtype related to HC.
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3. Devine DP. {{Self-injurious behaviour in autistic children: a neuro-developmental theory of social and environmental isolation}}. {Psychopharmacology (Berl)};2013 (Sep 21)
RATIONALE: Self-injurious behaviour is not one of the three core symptoms that define autism. However, children on the autism spectrum appear to be particularly vulnerable. Afflicted children typically slap their faces, punch or bang their heads, and bite or pinch themselves. These behaviours can be extremely destructive, and they interfere with normal social and educational activities. However, the neurobiological mechanisms that confer vulnerability in children with autism have not been adequately described. OBJECTIVES: This review explores behavioural and neurobiological characteristics of children with autism that may be relevant for an increased understanding of their vulnerability for self-injurious behaviour. METHODS: Behavioural characteristics that are co-morbid for self-injurious behaviour in children with autism are examined. In addition, the contributions of social and environmental deprivation in self-injurious institutionalized orphans, isolated rhesus macaques, and additional animal models are reviewed. RESULTS: There is extensive evidence that social and environmental deprivation promotes self-injurious behaviour in both humans (including children with autism) and animal models. Moreover, there are multiple lines of convergent neuroanatomical, neurophysiological, and neurochemical data that draw parallels between self-injurious children with autism and environmentally deprived humans and animals. CONCLUSIONS: A hypothesis is presented that describes how the core symptoms of autism make these children particularly vulnerable for self-injurious behaviour. Relevant neurodevelopmental pathology is described in cortical, limbic, and basal ganglia brain regions, and additional research is suggested.
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4. Fournier KA, Amano S, Radonovich KJ, Bleser TM, Hass CJ. {{Decreased dynamical complexity during quiet stance in children with Autism Spectrum Disorders}}. {Gait Posture};2013 (Aug 23)
BACKGROUND: Postural control deficits in individuals with Autism Spectrum Disorders (ASD) are widely acknowledged; however, the underlying biomechanical features of these deficits remain unknown. Nonlinear analyses provide insight into the nature of how movement is controlled and have the potential to provide new insight into the postural control abnormalities associated with ASD. The purpose of this study was to further investigate postural control deficits in children with ASD through linear and nonlinear analyses of center of pressure (COP) data. METHODS: We evaluated COP data during quiet standing for 16 children with ASD and 17 age-matched typically developing (TD) children. The magnitude of COP fluctuations (COP ranges, velocity, and sway area) and complexity of postural control dynamics, quantified by multiscale entropy (MSE), were compared across groups. RESULTS: Children with ASD displayed larger fluctuations in their COP data, observed in COP ranges (95.5% mediolaterally and 46.9% anteroposteriorly, p<0.05 respectively) and COP sway area (885%, p<0.05). Children with ASD also displayed less complexity in their COP data, observed in the MSE complexity index (CI) (32.4% mediolaterally and 35.7% anteroposteriorly, p<0.05 respectively). CONCLUSIONS: The present study successfully revealed that children with ASD have more repetitive patterns in their COP data, indicating a less complex control of posture, on multiple time scales, during quiet stance. These findings suggest a more regular or restricted control of posture and may be an initial step in linking postural instability to stereotypic behavior and the neurobiology of ASD.
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5. Kenworthy L, Wallace GL, Birn R, Milleville SC, Case LK, Bandettini PA, Martin A. {{Aberrant neural mediation of verbal fluency in autism spectrum disorders}}. {Brain Cogn};2013 (Sep 18);83(2):218-226.
OBJECTIVE: Contrasts of verbal fluency and automatic speech provide an opportunity to evaluate the neural underpinnings of generativity and flexibility in autism spectrum disorders (ASD). METHOD: We used functional magnetic resonance imaging (fMRI) to contrast brain activity in high functioning ASD (n=17, mean verbal IQ=117) and neurotypical (NT; n=20, mean verbal IQ=112) adolescent and young adult males (12-23years). Participants responded to three word generation conditions: automatic speech (reciting months), category fluency, and letter fluency. RESULTS: Our paradigm closely mirrored behavioral fluency tasks by requiring overt, free recall word generation while controlling for differences in verbal output between the groups and systematically increasing the task demand. The ASD group showed reduced neural response compared to the NT participants during fluency tasks in multiple regions of left anterior and posterior cortices, and sub-cortical structures. Six of these regions fell in cortico-striatal circuits previously linked to repetitive behaviors (Langen, Durston, Kas, van Engeland, & Staal, 2011), and activity in two of them (putamen and thalamus) was negatively correlated with autism repetitive behavior symptoms in the ASD group. In addition, response in left inferior frontal gyrus was differentially modulated in the ASD, relative to the NT, group as a function of task demand. CONCLUSIONS: These data indicate a specific, atypical brain response in ASD to demanding generativity tasks that may have relevance to repetitive behavior symptoms in ASD as well as to difficulties generating original verbal responses.
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6. Kuwabara H, Yamasue H, Koike S, Inoue H, Kawakubo Y, Kuroda M, Takano Y, Iwashiro N, Natsubori T, Aoki Y, Kano Y, Kasai K. {{Altered Metabolites in the Plasma of Autism Spectrum Disorder: A Capillary Electrophoresis Time-of-Flight Mass Spectroscopy Study}}. {PLoS One};2013;8(9):e73814.
Clinical diagnosis and severity of autism spectrum disorders (ASD) are determined by trained clinicians based on clinical evaluations of observed behaviors. As such, this approach is inevitably dependent on the expertise and subjective assessment of those administering the clinical evaluations. There is a need to identify objective biological markers associated with diagnosis or clinical severity of the disorder. To identify novel candidate metabolites as potential biomarkers for ASD, the current study applied capillary electrophoresis time-of-flight mass spectroscopy (CE-TOFMS) for high-throughput profiling of metabolite levels in the plasma of 25 psychotropic-naive adult males with high-functioning ASD and 28 age-matched typically-developed control subjects. Ten ASD participants and ten age-matched controls were assigned in the first exploration set, while 15 ASD participants and 18 controls were included in the second replication set. By CE-TOFMS analysis, a total of 143 metabolites were detected in the plasma of the first set. Of these, 17 metabolites showed significantly different relative areas between the ASD participants and the controls (p<0.05). Of the 17 metabolites, we consistently found that the ASD participants had significantly high plasma levels of arginine (p = 0.024) and taurine (p = 0.018), and significantly low levels of 5-oxoproline (p<0.001) and lactic acid (p = 0.031) compared with the controls in the second sample set. Further confirmatory analysis using quantification of absolute metabolite concentrations supported the robustness of high arginine (p = 0.001) and low lactic acid (p = 0.003) in the combined sample (n = 53). The present study identified deviated plasma metabolite levels associated with oxidative stress and mitochondrial dysfunction in individuals with ASD.
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7. Maxwell CR, Parish-Morris J, Hsin O, Bush JC, Schultz RT. {{The broad autism phenotype predicts child functioning in autism spectrum disorders}}. {J Neurodev Disord};2013 (Sep 22);5(1):25.
BACKGROUND: Broad autism phenotype (BAP) is a milder expression of the social and communication impairments seen in autism spectrum disorders (ASD). While prior studies characterized the BAP in unaffected family members of probands with ASD, the relationship between parental BAP traits and proband symptomatology remains poorly understood. This study utilizes the Broad Autism Phenotype Questionnaire (BAPQ) in parents and the Social Responsiveness Scale (SRS) in children to examine this connection. We hypothesized that in families affected by ASD, elevated maternal and paternal BAPQ scores would correlate with greater autism symptomatology in diagnosed children. In an extension of prior research, we also explored this relationship in families with typically developing children (TDC). METHODS: Two hundred and forty-five children with ASD, 129 TDC and all parents were recruited as part of a larger study investigating relationships between genes, brain and behavior. The Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule (ADOS) and expert clinical judgment confirmed ASD diagnoses in children. SRS was collected for all children. Parents completed a self-report BAPQ and an informant report BAPQ for their spouse; an average of self-report and informant report for each parent was used in all analyses. RESULTS: Mothers and fathers of children with ASD had significantly higher rates of BAP traits as compared to parents of TDC. Maternal and paternal BAPQ total scores were not correlated with child IQ in either group. In the ASD group, 10% of mothers and 21% of fathers scored above the established BAP threshold compared to 4% of TDC parents. Crude regression analyses showed that maternal and paternal BAPQ total scores accounted for significant variance in child SRS scores in both ASD (17.1%) and TDC (19.8%) families. CONCLUSIONS: Our results suggest that broad autism symptomatology in parents is moderately associated with their child’s autism symptomatology. This result extended to TDC families, suggesting that the BAPQ and SRS capture subtle, subclinical social variation in both children and adults. These findings could help define multi-generational social impairments in future phenotypic and genetic studies.
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8. Mukherjee S, Rupani K, Dave M, Subramanyam A, Shah H, Kamath R. {{Evaluation of Effectiveness of Integrated Intervention in Autistic Children}}. {Indian J Pediatr};2013 (Sep 21)
OBJECTIVES: To assess the effectiveness of integrated therapy over the past 3 y on the recipient autistic children and its correlation with the following variables – age at admission, duration of therapy given and initial severity of symptoms. METHODS: The index study was a retrospective study with 18 autistic children as subjects; the maximum duration of intervention was 3 y. The integrated approach consisted of special education using principles of applied behavior analysis, occupational and speech therapy. The progress records, the occupational therapy and the speech therapy progress reports were tabulated as data. The Childhood Autism Rating Scale (Schopler, Reichler and Renner, 1986) was used for evaluation of severity of symptoms at admission and in present day. The data was then compared and analyzed. RESULTS: The present study showed significant positive results. Only few domains requiring very high integrated cognitive and sensorimotor functioning showed non-significant results. Age at intervention correlated negatively and, duration of therapy given and initial severity of symptoms correlated positively with effectiveness of therapy. CONCLUSIONS: Continuous feedback and modification of the therapy is required to maintain performance and develop target interventions for problematic areas identified. Longitudinal as well as comparative studies are required to better understand the benefits of integrated approach.
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9. O’Keefe N, Lindell AK. {{Reduced interhemispheric interaction in non-autistic individuals with normal but high levels of autism traits}}. {Brain Cogn};2013 (Sep 17);83(2):183-189.
People with autism spectrum disorder (ASD) show superior performance for tasks requiring detail-focused processing. Atypical neural connectivity and reduced interhemispheric communication are posited to underlie this cognitive advantage. Given recent conceptualization of autism as a continuum, we sought to investigate whether people with normal but high levels of autism like traits (AQ) also exhibit reduced hemispheric interaction. Sixty right-handed participants completed the AQ questionnaire (Baron-Cohen, Wheelwright, Skinner, Martin, & Clubley, 2001) and a lateralised letter matching task that assessed unilateral and bilateral performance in response to simple (physical) and complex (identity) matches. Whereas people with low self-rated AQ scores showed a bilateral advantage for the more complex task, indicating normal interhemispheric interaction, people in the high AQ group failed to show a bilateral gain for the computationally demanding stimuli. This finding of disrupted interhemispheric interaction converges with a dimensional conceptualisation of ASD, suggesting that the structural anomalies of ASD extend to non-autistic individuals with high levels of autism traits.
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10. Roberts TP, Lanza MR, Dell J, Qasmieh S, Hines K, Blaskey L, Zarnow DM, Levy SE, Christopher Edgar J, Berman JI. {{Maturational differences in thalamocortical white matter microstructure and auditory evoked response latencies in autism spectrum disorders}}. {Brain Res};2013 (Sep 18)
White matter diffusion anisotropy in the acoustic radiations was characterized as a function of development in autistic and typically developing children. Auditory-evoked neuromagnetic fields were also recorded from the same individuals and the latency of the left and right middle latency superior temporal gyrus auditory approximately 50ms response (M50)1 measured. Group differences in structural and functional auditory measures were examined, as were group differences in associations between white matter pathways, M50 latency, and age. Acoustic radiation white matter fractional anisotropy did not differ between groups. Individuals with autism displayed a significant M50 latency delay. Only in typically developing controls, white matter fractional anisotropy increased with age and increased white matter anisotropy was associated with earlier M50 responses. M50 latency, however, decreased with age in both groups. Present findings thus indicate that although there is loss of a relationship between white matter structure and auditory cortex function in autism spectrum disorders, and although there are delayed auditory responses in individuals with autism than with age-matched controls, M50 latency nevertheless decreases as a function of age in autism, parallel to the observation in typically developing controls (although with an overall latency delay). To understand auditory latency delays in autism and changes in auditory responses as a function of age in controls and autism, studies examining white matter as well as other factors that influence auditory latency, such as synaptic transmission, are of interest.
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11. Stahmer AC, Brookman-Frazee L, Lee E, Searcy K, Reed S. {{Parent and Multidisciplinary Provider Perspectives on Earliest Intervention for Children at Risk for Autism Spectrum Disorders}}. {Infants Young Child};2011 (Oct);24(4):344-363.
Early identification and treatment of Autism Spectrum Disorder (ASD) in children younger than age 3 years is becoming an increasingly common area of concern and study. Research suggests that systematic, early intervention can significantly improve outcomes and reduce the cost of caring for children with ASD through the lifespan. Therefore, it is imperative that evidence-based practices (EBPs) for this young age group are translated effectively into community settings. One method of promoting EBPs and developing capacity for implementation is active collaboration between researchers and community stakeholders. This requires a precise understanding of the perspectives of stakeholders regarding the benefits and barriers of specific practices and early intervention in general. In the current study, we gathered feedback from families and a multidisciplinary group of community providers regarding early intervention values for infants/toddlers at risk for ASD and their families through focus groups. The opinions and values of the community sample were examined using mixed qualitative and quantitative methods to facilitate efforts to build long-term capacity for implementing efficacious ASD intervention for children younger than 3 years. Results indicated that, the values of community providers and parents were highly similar and were aligned with EBP strategies. Recommendations for translating EBPs for this population into community settings are discussed.
12. Timberlake MT, Leutz WN, Warfield ME, Chiri G. {{« In the Driver’s Seat »: Parent Perceptions of Choice in a Participant-Directed Medicaid Waiver Program for Young Children with Autism}}. {J Autism Dev Disord};2013 (Sep 22)
This study investigated families’ experience of choice within a participant-directed Medicaid waiver program for young children with autism. Fourteen parents or grandparents participated in in-depth interviews about their experience of choosing personnel, directing in-home services, and managing the $25,000 annual allocation. Key findings included families’ preference to hire providers with whom they have a prior relationship, parent empowerment and differences of opinion about parents as teachers. Professionals implementing participant directed service models could benefit from understanding the strong value parents’ placed on the personalities and interpersonal skills of providers. Parents’ descriptions of directing rather than merely accepting autism services revealed increased confidence in their ability to choose and manage the multiple components of their children’s HCBS autism waiver program.
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13. Werner S, Shulman C. {{Subjective well-being among family caregivers of individuals with developmental disabilities: The role of affiliate stigma and psychosocial moderating variables}}. {Res Dev Disabil};2013 (Sep 17);34(11):4103-4114.
Studies have shown that stigmatization is linked to lower quality of life; however, only scant research has examined the association between family caregivers’ internalization of stigma (affiliate stigma) and their subjective quality of life (subjective well-being, SWB). Furthermore, studies have rarely examined this association via comparison between caregivers of individuals with different developmental disabilities in addition to examining the influence of psychosocial protective factors. These were the aims of the current study. Family caregivers (N=176) of individuals with autism spectrum disorders (ASD), intellectual disabilities (ID), and physical disabilities (PD) completed a self-report structured questionnaire including scales measuring SWB, affiliate stigma, burden, positive meaning in caregiving, social support and self-esteem. Results showed that SWB of family caregivers was below the average normative level and especially low for caregivers of individuals with ASD. The strongest predictors of SWB were caregivers’ self-esteem, social support, positive meaning in caregiving, and affiliate stigma. Furthermore, an interaction was found between affiliate stigma and diagnosis, showing that among caregivers of individuals with ASD, greater levels of stigma were associated with lower ratings of SWB, whereas such an association was not found among caregivers of individuals with ID or PD. Findings from this study point to the importance of supporting caregivers across the life-span in order to decrease stigma, improve social support and self-esteem and improve SWB. Further, findings point to the need to respond differentially to the various developmental disabilities.
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14. Xu G, Jing J, Bowers K, Liu B, Bao W. {{Maternal Diabetes and the Risk of Autism Spectrum Disorders in the Offspring: A Systematic Review and Meta-Analysis}}. {J Autism Dev Disord};2013 (Sep 22)
We performed a systematic literature search regarding maternal diabetes before and during pregnancy and the risk of autism spectrum disorders (ASD) in the offspring. Of the 178 potentially relevant articles, 12 articles including three cohort studies and nine case-control studies were included in the meta-analysis. Both the meta-analyses of cohort studies and case-control studies showed significant associations. The pooled relative risk and 95 % confidence interval (CI) among cohort studies was 1.48 (1.25-1.75, p < 0.001). For case-control studies, the pooled odds ratio and 95 % CI was 1.72 (1.24-2.41, p = 0.001). No indication of significant heterogeneity across studies or publication bias was observed. In conclusion, maternal diabetes was significantly associated with a greater risk of ASD in the offspring.
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15. Young RL, Rodi ML. {{Redefining Autism Spectrum Disorder Using DSM-5: The Implications of the Proposed DSM-5 Criteria for Autism Spectrum Disorders}}. {J Autism Dev Disord};2013 (Sep 22)
A number of changes were made to pervasive developmental disorders (PDDs) in the recently released diagnostic and statistical manual of mental disorders (APA, Diagnostic and statistical manual of mental disorders, American Psychiatric Publishing, Arlington, VA, 2013). Of the 210 participants in the present study who met DSM-IV-TR criteria for a PDD [i.e., autistic disorder, Asperger’s disorder and pervasive developmental disorder-not otherwise specified (PDD-NOS)], only 57.1 % met DSM-5 criteria (specificity = 1.0) for autism spectrum disorder when criteria were applied concurrently during diagnostic assessment. High-functioning individuals (i.e., Asperger’s disorder and PDD-NOS) were less likely to meet DSM-5 criteria than those with autistic disorder. A failure to satisfy all three criteria in the social-communication domain was the most common reason for exclusion (39 %). The implications of these results are discussed.
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16. Youssef J, Singh K, Huntington N, Becker R, Kothare SV. {{Relationship of serum ferritin levels to sleep fragmentation and periodic limb movements of sleep on polysomnography in autism spectrum disorders}}. {Pediatr Neurol};2013 (Oct);49(4):274-278.
OBJECTIVE: Although children with autism spectrum disorders experience a range of sleep disturbances, exact mechanisms are not well-characterized. We investigated the association of serum-ferritin to sleep fragmentation and periodic limb movements of sleep using polysomnography in children with autism spectrum disorders. METHODS: We conducted a retrospective chart review of children with autism spectrum disorders followed from 1990 to 2010. Inclusion criteria were availability of polysomnography data and ferritin levels within 12 months of each other. The following variables on polysomnography characterized sleep fragmentation: increased arousal index, alpha intrusions, and reduced sleep efficiency. The data were compared with age- and gender-matched controls. RESULTS: Of 9791 children with autism spectrum disorders identified, 511 had a ferritin level, 377 had polysomnography data, and 53 had both ferritin and polysomnography data. As compared with the controls (86 ng/mL), the median ferritin level was 27 ng/mL in the study autism spectrum disorders population (53 patients) (P < 0.01), 27 ng/mL in autism spectrum disorder subjects with periodic limb movements of sleep (25 patients) (P = 0.01), and 24 ng/mL in autism spectrum disorders subjects with sleep fragmentation (21 patients) (P = 0.02). Within the autism spectrum disorders population, median ferritin levels were significantly lower in patients with poor sleep efficiency (7 ng/mL) versus those with normal sleep efficiency (29 ng/mL) (P = 0.01). The prevalence of periodic limb movements of sleep was 47% in autism spectrum disorders compared with 8% in controls (P < 0.01). CONCLUSION: Children with autism spectrum disorders had significantly lower ferritin levels compared with controls. In addition, they experience a higher prevalence of sleep fragmentation, obstructive sleep apnea, and periodic limb movements of sleep than children with ASD and no sleep complaints. Our preliminary observations, which have not been described before, need to be validated in multicenter prospective studies.
