Restricted Repetitive Behaviors Research Articles

Volumetric magnetic resonance and diffusion tensor imaging of C58/J mice: neural correlates of repetitive behavior.

Restricted, repetitive behavior (RRB) involves sequences of responding with little variability and no obvious function. RRB is diagnostic for autism spectrum disorder (ASD) and a significant feature in several neurodevelopmental disorders. Despite its clinical importance, relatively little is known about how RRB is mediated by broader neural circuits. In this study, we employed ultra-high field (17.6 Tesla) magnetic resonance imaging (MRI) to study the C58/J mouse model of RRB. We determined alterations in brain morphology and connectivity of C58/J mice and their relationship to repetitive motor behavior using structural MRI and diffusion tensor imaging (DTI). Compared to the genetically similar C57BL/6 control mouse strain, C58/J mice showed evidence of structural alterations in basal ganglia and cerebellar networks. In particular, C58/J mice exhibited reduced volumes of key cortical and basal ganglia regions that have been implicated in repetitive behavior, including motor cortex, striatum, globus pallidus, and subthalamic nucleus, as well as volume differences in the cerebellum. Moreover, DTI revealed differences in fractional anisotropy and axial diffusivity in cerebellar white matter of C58/J mice. Importantly, we found that RRB exhibited by C58/J mice was correlated with volume of the striatum, subthalamic nucleus, and crus II of the cerebellum. These regions are key nodes in circuits connecting the basal ganglia and cerebellum and our findings implicate their role in RRB, particularly the indirect pathway.

Behavioral characteristics of autism spectrum disorder in very preterm birth children

BackgroundLower gestational age may increase autism spectrum disorder (ASD) vulnerability; however, the incidence of ASD diagnosis through a direct assessment on every very preterm birth child on the population base remains unclear. Moreover, the behavioral characteristics of preterm birth ASD are unknown.MethodsEvery very preterm birth child (gestational age < 32 weeks; birth weight < 1500 g) who was discharged from neonatal intensive care units in Southern Taiwan and prospectively followed to 5 years of age was evaluated using the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R). The term birth (gestational age > 37 weeks) ASD children characterized by ADOS and ADI-R were group matched to the preterm birth ASD by age at examination for comparison. ADOS severity scores were calculated by the Mann–Whitney U test and ADI-R by multivariate analysis of variance and canonical discriminant analysis.ResultsTwo hundred forty-six (87%) of the 283 very preterm survivors were followed prospectively to 5 years of age. Nineteen (7.7%) of the 246 children fulfilled the diagnostic criteria of ASD. After excluding 1 patient with cerebral palsy and profound mental disability, 18 preterm ASD children were compared with 44 term birth ASD children. The two ASD groups were comparable for age at examination, gender, and intelligence quotient. The two groups showed comparable ADOS severity scores in social affect deficits, restricted repetitive behaviors, and total score, but had differences in qualitative abnormalities in reciprocal social interaction (Wilks lambda F value = 6.2, P < 0.001) of ADI-R. Compared to term birth ASD children, preterm birth ASD children exhibited worse nonverbal behaviors that regulate social interaction (OR 2.59, 95% CI 1.41–4.73, P = 0.002) but more favorable peer relationships (OR 0.58, 95% CI 0.38–0.90, P = 0.01) and socioemotional reciprocity (OR 0.55, 95% CI 0.33–0.92, P = 0.02). In contrast to the heterogeneous severity of social reciprocity in the term ASD group, the behavioral characteristics of the preterm ASD group showed a homogeneous reciprocal social interaction pattern.ConclusionsThe 5-year incidence rate of ASD was high in very preterm birth children. Preterm birth ASD exhibited a specific behavioral phenotype of reciprocal social interaction.

Social communication deficits and restricted repetitive behavior symptoms in Tourette syndrome.

Background: Autism spectrum disorders (ASD) have been found to occur more frequently in individuals with Tourette syndrome (TS) than in the general population. Similarities exist between ASD and TS clinically, which suggests a potential relationship between the two conditions.Purpose: The purpose of this study was to explore the occurrence of autism-related features in ASD and TS, focusing on areas of overlap and difference.Patients and methods: This study examined the nature and extent of autistic traits as measured by the Social Communication Questionnaire (SCQ) in a sample with a diagnosis of TS, a sample diagnosed to have ASD, and a normative general population sample.Results: The TS sample had significantly higher mean SCQ scores than the general population, but generally lower scores than the ASD sample. The group differences in mean SCQ scores between the TS and ASD sample were significant except in the domain of restricted repetitive behaviours (RRB).Conclusion: This suggests that ASD traits occur commonly in the TS population, with a significant overlap in certain clinical features. This was especially the case for complex movements or repetitive behaviours, which may represent either: i) a shared phenotype which is subclinical, ii) a phenocopy where some clinical symptoms mimic each other, or iii) a co-morbidity. Awareness of this association can be useful in identifying these symptoms as part of the comprehensive assessment of TS and addressing these to improve the overall clinical outcomes in these patients.

A Neuroanatomical Substrate Linking Perceptual Stability to Cognitive Rigidity in Autism.

Overly stable visual perception seen in individuals with autism spectrum disorder (ASD) is related to higher-order core symptoms of the condition. However, the neural basis by which these seemingly different symptoms are simultaneously observed in individuals with ASD remains unclear. Here, we aimed to identify such a neuroanatomical substrate linking perceptual stability to autistic cognitive rigidity, a part of core restricted, repetitive behaviors (RRBs). First, using a bistable visual perception test, we measured the perceptual stability of 22 high-functioning adults with ASD and 22 age-, IQ-, and sex-matched typically developing human individuals and confirmed overstable visual perception in autism. Next, using a spontaneous task-switching (TS) test, we showed that the individuals with ASD were more likely to repeat the same task voluntarily and spontaneously, and such rigid TS behavior was associated with the severity of their RRB symptoms. We then compared these perceptual and cognitive behaviors and found a significant correlation between them for individuals with ASD. Finally, we found that this behavioral link was supported by a smaller gray matter volume (GMV) of the posterior superior parietal lobule (pSPL) in individuals with ASD. Moreover, this smaller GMV in the pSPL was also associated with the RRB symptoms and replicated in two independent datasets. Our findings suggest that the pSPL could be one of the neuroanatomical mediators of cognitive and perceptual inflexibility in autism, which could help a unified biological understanding of the mechanisms underpinning diverse symptoms of this developmental disorder.SIGNIFICANCE STATEMENT Behavioral studies show perceptual overstability in autism spectrum disorder (ASD). However, the neural mechanisms by which such sensory symptoms can coexist and often correlate with seemingly separate core symptoms remain unknown. Here, we have identified such a key neuroanatomical substrate. We have revealed that overstable sensory perception of individuals with ASD is linked with their cognitive rigidity, a part of core restricted, repetitive behavior symptoms, and such a behavioral link is underpinned by a smaller gray matter volume in the posterior superior parietal lobule in autism. These findings uncover a key neuroanatomical mediator of autistic perceptual and cognitive inflexibility and would ignite future studies on how the core symptoms of ASD interact with its unique sensory perception.

Differences in the expression of restricted repetitive behaviors in female and male BTBR T + tf/J mice

Autism spectrum disorder (ASD) is characterized by the expression of restricted repetitive behaviors (RRBs) and impairments in social recognition and communication. Epidemiological studies demonstrate males are three times more likely than females to be affected. Although this is the case, more recent studies suggest females may be underrepresented in these numbers due to standard clinical measures of RRBs and social behaviors. In addition, many studies examining mouse models of ASD exclude females due to the sex disparity in diagnoses. The present study examined how female and male BTBR T + Itpr3tf /J (BTBR) compare to control C57BL/6J mice on tests of RRBs (probabilistic reversal learning, repetitive grooming, spontaneous alternation, and marble burying) and social behaviors (three chambered social approach task). Utilizing a spatial reversal learning test with 80/20 probabilistic feedback, in which ASD individuals have exhibited deficits, we find that female BTBR mice do not show the same impairment found in male BTBR mice. Interestingly, control female C57BL/6J mice required more trials to reach criterion. Female BTBR mice expressed comparable rates of repetitive grooming, marble burying and spontaneous alternation compared to female C57BL/6J mice. Male BTBR mice expressed higher rates of grooming behavior and locomotor activity compared to male C57BL/6J mice, as found in previous studies. Similarly, male BTBR mice showed a reduction in both measures of social approach compared to controls. Both male and female BTBR mice showed a reduction in sniff time for the stranger mouse compared to controls. Together these findings demonstrate how female BTBR mice do not display the RRB profile expressed by male BTBR mice. Testing of repetitive behaviors in ASD needs to better reflect the sex differences in how RRBs manifest in females compared to their extensively researched male counterparts.

Sex Differences in Autism Spectrum Disorders Across the Lifespan

This review aimed to examine contemporary findings on sex-related differences in autism spectrum disorder from pre-school to adulthood. By exploring the literature within developmental time points, it is possible to consider emerging lifespan patterns and determine consistency of results without the impact of developmental change. Findings continue to be varied due to numerous methodological differences across studies. However, some results are more consistent than others. For instance, while there is no evidence for a sex difference in cognition in early childhood, there may be executive functioning differences in adolescence/adulthood. Further males exhibit more and different restricted repetitive behaviours, while females have more motivation toward friendships and compensatory behaviours. The results reviewed provide emerging evidence for a female behaviour phenotype of ASD. However, future research should include a non-autistic comparison sample and consider the impact of sample characterisation (e.g. age range and genotype).

변별자극을 통한 자기관리가 자폐스펙트럼장애 학생의 제한된 반복행동과 자기통제에 미치는 효과

The purpose of this study was to investigate the effect of self-management strategy utilizing discrimination procedures on restrictive repetitive behavior and self-control of students with autism spectrum disorder. The research was designed in use of mixed form of multiple baseline design across settings and changing condition design. The restrictive repetitive behavior, A dependent variable of this study, the repetitive one that is inadvertently emitted ahead of mustering control power to avoid the same, then returning in sticking to the same. The study purports to exhibit both reduction of problem behavior and increase of alternative behavior, then toward generalization in two ways. Target behaviors are defined as compulsive behaviors that would burst out, e.g. bolting just before they are supported to walk forward as an alternative behavior of bolting. The study was conducted in a sequence of preliminary interviews, observation, baseline, intervention, maintenance, and generalization phases. Self-control, which showed low incidence in the baseline, showed rapid behavior change after intervention, 100% increase in maintenance, and effective generalization as vice versa with restrictive repetitive behaviors. which showed low incidence in the baseline, showed rapid behavior change after intervention, 100% increase in maintenance, and effective generalization. In conclusion, self-management through discrimination procedures turned out to have a significant effect on decreasing restrictive repetitive behavior and on increasing self-control of students with autism spectrum disorder throughout intervention, maintenance and generalization phases.

Impaired development of neocortical circuits contributes to the neurological alterations in DYRK1A haploinsufficiency syndrome

Autism spectrum disorders are early onset neurodevelopmental disorders characterized by deficits in social communication and restricted repetitive behaviors, yet they are quite heterogeneous in terms of their genetic basis and phenotypic manifestations. Recently, de novo pathogenic mutations in DYRK1A, a chromosome 21 gene associated to neuropathological traits of Down syndrome, have been identified in patients presenting a recognizable syndrome included in the autism spectrum. These mutations produce DYRK1A kinases with partial or complete absence of the catalytic domain, or they represent missense mutations located within this domain. Here, we undertook an extensive biochemical characterization of the DYRK1A missense mutations reported to date and show that most of them, but not all, result in enzymatically dead DYRK1A proteins. We also show that haploinsufficient Dyrk1a+/− mutant mice mirror the neurological traits associated with the human pathology, such as defective social interactions, stereotypic behaviors and epileptic activity. These mutant mice present altered proportions of excitatory and inhibitory neocortical neurons and synapses. Moreover, we provide evidence that alterations in the production of cortical excitatory neurons are contributing to these defects. Indeed, by the end of the neurogenic period, the expression of developmental regulated genes involved in neuron differentiation and/or activity is altered. Therefore, our data indicate that altered neocortical neurogenesis could critically affect the formation of cortical circuits, thereby contributing to the neuropathological changes in DYRK1A haploinsufficiency syndrome.

Perception and convenience of caring for children with autism spectrum disorder among family medicine residents in Riyadh 2018.

Background:Autism spectrum disorder (ASD) is a group of childhood pervasive neurodevelopmental disorders characterized predominantly by persistent moderate to severe impairment in social skills, communication, and associated with restricted repetitive or stereotyped behaviors. Early diagnosis of this disorder is paramount, which then allows for a timely intervention to facilitate a positive prognosis. To the best of our knowledge, there is no study that has investigated the perception of ASD among family medicine residents in Saudi Arabia.Objective:To determine the level of awareness of childhood autism among family medicine residents in Riyadh.Settings and Design:A cross-sectional study was conducted in nine teaching primary healthcare centers in Riyadh.Materials and Methods:The questionnaire was adopted from Unigwe et al. study and distributed to 344 available physicians, of which 277 were received back completed.Results:Only 28 physicians (10.1%) answered positively if they had previously attended any ASD workshops or conferences. In addition, only 29 participants (10.5%) correctly answered 50% or more questions. The question that yielded the lowest scoring was “Recognizing the signs and symptoms of autism in individuals with good language and no apparent intellectual difficulties”, while the question with the highest scoring was “Identifying stress in the parents and carers of my patients with autism.” The regression analysis showed no association between the scores and the physicians’ characteristics.Conclusions:The results show a low awareness level and moderate to low level of confidence in the physicians ability to recognize, identify, or communicate in regards to ASD. We recommend integrating lectures and clinical exposure of ASD to the residency training program curriculum.

Functional connectivity in ASD: Atypical pathways in brain networks supporting action observation and joint attention

Autism Spectrum Disorder (ASD) is a developmental disorder characterized by impaired social communication, including attending to and interpreting social cues, initiating and responding to joint attention, and engaging in abstract social cognitive reasoning. Current studies emphasize a underconnectivity in ASD, particularly for brain systems that support abstract social reasoning and introspective thought. Here, we evaluate intrinsic connectivity in children with ASD, targeting brain systems that support the developmental precursors to social reasoning, namely perception of social cues and joint attention. Using resting state fMRI made available through the Autism Brain Imaging Data Exchange (ABIDE), we compute functional connectivity within and between nodes in the action observation, attention and social cognitive networks in children and adolescents with ASD. We also compare connectivity strength to observational assessments that explicitly evaluate severity of ASD on two distinct subdomains using the ADOS-Revised schedule: social affective (SA) and restricted, repetitive behaviors (RRB). Compared to age-matched controls, children with ASD have decreased functional connectivity in a number of connections in the action observation network, particularly in the lateral occipital cortex (LOTC) and fusiform gyrus (FG). Distinct patterns of connections were also correlated with symptom severity on the two subdomains of the ADOS. ADOS-SA severity most strongly correlated with connectivity to the left TPJ, while ADOS-RRB severity correlated with connectivity to the dMPFC. We conclude that atypical connectivity in the action observation system may underlie some of the more complex deficits in social cognitive systems in ASD.

5.20 Efficacy of Transcranial Near-Infrared Light Treatment in ASD: Interim Analysis of an Open-Label Proof of Concept Study of a Novel Approach

ASD is characterized by variable presentation of difficulties with socialization, communication, and restrictive/repetitive behaviors (RRB), for which no established pharmacological treatment exists. Transcranial Laser Emitting Diode (LED) Therapy (TLT) is a noninvasive intervention with near-infrared light to forebrain. It is absorbed by cytochrome c oxidase in mitochondria and increases energy metabolism, leading to cellular plasticity and cytoprotection. Recently, TLT was found to be safe and effective in the treatment of depression. Effects of TLT on ASD symptoms remains to be explored.

Sex differences in restricted repetitive behaviors and interests in children with autism spectrum disorder: An Autism Treatment Network study

Compared to the social communication domain, considerably less is known about the cause, development, and impact of restricted, repetitive behaviors interests and activities in children with autism spectrum disorder, including possible sex differences. This study examined sex differences in clinically identified (Autism Diagnostic Observation Schedule) restricted and repetitive behavior symptoms using the largest known sample (N = 1024) of age-matched and intelligence quotient-matched female and male children with autism spectrum disorder. More similarities than differences were observed; however, younger higher functioning and older lower functioning females presented reduced rates on the Autism Diagnostic Observation Schedule restricted and repetitive behavior subcategory unusually repetitive/excessive, stereotyped behaviors compared to similar males. These findings identify key restricted and repetitive behavior similarities and differences among young females and males with autism spectrum disorder and emphasize the need for a deeper understanding of the female autism phenotype.

Repetitive Transcranial Magnetic Stimulation for Treatment of Autism Spectrum Disorder: A Systematic Review and Meta-Analysis.

Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder manifesting as lifelong deficits in social communication and interaction, as well as restricted repetitive behaviors, interests and activities. While there are no specific pharmacological or other physical treatments for autism, in recent years repetitive Transcranial Magnetic Stimulation (rTMS), a technique for non-invasive neuromodulation, has attracted interest due to potential therapeutic value. Here we report the results of a systematic literature review and meta-analysis on the use of rTMS to treat ASD.Methods: We performed a systematic literature search on PubMed, Web of Science, Science Direct, Bielefeld Academic Search, and Educational Resources Information Clearinghouse. Search terms reflected diagnoses and treatment modalities of interest. Studies reporting use of rTMS to treat core ASD or cognitive symptoms in ASD were eligible. Two researchers performed article selection and data extraction independently, according to PRISMA guidelines. Changes in ASD clinical scores or in cognitive performance were the main outcomes. Random effects meta-analysis models were performed.Results: We found 23 eligible reports, comprising 4 case-reports, 7 non-controlled clinical trials, and 12 controlled clinical trials, comparing the effects of real TMS with waiting-list controls (n = 6) or sham-treatment (n = 6). Meta-analyses showed a significant, but moderate, effect on repetitive and stereotyped behaviors, social behavior, and number of errors in executive function tasks, but not other outcomes. Most studies had a moderate to high risk of bias, mostly due to lack of subject- and evaluator-blinding to treatment allocation. Only 5 studies reported stability of these gains for periods of up 6 months, with descriptions that improvements were sustained over time.Conclusions: Existing evidence supports that TMS could be useful to treat some dimensions of ASD. However, such evidence must be regarded with care, as most studies did not adequately control for placebo effects. Moreover, little is known regarding the most effective stimulation parameters, targets, and schedules. There is an urgent need for further randomized, double-blind, sham-controlled trials, with adequate follow-up periods, to test the efficacy of transcranial magnetic stimulation to treat these disorders. Available evidence must be regarded as preliminary and insufficient, at present, to support offering TMS to treat ASD.

Developmental functioning and symptom severity influence age of diagnosis in Canadian preschool children with autism.

Early diagnosis of autism spectrum disorder (ASD) is essential in most Canadian jurisdictions to access interventions that improve long-term child outcomes. Our main objective was to identify factors associated with timing of ASD diagnosis in five provinces across Canada. Factors influencing age of diagnosis were assessed in the analyses of an inception cohort of children diagnosed with ASD between ages 2 and 5 years. We examined bivariate associations and using a series of multiple variable regression models, evaluated the unique contributions of developmental functioning, ASD symptoms and demographic variables. Children with known genetic abnormalities, or severe sensory or motor impairments interfering with assessment were excluded. Participants were 421 children (84.6% boys). The mean age of diagnosis was 38.2 months (SD=8.7), an average of 19 months after parents identified initial concerns. Factors associated with later diagnosis included more advanced language and cognitive skills, and higher levels of restricted repetitive behaviour symptoms. Child sex and family demographics were not associated with age of diagnosis. In regression analyses, language and cognitive skills accounted for 6.8% of variance in age of diagnosis and ASD symptoms contributed an additional 5.5%. Provincial site accounted for 4.0% of variance in age of diagnosis, independent of developmental skills and ASD symptoms. Diagnosis of ASD occurred, on average, 19 months after parents' initial concerns. Language and cognitive skills, symptom severity and provincial site accounted for variation in age of ASD diagnosis in this Canadian cohort. Variable presentation across the developmental continuum must be considered in planning assessment services to ensure timely ASD diagnosis so that outcomes can be improved. Policy and practice leadership is also needed to reduce interprovincial variability.

Introduction to the Special Issue: Interventions to Reduce Challenging Behavior Among Individuals With Autism Spectrum Disorder.

The prevalence of autism spectrum disorder (ASD) is on the rise. In addition to the social communication skill deficits and restrictive repetitive behaviors and interests, many individuals with ASD engage in challenging behavior. Challenging behavior is associated with a multitude of negative outcomes. Challenging behavior may cause harm to the individual with ASD as well as limit opportunities for educational, vocational, and social participation and development. In addition, caregivers experience high stress and low quality of mental health. As a result, challenging behavior warrants intervention that is specifically tailored to the unique characteristics of individuals with ASD. The purpose of this Special Issue is to showcase recent research in the treatment of challenging behavior for individuals with ASD. This two-part Special Issue contains 12 studies that range from systematic and quality reviews of the intervention literature, to innovative treatment approaches, to studies that develop and evaluate treatments for restrictive and repetitive behaviors and interests.

Gender Differences During Toddlerhood in Autism Spectrum Disorder: A Prospective Community-Based Longitudinal Follow-Up Study.

Relatively few studies have examined gender differences in infants and toddlers, and most focus on clinically referred samples or high-risk infant cohorts. The current study aimed to examine gender differences in early autism manifestations and cognitive development in a community-ascertained sample. In total, 46 males and 21 females with ASD were seen at approximately 24 and 48 months of age. No significant gender differences were observed on overall cognitive ability, verbal skills, non-verbal skills, overall autism severity, or restricted repetitive behaviours. However, females were found to exhibit more social communication impairments than males. These findings may indicate that female toddlers with less severe or different, social communication impairments may be more likely to be missed during routine surveillance during toddlerhood.

Introduction to the Special Issue: Interventions to Reduce Challenging Behavior Among Individuals With Autism Spectrum Disorder.

The prevalence of autism spectrum disorder (ASD) is on the rise. In addition to the social communication skill deficits and restrictive repetitive behaviors and interests, many individuals with ASD engage in challenging behavior. Challenging behavior is associated with a multitude of negative outcomes. Challenging behavior may cause harm to the individual with ASD as well as limit opportunities for educational, vocational, and social participation and development. In addition, caregivers experience high stress and low quality of mental health. As a result, challenging behavior warrants intervention that is specifically tailored to the unique characteristics of individuals with ASD. The purpose of this Special Issue is to showcase recent research in the treatment of challenging behavior for individuals with ASD. This two-part Special Issue contains 12 studies that range from systematic and quality reviews of the intervention literature, to innovative treatment approaches, to studies that develop and evaluate treatments for restrictive and repetitive behaviors and interests.

Comprehensive Management of Autism: Current Evidence.

Autism is a neurodevelopmental disorder characterized by impaired social interaction, verbal and nonverbal communication, and restricted repetitive behavior. The goals of treatment are to target core behaviors, improve social interactions and communication, and reduce disruptive behavior. The present paper discusses the role of applied behavioral analysis and pharmacotherapy.

Diffusion tensor imaging study on white matter structure in children with autism spectrum disorder

Objective To explore the white matter microstructural change between autism spectrum disorder(ASD) children and the healthy controls and it's correlation with the age and the clinical symptoms. Methods Thirty-three patients with ASD and thirty-three healthy controls (HC) matched for sex-, age- and handedness underwent diffusion tensor imaging (DTI) scans. Use the Autism Diagnostic Observation Schedule(ADOS)and the Neuropsychological Development Inventory for Children Aged 0-6 Years Old (SLAS) to assess the clinical symptoms. Use tract-based spatial statistics (TBSS) based on fiber skeleton to analyze the fractional anisotropy (FA) of the whole brain DTI then to identify the differentiated brain regions.And analyze the correlation with age and clinical symptoms. Results (1) FA value of the body of corpus callosum(BCC)(x=-10, y=11, z=26; P=0.0012), left posterior limb of internal capsule(LPLI)(x=-23, y=-11, z=12; P<0.01), left anterior corona radiata(LACR)(x=-28, y=28, z=16; P<0.01), lift superior corona radiata(LSCR)(x=-27, y=-1, z=21; P=0.0017) was significantly lower in ASD group .(2) There was a positive correlation between the FA value of LPLI and the LACR、LSCR with age among the ASD group(r=0.436, P=0.012; r=0.443, P=0.010; r=0.475, P=0.005). There was a negative correlation between the FA value of the BCC, LPLI and the LACR, LSCR with the age among the HC children. (3) There was a correlation between the LPLI with the score of ADOS (communication: r=0.406, P=0.025; communication+ social behavior: r=0.377, P=0.039; restrictive interests and repetitive behaviors: r=0.375, P=0.041) and SLAS(gross motor: r=-0.409, P=0.024), There was a correlation between the LSCR with the score of the SLAS (gross motor: r=-0.539, P=0.002, adaptive capacity: r=-0.373, P=0.041, mental age: r=-0.388, P=0.034) . Conclusion The brain white matter microstructure change of BCC, LPLI, LACR, LSCR may be the pathophysiological basis of ASD.The development trend of brain white matter structure varied with age in ASD children is different from that of normal children. Brain white matter microstructure of the LPLI, LSCR is correlation with ASD symptoms. Key words: Autism spectrum disorder(ASD); Diffusion tensor imaging(DTI); Tract-based spatial statistics (TBSS)

Stability of Autism Symptoms in Young Children

The study of early diagnosis and intervention has been a central theme in recent autism research. In support of the validity of early autism diagnoses, researchers have found discriminating variables that are identifiable within the first three years of life. In addition, autism diagnoses made within this time period are typically stable over time. Separate symptoms, however, seem to exhibit differential patterns across development. The current study examined the stability of autism screening outcomes and symptomology in 637 toddlers between the age of 17 and 36 months. Confirmatory of previous findings, results of the current study suggest that overall screening outcomes and symptom severity across three domains (i.e., socialization/nonverbal communication, restricted repetitive behaviors and interests, and communication) are stable across time. Further, the effects of age and time between testing were found to vary between groups. Implications of these results are discussed.