Repetitive and stereotyped movements in children with autism spectrum disorders late in the second year of life

Imitation Performance in Children with Autism and the Role of Visual Attention in Imitation

In this study, we examined imitation performance, visual attention, and the relationship between imitation and visual attention of children with autism, developmental delay (DD), and typically developing (TD) children. The study findings revealed that children with autism and DD imitated less than TD children in all imitation tasks. Results also showed that children with autism spent less time looking at the model's face and movement area and more time looking at the external area. Lastly, the relationship between imitation and visual attention separated the study groups. The findings of the study provided new evidence that visual attention to movement area in children with autism was positively related to imitation performance in non-meaningful gestures.

Tele-assessment of young children referred for autism spectrum disorder evaluation during COVID-19: Associations among clinical characteristics and diagnostic outcome

The diagnosis of autism spectrum disorder (ASD) has traditionally been made through in-person evaluation. While the COVID-19 pandemic disrupted access to ASD services, there has been remarkable growth in research focused on novel ASD diagnostic practices, including the use of telemedicine. We implemented a standard ASD tele-assessment evaluation procedure, including use of a novel remote clinician-coached, caregiver-delivered ASD assessment tool (TELE-ASD-PEDS; TAP), with the goal of continuing to provide diagnostic services to young children and their families during the pandemic. We examined the relationship between child characteristics and diagnostic outcome for 335 children, ages 14-78 months, who received ASD tele-assessment conducted by psychologists and pediatricians in an outpatient clinic of a Midwestern academic medical center. We found that clinicians could make a determination about ASD diagnosis for most children (85%) evaluated using tele-assessment. Child clinical characteristics, including TAP scores and clinician ratings of ASD symptoms, were related to diagnostic outcome (i.e. diagnosis of ASD, no ASD, and Unsure about ASD). When all clinical characteristics were examined together, the presence of specific repetitive behaviors predicted ASD diagnosis. We also found that the TAP is effective for making an ASD diagnosis when used as part of comprehensive tele-assessment evaluation in children ⩾ 36 months of age with delayed language. Our study adds to an increasing body of research supporting use of tele-assessment for diagnosis of ASD. Although further research is needed, telemedicine may help families from different backgrounds and geographic locations to access high-quality diagnostic services.

Features of neurological status in children with autism spectrum disorders

The article analyzes the features of the neurological status, characterizes group differences in motor functions in children with autism spectrum disorders depending on the presence and severity of delayed psychological and speech development.

Material and methods. The analysis of data on the neurological status of children with autism spectrum disorders was based on 51 patients records for the period from 2016 to 2021; 43 boys (84%) and 8 girls (16%) aged 3 to 10 years. All patients were divided into 2 groups according to the criterion of the presence or absence of a severe delay in psychological and speech development. The first group included children with severe forms of delayed psychological and speech development — 23 (45%), the second — 28 (55%) patients with mild forms or without delayed psychological and speech development.

Results. The children in the first group were characterized by the predominance of diffuse muscular hypotension (96%); stereotypies manifested in movements looking like «wings» (22%), other stereotyped movements (48%); disorders such as echolalia, ataxia, pyramidal insufficiency syndrome, and strabismus were equally common in both groups.

Conclusion. Analysis of the data showed the predominance of several neurological disorders in children with autism spectrum disorders who have a severe delay in psychological and speech development and made it possible to identify neurological characteristics of children with autism spectrum disorders regardless of the level of psychological and speech development. 

Screening for Autism in 2-Year-Old Children: The Application of the Systematic Observation of Red Flags to the Screening Tool for Autism in Toddlers and Young Children

PURPOSE

A multimeasure approach was developed to capitalize on the strengths of two screening measures: the Screening Tool for Autism in Toddlers and Young Children (STAT), an observational measure of social communication, and the Systematic Observation of Red Flags (SORF), a checklist including restricted and repetitive behavior (RRB) items. This approach offers a novel method of identifying autism in toddlers.

METHOD

This was a retrospective study of data collected from a multidisciplinary diagnostic program for 24- to 36-month-olds with developmental delays. Raters with autism expertise but naïve to diagnoses applied the SORF to STAT videos. Psychometrics were derived for the SORF on STAT observations and a multiple-measure approach that used a Least Absolute Shrinkage and Selection Operator modeling framework to construct a STAT-SORF RRB Hybrid, retaining SORF RRB items based on individual predictive abilities.

RESULTS

The SORF alone correctly classified 84% of the sample (84% sensitivity and 86% specificity). The STAT-SORF RRB Hybrid model, which retained four SORF RRB items, correctly classified 90% of a validation sample (95% sensitivity and 75% specificity).

CONCLUSION

These findings highlight the potential utility of using multiple autism identification tools and regression-based scoring to establish presumptive eligibility and facilitate early access to autism interventions.

Restricted and repetitive behavior in children with autism during the first three years of life: A systematic review

Restricted and repetitive behavior (RRB) is a core diagnostic feature of autism spectrum disorder (ASD). Previous research shows that RRB is prevalent early in life and observed in neurotypical development as well. Less is known, however, about early RRB patterns, developmental trajectories, and the relation to outcomes for autistic children. The purpose of this systematic review was to synthesize findings from studies examining RRB in autistic children from birth through age 3. A detailed protocol was designed a priori based on PRISMA guidelines for systematic reviews. From the published literature, 41 peer reviewed journal articles were identified and included in this review. Our synthesis of the literature suggests that differences in RRB are evident prior to age 2 in children with or who go onto be diagnosed with autism. These differences were evident for both frequency and intensity of RRB across multiple topographies. There were mixed results regarding functional outcomes associated with early RRB, such as cognitive and adaptive behavior, though relations appeared to become stronger as children aged beyond toddlerhood. Notably, level of RRB appears unrelated to autism severity in young autistic children. A wide range of RRB have been reported to be elevated in autistic children during the first years of life, including repetitive motor behaviors, atypical sensory behaviors, insistence on sameness (IS), and self-injurious behaviors (SIBs). In contrast to studies of older children, RRB in very young autistic children do not appear to be associated with functional outcomes but may be valuable to include in early screening efforts.

Systematic review registration

https://osf.io/huzf3, unique identifier: doi: 10.17605/OSF.IO/HUZF3.

Can EEG Correlates Predict Treatment Efficacy in Children with Overlapping ASD and SLI Symptoms: A Case Report

Evaluation of the rehabilitation efficacy may be an essential indicator of its further implementation and planning. The research aim is to examine whether the estimation of EEG correlates of auditory-verbal processing in a child with overlapping autism spectrum disorder (ASD) and specific language impairment (SLI) symptoms may be a predictor of the treatment efficacy in conditions when behavioral tests do not show improvement during the time course. The prospective case report reports follow-up results in a child aged 36 to 66 months. During continuous integrative therapy, autism risk index, cognitive, speech-language, sensory, and EEG correlates of auditory-verbal information processing are recorded in six test periods, and their mutual interrelation was analyzed. The obtained results show a high statistically significant correlation of all observed functions with EEG correlates related to the difference between the average mean values of theta rhythm in the left (F1, F3, F7) and right (F2, F4, F8) frontal region. The temporal dynamics of the examined processes point to the consistency of the evaluated functions increasing with time flow. These findings indicate that EEG correlates of auditory-verbal processing may be used to diagnose treatment efficacy in children with overlapping ASD and SLI.

Relations of Restricted and Repetitive Behaviors to Social Skills in Toddlers with Autism

We examined the relations of restricted and repetitive behaviors (RRB; insistence on sameness, repetitive sensory-motor, self-injurious behavior) to social skills overall and aspects that comprise social skills as measured by the VABS-II (coping skills, play/leisure time, interpersonal relationships) in 24- (n = 63) and 36-month old (n = 35), high-familial-risk toddlers with ASD. Hierarchical linear regression results indicated that repetitive sensory-motor was the best predictor of social skills overall. Secondary results indicated that all three RRB subtypes were associated with each subdomain of social skills; however, repetitive sensory-motor was the strongest and most consistent among these effects. While our results suggests a general negative relation of subtypes of RRB to aspects of adaptive social function, repetitive sensory-motor behaviors may be of particular relevance to the development of social skills during toddlerhood.

Early Motor Signs in Autism Spectrum Disorder

A growing number of literature data suggest the presence of early impairments in the motor development of children with autism spectrum disorder, which could be often recognized even before the appearance of the classical social communication deficits of autism. In this narrative review, we aimed at performing an update about the available data on the early motor function in children with autism spectrum disorder. Early motor impairment in these children can manifest itself both as a mere delay of motor development and as the presence of atypicalities of motor function, such as a higher rate and a larger inventory, of stereotyped movements both with and without objects. In the perspective of a timely diagnosis, the presence of early motor signs can be an important clue, especially in an individual considered at high risk for autism. Motor and communication (both verbal and non-verbal) skills are connected and a pathogenetic role of early motor dysfunctions in the development of autism can be hypothesized. From this, derives the importance of an early enabling intervention aimed at improving motor skills, which could also have favorable effects on other aspects of development.

Biopsychological correlates of repetitive and restricted behaviors in autism spectrum disorders

BACKGROUND

Autism Spectrum Disorder (ASD) is considered a neurodevelopmental condition that is characterized by alterations in social interaction and communication, as well as patterns of restrictive and repetitive behaviors (RRBs). RRBs are defined as broad behaviors that comprise stereotypies, insistence on sameness, and attachment to objects or routines. RRBs can be divided into lower-level behaviors (motor, sensory, and object-manipulation behaviors) and higher-level behaviors (restrictive interests, insistence on sameness, and repetitive language). According to the DSM-5, the grade of severity in ASD partially depends on the frequency of RRBs and their consequences for disrupting the life of patients, affecting their adaptive skills, and increasing the need for parental support.

METHODS

We conducted a systematic review to examine the biopsychological correlates of the symptomatic domains of RRBs according to the type of RRBs (lower- or higher-level). We searched for articles from the National Library of Medicine (PubMed) using the terms: autism spectrum disorders, ASD, and autism-related to executive functions, inhibitory control, inflexibility, cognitive flexibility, hyper or hypo connectivity, and behavioral approaches. For describing the pathophysiological mechanism of ASD, we also included animal models and followed PRISMA guidelines.

RESULTS

One hundred and thirty-one articles were analyzed to explain the etiology, continuance, and clinical evolution of these behaviors observed in ASD patients throughout life.

CONCLUSIONS

Biopsychological correlates involved in the origin of RRBs include alterations in a) neurotransmission system, b) brain volume, c) inadequate levels of growth factors, d) hypo- or hyper-neural connectivity, e) impairments in behavioral inhibition, cognitive flexibility, and monitoring and f) non-stimulating environments. Understanding these lower- and higher-level of RRBs can help professionals to improve or design novel therapeutic strategies.

Repetitive behavior with objects in infants developing autism predicts diagnosis and later social behavior as early as 9 months

We evaluated repetitive behavior with objects in infants at risk for autism spectrum disorder (ASD) from 9 to 36 months of age, and associations between early repetitive behavior and social engagement. Infant siblings of children with ASD (high-risk) or typical development (low-risk) were administered a task eliciting repetitive object use at 9, 12, 15, 18, 24, and 36 months of age. Infants (n = 147) were classified into 1 of 3 outcome groups at 36 months: Low-Risk Non-ASD (n = 58), High-Risk Non-ASD (n = 72), and ASD (n = 17). Behavior was coded from video for frequencies of unusual visual inspection, spinning, and rotating behaviors. Differences in unusual visual inspection were most prominent, consistent, and present earliest: At 9 months, the ASD group engaged in this behavior more frequently than both other groups, persisting through 36 months. Differences in frequencies of spinning and rotating were later-appearing, more time-limited, and/or related to familial ASD risk rather than ultimate diagnosis. Sensitivity and specificity estimates for the presence of unusual visual inspection at 9 months of age were in the moderate range (.60 and .68, respectively) for ASD versus Low-Risk Non-ASD comparisons, generally increasing over time. Unusual visual inspection at 9 months predicted 12-month social behavior controlling for 9-month social behavior, but not vice versa, with no evidence of moderation by ASD diagnosis. In summary, unusual visual inspection of objects is present and stable by 9 months of age in infants developing ASD and predicts reduced social engagement three-months later. Close monitoring of this behavior may aid early detection. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Aberrant dynamics of cognitive control and motor circuits predict distinct restricted and repetitive behaviors in children with autism

Restricted and repetitive behaviors (RRBs) are a defining clinical feature of autism spectrum disorders (ASD). RRBs are highly heterogeneous with variable expression of circumscribed interests (CI), insistence of sameness (IS) and repetitive motor actions (RM), which are major impediments to effective functioning in individuals with ASD; yet, the neurobiological basis of CI, IS and RM is unknown. Here we evaluate a unified functional brain circuit model of RRBs and test the hypothesis that CI and IS are associated with aberrant cognitive control circuit dynamics, whereas RM is associated with aberrant motor circuit dynamics. Using task-free fMRI data from 96 children, we first demonstrate that time-varying cross-network interactions in cognitive control circuit are significantly reduced and inflexible in children with ASD, and predict CI and IS symptoms, but not RM symptoms. Furthermore, we show that time-varying cross-network interactions in motor circuit are significantly greater in children with ASD, and predict RM symptoms, but not CI or IS symptoms. We confirmed these results using cross-validation analyses. Moreover, we show that brain-clinical symptom relations are not detected with time-averaged functional connectivity analysis. Our findings provide neurobiological support for the validity of RRB subtypes and identify dissociable brain circuit dynamics as a candidate biomarker for a key clinical feature of ASD.

Towards Motor-Based Early Detection of Autism Red Flags: Enabling Technology and Exploratory Study Protocol

Observing how children manipulate objects while they are playing can help detect possible autism spectrum disorders (ASD) at an early stage. For this purpose, specialists seek the so-called “red-flags” of motor signature of ASD for more precise diagnostic tests. However, a significant drawback to achieve this is that the observation of object manipulation by the child very often is not naturalistic, as it involves the physical presence of the specialist and is typically performed in hospitals. In this framework, we present a novel Internet of Things support in the form factory of a smart toy that can be used by specialists to perform indirect and non-invasive observations of the children in naturalistic conditions. While they play with the toy, children can be observed in their own environment and without the physical presence of the specialist. We also present the technical validation of the technology and the study protocol for the refinement of the diagnostic practice based on this technology.

A systematic review of technological approaches for autism spectrum disorder assessment in children: Implications for the COVID-19 pandemic

BACKGROUND

Screening and diagnostic assessments tools for autism spectrum disorder (ASD) are important to administer during childhood to facilitate timely entry into intervention services that can promote developmental outcomes across the lifespan. However, assessment services are not always readily available to families, as they require significant time and resources. Currently, in-person screening and diagnostic assessments for ASD are limited due to the COVID-19 pandemic and will continue to be a concern for situations that limit in-person contact. Thus, it is important to expand the modalities in which child assessments are provided, including the use of technology.

AIMS

This systematic review aims to identify technologies that screen or assess for ASD in 0-12 year-old children, summarizing the current state of the field and suggesting future directions.

METHODS

An electronic database search was conducted to gather relevant articles to synthesize for this review.

OUTCOMES AND RESULTS

16 studies reported use of novel technology to assess children suspected of ASD.

CONCLUSIONS AND IMPLICATIONS

Results strongly supported live-video evaluations, video observations, and online or phone methods, but there is a need for research targeting the feasibility of these methods as it applies to the stay-at-home orders required by the pandemic, and other situations that limit clients from seeing providers in-person.

Is it autism? Some suggestions for pediatricians

An early diagnosis of autism spectrum disorder, leading to a timely enabling intervention, is associated with a better long-term prognosis and allows the early detection of any medical comorbidities that are sometimes found in individuals with autism. It is, therefore, an important challenge to begin the diagnostic procedure of these children as soon as possible. Nowadays, much progress has been made in this respect compared with the past, but considerable work remains. A fundamental role in starting a correct and timely diagnostic procedure is obviously played by the pediatrician. Today, many tools are available for the early screening of autism in the general population, but unfortunately, their real effectiveness has yet to be established. In this narrative review, we address the topic of the early diagnosis of autism spectrum disorder, emphasizing, in particular, those that are now considered the first warning signs. We list a few of the most important signs to consider when a child aged around 18 months presents to a pediatrician, subdivided into three subgroups: social-communication skills; patterns of behavior, interests, or activities; and sensory behaviors and reactivity/temperament. We deal separately with the possible presence of slight motor signs, which can also go unnoticed, but probably they should be considered as very early signs appearing even before social-communication deficits.

Recent Developments in Treatment Outcome Measures for Young Children With Autism Spectrum Disorder (ASD)

Significant advancements have been made in early intervention programs for children with Autism spectrum disorder (ASD). However, measuring treatment response for children with ASD is difficult due to the heterogeneity of changes in symptoms, which can be subtle, especially over a short period of time. Here we outline the challenge of evaluating treatment response with currently available measures as well as newly developed or refined measures that may be useful in clinical trials for young children with ASD. Continued development of treatment outcome measures will help the field identify and compare efficacious interventions and tailor treatments for children with ASD.

Early Motor Development Predicts Clinical Outcomes of Siblings at High-Risk for Autism: Insight from an Innovative Motion-Tracking Technology

Atypical motor patterns are potential early markers and predictors of later diagnosis of Autism Spectrum Disorder (ASD). This study aimed to investigate the early motor trajectories of infants at high-risk (HR) of ASD through MOVIDEA, a semi-automatic software developed to analyze 2D and 3D videos and provide objective kinematic features of their movements. MOVIDEA was developed within the Italian Network for early detection of Autism Spectrum Disorder (NIDA Network), which is currently coordinating the most extensive surveillance program for infants at risk for neurodevelopmental disorders (NDDs). MOVIDEA was applied to video recordings of 53 low-risk (LR; siblings of typically developing children) and 50 HR infants’ spontaneous movements collected at 10 days and 6, 12, 18, and 24 weeks. Participants were grouped based on their clinical outcome (18 HR received an NDD diagnosis, 32 HR and 53 LR were typically developing). Results revealed that early developmental trajectories of specific motor parameters were different in HR infants later diagnosed with NDDs from those of infants developing typically. Since MOVIDEA was useful in the association of quantitative measures with specific early motor patterns, it should be applied to the early detection of ASD/NDD markers.

Behavior and interaction imaging at 9 months of age predict autism/intellectual disability in high-risk infants with West syndrome

Automated behavior analysis are promising tools to overcome current assessment limitations in psychiatry. At 9 months of age, we recorded 32 infants with West syndrome (WS) and 19 typically developing (TD) controls during a standardized mother-infant interaction. We computed infant hand movements (HM), speech turn taking of both partners (vocalization, pause, silences, overlap) and motherese. Then, we assessed whether multimodal social signals and interactional synchrony at 9 months could predict outcomes (autism spectrum disorder (ASD) and intellectual disability (ID)) of infants with WS at 4 years. At follow-up, 10 infants developed ASD/ID (WS+). The best machine learning reached 76.47% accuracy classifying WS vs. TD and 81.25% accuracy classifying WS+ vs. WS-. The 10 best features to distinguish WS+ and WS- included a combination of infant vocalizations and HM features combined with synchrony vocalization features. These data indicate that behavioral and interaction imaging was able to predict ASD/ID in high-risk children with WS.

Multidimensional Developments and Free-Play Movement Tracking in 30- to 36-Month-Old Toddlers With Autism Spectrum Disorder Who Were Full Term

BACKGROUND

Few studies have investigated multidimensional developments and free-play movement performance in toddlers with an early diagnosis of autism spectrum disorder (ASD).

OBJECTIVE

This study compared cognitive, motor, and behavioral developments and free-play movement performance in toddlers with ASD who were full term (FT-ASD), toddlers who were full term and are typically developing (FT-TD), and toddlers who were born preterm and had a very low birth weight (VLBW-PT).

DESIGN

This was a prospective cross-sectional study.

METHODS

Forty-five 30- to 36-month-old age-matched toddlers were recruited and divided into FT-ASD, FT-TD, and VLBW-PT groups. Their developments were examined using the Mullen Scales of Early Learning; the Peabody Developmental Motor Scales, Second Edition; the Child Behavior Checklist for Ages 1.5 to 5; and the Repetitive Behavior Scale-Revised. In addition, the toddlers' free-play movements were tracked in laboratory settings using an automatic movement tracking system.

RESULTS

Toddlers with FT-ASD exhibited lower cognitive and motor scores and a higher degree of behavioral problems compared with toddlers with FT-TD or VLBW-PT. Furthermore, the movement tracking data in a free-play setting revealed that toddlers with FT-ASD displayed a higher degree of turning velocity, a higher moving time, and a higher frequency of moving toward the peripheral region compared with toddlers with FT-TD or VLBW-PT. Moreover, several motor developmental and movement-tracking indicators were found to correlate with behavioral problems and cognitive scores in toddlers with FT-ASD.

LIMITATIONS

The study results may have been affected by the small sample size, the cross-sectional design, and tracking only the whole body without subtle movements or segmental motions.

CONCLUSIONS

The findings suggest varied aspects of co-occurring developmental conditions and movement-based problems in toddlers with FT-ASD. Using standardized and sensitive measures for the early assessment of perceptuo-motor impairments is necessary for timely early intervention for such toddlers.

Psychometric analysis of the repetitive behavior scale-revised using confirmatory factor analysis in children with autism

Research examining restricted and repetitive patterns of behavior or interests (RRB) in autism spectrum disorder (ASD) has increased our understanding of its contribution to diagnosis and its role in development. Advances in our knowledge of RRB are hindered by the inconsistencies in how RRB is measured. The present study examined the factor structure of the Repetitive Behavior Scale-Revised (RBS-R) in a sample of 350 children with ASD ages 2-9. Confirmatory factor analysis designed for items with categorical response types was implemented to examine six proposed structural models. The five-factor model demonstrated the most parsimonious fit based on common overall fit indices that was further supported by examination of local model fit indicators, though, the four- and six-factor models evidenced adequate-to-good fit as well. Examination of RRB factor score approaches indicated only minor differences between summed item subscale scores and extracted factor scores with regard to associations with diagnostic measures. All RRB subtypes demonstrated significant associations with cognitive functioning and adaptive behavior. Implications for future research validating the RBS-R as a more extensive clinical measure of RRB in ASD are discussed. Autism Res 2019, 12: 1399-1410. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Repetitive behaviors are one of the two main symptoms of autism spectrum disorder (ASD). To better understand the role of repetitive behaviors, we must establish effective ways of measuring them. This study assessed the measurement qualities of the Repetitive Behavior Scale-Revised (RBS-R) in a sample of 350 children with ASD ages 2-9. We found that the RBS-R measures multiple types of repetitive behaviors and that these behaviors are related to thinking ability and independence.

Assessing subtypes of restricted and repetitive behaviour using the Adult Repetitive Behaviour Questionnaire-2 in autistic adults

Background

The majority of previous research into restricted and repetitive behaviours (RRBs) has focussed on children, partly due to a lack of suitable measures for RRBs in adults. This study aimed to explore the psychometric properties of the Adult Repetitive Behaviour Questionnaire-2 (RBQ-2A) in a large sample of autistic adults using a self-report questionnaire method.

Methods

The RBQ-2A and Autism-Spectrum Quotient (AQ) were administered online. Data from 275 autistic adults aged 18-66 (M = 36.56, SD = 12.24; 100 men and 171 women) were analysed using polychoric principal components analysis (PCA). Reliability and validity were assessed using Cronbach's alpha and correlation analyses.

Results

PCA resulted in two components of the RBQ-2A, interpretable as repetitive sensory and motor behaviours (RSMB) and insistence on sameness (IS). Both components showed acceptable internal consistency (α = .70 and .81 respectively) and were significantly moderately correlated with scores on the AQ (r _s  = .25 and .42). Participants' scores on IS were higher than their scores on RSMB. RSMB, but not IS, was negatively associated with age, particularly in older adults (≥ 50 years). There were no gender differences.

Conclusions

The RBQ-2A is a reliable and valid self-report measure of RRBs in the present sample of autistic adults. As one of the few measures of RRBs aimed at adults, it is suitable for adults with the ability to read and complete a self-report questionnaire. Results build on previous work with children using the Repetitive Behaviour Questionnaire-2 (RBQ-2).

Novelty Detection using Deep Normative Modeling for IMU-Based Abnormal Movement Monitoring in Parkinson's Disease and Autism Spectrum Disorders

Detecting and monitoring of abnormal movement behaviors in patients with Parkinson's Disease (PD) and individuals with Autism Spectrum Disorders (ASD) are beneficial for adjusting care and medical treatment in order to improve the patient's quality of life. Supervised methods commonly used in the literature need annotation of data, which is a time-consuming and costly process. In this paper, we propose deep normative modeling as a probabilistic novelty detection method, in which we model the distribution of normal human movements recorded by wearable sensors and try to detect abnormal movements in patients with PD and ASD in a novelty detection framework. In the proposed deep normative model, a movement disorder behavior is treated as an extreme of the normal range or, equivalently, as a deviation from the normal movements. Our experiments on three benchmark datasets indicate the effectiveness of the proposed method, which outperforms one-class SVM and the reconstruction-based novelty detection approaches. Our contribution opens the door toward modeling normal human movements during daily activities using wearable sensors and eventually real-time abnormal movement detection in neuro-developmental and neuro-degenerative disorders.

Sensory hypersensitivity predicts repetitive behaviours in autistic and typically-developing children

The objective of this study was to examine the relationship between sensory hypersensitivity and restricted interests and repetitive behaviours associated with autism spectrum disorder and their typically-developing peers. Furthermore, the aims included the examination of the relationship across sensory modalities and various types of restricted interests and repetitive behaviours. Data were collected from the parents of 114 children: 49 of whom were diagnosed with autism spectrum disorder and 65 typically-developing children. Parents completed the Sensory Profile 2 – Child Version and the Repetitive Behaviours Questionnaire, Second Edition. The results suggested that sensory hypersensitivity is strongly related to the core autism spectrum disorder symptom of repetitive behaviours. This relationship was not specific to autism spectrum disorder; repetitive behaviours significantly increased with sensory hypersensitivity in typically-developing individuals as well. This effect was consistent across all modalities in both autism spectrum disorder and typically developing groups; group differences were observed in the oral and tactile modalities. Furthermore, sensory hypersensitivity was significantly predictive of repetitive behaviours in all participants, autism spectrum disorder and typically-developing, and importantly, autism spectrum disorder diagnosis did not add any predictive influence above and beyond sensory hypersensitivity. Finally, sensory hypersensitivity was significantly predictive of all subdomains of repetitive behaviours, including repetitive motor movements, rigidity and adherence to routine, preoccupation with restricted patterns of interest and unusual sensory interests, and diagnosis added no predictive ability beyond sensory hypersensitivity.

Parent-Mediated Intervention for One-Year-Olds Screened as At-Risk for Autism Spectrum Disorder: A Randomized Controlled Trial

Theoretically, interventions initiated with at-risk infants prior to the point in time a definitive autism spectrum disorder (ASD) diagnosis can be made will improve outcomes. Pursuing this idea, we tested the efficacy of a parent-mediated early intervention called Adapted Responsive Teaching (ART) via a randomized controlled trial with 87 one-year-olds identified by community screening with the First Year Inventory as at-risk of later ASD diagnoses. We found minimal evidence for main effects of ART on child outcomes. However, ART group parents showed significantly greater increases in responsiveness to their infants than control group parents. Further, significant indirect (mediation) effects of assignment group on multiple child outcomes through changes in parent responsiveness supported our theory of change.

Restricted, Repetitive Behaviors in Autism Spectrum Disorder and Obsessive-Compulsive Disorder: A Comparative Review

This review paper critically examines literature regarding restricted and repetitive behaviors (RRBs) in Autism Spectrum Disorder (ASD) and Obsessive-Compulsive Disorder (OCD). The similar behavioral profiles of these disorders presents the potential for confusion regarding diagnoses and intervention efforts. As such, this review highlights the similarities and differences between RRBs in ASD and OCD. The developmental trajectories of RRBs are presented, followed by an exploration of three constructs implicated in RRB manifestation: anxiety, executive functioning, and sensory phenomena. While RRBs tend to develop with some similarity in both disorders, the differing role of anxiety highlights important distinctions between ASD and OCD. We urge researchers and clinicians to think critically about the dimensions that affect RRB presentation. Future research should use this review as a starting point to further elucidate the differences between RRBs in these two populations.

Parent-Reported Repetitive Behavior in Toddlers on the Autism Spectrum

Toddlers with autism spectrum disorder (ASD) were assessed on the Repetitive Behavior Scale-Revised (RBS-R), which we found to have acceptable internal consistency. Stereotypical subscale scores showed a negligible association with cognitive level, but correlated more strongly with adaptive and social indicators. Relative to earlier reported RBS-R scores for older age groups, toddlers' scores trended toward higher stereotyped behavior and lower ritualistic/sameness behavior. Our findings on associations with developmental indicators align with those of researchers who used more resource-intensive repetitive behavior measures. The convergence of these findings with those derived from other measurement methods suggests that the RBS-R, a cost effective parent-report measure, is a viable means of assessing repetitive behavior in toddlers with autism.

Bilateral Patterns of Repetitive Movements in 6- to 12-Month-Old Infants with Autism Spectrum Disorders

Aim: Some patterns of repetitive movements and their frequency have been proved to distinguish infants with Autism Spectrum Disorders (ASD) from infants with Typical Development (TD) and Developmental Delay (DD) from 12 months of life on. The purpose of this study is to investigate if a specific repertoire of repetitive movements is present earlier in life, and if their higher rate and duration could differentiate infants with ASD from infants with DD and TD aged between 6 and 12 months.

Method: We conducted a retrospective analysis of video-clips taken from home videos to compare the frequency and the duration of Repetitive Movement Episodes (RMEs) in a sample of 30 children equally distributed among the three groups.

Results: Significantly higher total scores in bilateral RMEs with arms, hands, fingers, and lower limbs were found to distinguish ASD infants from both DD and TD infants, with a satisfactory diagnostic efficiency. No significant difference was found between the distributions of unilateral RMEs between ASD and DD/TD.

Interpretation: Results indicate the presence at this age of an ASD-specific pattern of bilateral repetitive movements. We hypothesize a continuum between this pattern and the lack of variability in finalized and communicative movements and gestures observed in children with ASD during the second year of life.

Teaching Functional Play Skills to a Young Child with Autism Spectrum Disorder through Video Self-Modeling

The researchers used a single-case, multiple probe design across three sets of toys (i.e., farm toy, doctor's clinic toy, and rescue toy) to examine the effects of video self-modeling (VSM) on the functional play skills of a 5-year-old child with autism spectrum disorder. The findings showed a functional relation between VSM and increased percentages of functional play actions across the toy sets. The participant's percentages of the targeted functional play skills for the intervention toys remained high 1 week and 2 weeks after the intervention ceased. Additionally, preliminary generalization results showed slight improvement in the percentages of functional play actions with the generalization toys that were not directly taught. Limitations, practical implications, and directions for future research are discussed.

Psychometric analysis of the Systematic Observation of Red Flags for autism spectrum disorder in toddlers

The purpose of this study was to examine the utility of the Systematic Observation of Red Flags as an observational level-two screening measure to detect risk for autism spectrum disorder in toddlers when used with a video-recorded administration of the Communication and Symbolic Behavior Scales. Psychometric properties of the Systematic Observation of Red Flags were examined in a sample of 247 toddlers of 16- to 24 months old: 130 with autism spectrum disorder, 61 with developmental delays, and 56 typically developing. Individual items were examined for performance to create an algorithm with improved sensitivity and specificity, yielding a total Composite score and Domain scores for Social Communication and Restricted Repetitive Behaviors. Codes indicating clear symptom presence were collapsed to yield a count of the number of Red Flags for the overall scale and each symptom domain. Results indicated significant group differences with large effects for the Composite, both Domain scores, and Red Flags score, and good discrimination (area under the curve = 0.84-0.87) between autism spectrum disorder and nonspectrum groups for the Composite, Social Communication Domain, and Social Communication Red Flags score. The Systematic Observation of Red Flags provides an observational screening measure for 16- to 24-month-olds with good discrimination, sensitivity, and specificity. A cutoff of 20 on the Composite is recommended to optimally detect autism spectrum disorder risk.

Two years changes in the development of caudate nucleus are involved in restricted repetitive behaviors in 2-5-year-old children with autism spectrum disorder

Caudate nucleus volume is enlarged in autism spectrum disorder (ASD) and is associated with restricted and repetitive behaviors (RRBs). However, the trajectory of caudate nucleus volume in RRBs of young children remains unclear. Caudate nucleus volume was measured in 36 children with ASD and 18 matched 2-3-year-old subjects with developmentally delayed (DD) at baseline (Time 1) and at 2-year follow-up (Time 2). The differential growth rate in caudate nucleus volume was calculated. Further, the relationships between the development of caudate nucleus volume and RRBs were analyzed. Our results showed that caudate nucleus volume was significantly larger in the ASD group at both time points and the magnitude of enlargement was greater at Time 2. The rate of caudate nucleus growth during this 2-year interval was faster in children with ASD than DD. Right caudate nucleus volume growth was negatively correlated with RRBs. Findings from this study suggest developmental abnormalities of caudate nucleus volume in ASD. Longitudinal MRI studies are needed to explore the correlation between atypical growth patterns of caudate nucleus and phenotype of RRBs.

A comparison of the effects of rhythm and robotic interventions on repetitive behaviors and affective states of children with Autism Spectrum Disorder (ASD)

Repetitive behaviors and poor affect regulation are commonly seen in children with Autism Spectrum Disorder (ASD). We compared the effects of two novel interventions - rhythm and robotic therapies, with those of a standard-of-care intervention, on the repetitive behaviors and affective states of 36 children with ASD between 5 and 12 years using a randomized controlled trial design. We coded for frequencies of sensory, negative, and stereotyped behaviors and the duration of positive, negative, and interested affective states in children during early, mid, and late training sessions. In terms of repetitive behaviors, in the early session, the rhythm and robot groups engaged in greater negative behaviors, whereas the comparison group engaged in greater sensory behaviors. With training, the rhythm group reduced negative behaviors whereas there were no training-related changes in the other groups. In terms of affective states, the rhythm and robot groups showed greater negative affect, whereas the comparison group demonstrated greater interested affect across all sessions. With training, the rhythm group showed a reduction in negative affect and an increase in interested affect whereas the robot group showed a reduction in positive affect. Overall, it appears that rhythm-based interventions are socially engaging treatment tools to target core impairments in autism.

Visual attention to competing social and object images by preschool children with autism spectrum disorder

Eye tracking studies of young children with autism spectrum disorder (ASD) report a reduction in social attention and an increase in visual attention to non-social stimuli, including objects related to circumscribed interests (CI) (e.g., trains). In the current study, fifteen preschoolers with ASD and 15 typically developing controls matched on gender and age (range 24-62 months) were eye tracked while viewing a paired preference task of face and object stimuli. While co-varying verbal and nonverbal developmental quotients, preschoolers with ASD were similar to controls in their visual attention to faces presented with objects unrelated to CI, but attended significantly less than controls to faces presented with CI-related objects. This was consistent across three metrics: preference, prioritization and duration. Social attention in preschoolers with ASD therefore appears modulated by salience of competing non-social stimuli, which may affect the development of both social and non-social characteristics of the disorder.

Repetitive behavior in 12-month-olds later classified with autism spectrum disorder

OBJECTIVE

As compared to the utility of early emerging social communicative risk markers for predicting a later diagnosis of autism spectrum disorder (ASD), less is known about the relevance of early patterns of restricted and repetitive behaviors. We examined patterns of stereotyped motor mannerisms and repetitive manipulation of objects in 12-month-olds at high and low risk for developing ASD, all of whom were assessed for ASD at 24 months.

METHOD

Observational coding of repetitive object manipulation and stereotyped motor behaviors in digital recordings of the Communication and Symbolic Behavior Scales was conducted using the Repetitive and Stereotyped Movement Scales for 3 groups of 12-month-olds: low-risk infants (LR, n = 53); high-familial-risk infants who did not meet diagnostic criteria for ASD at 24 months (HR-negative, n = 75); and high-familial-risk infants who met diagnostic criteria for ASD at 24 months (HR-ASD, n = 30).

RESULTS

The HR-ASD group showed significantly more stereotyped motor mannerisms than both the HR-negative group (p = .025) and the LR group (p = .001). The HR-ASD and HR-negative groups demonstrated statistically equivalent repetitive object manipulation scores (p = .431), and both groups showed significantly more repetitive object manipulation than the LR group (p < .040). Combining the motor and object stereotypy scores into a Repetitive and Stereotyped Movement Scales (RSMS) composite yielded a disorder-continuum effect such that each group was significantly different from one another (LR < HR-negative < HR-ASD).

CONCLUSION

These results suggest that targeted assessment of repetitive behavior during infancy may augment early ASD identification efforts.

Longitudinal patterns of repetitive behavior in toddlers with autism

BACKGROUND

Recent evidence suggests that restricted and repetitive behaviors may differentiate children who develop autism spectrum disorder (ASD) by late infancy. How these core symptoms manifest early in life, particularly among infants at high risk for the disorder, is not well characterized.

METHODS

Prospective, longitudinal parent-report data (Repetitive Behavior Scales-Revised) were collected for 190 high-risk toddlers and 60 low-risk controls from 12 to 24 months of age. Forty-one high-risk children were classified with ASD at age 2. Profiles of repetitive behavior were compared between groups using generalized estimating equations.

RESULTS

Longitudinal profiles for children diagnosed with ASD differed significantly from high- and low-risk children without the disorder on all measures of repetitive behavior. High-risk toddlers without ASD were intermediate to low risk and ASD positive counterparts. Toddlers with ASD showed significantly higher rates of repetitive behavior across subtypes at the 12-month time point. Repetitive behaviors were significantly correlated with adaptive behavior and socialization scores among children with ASD at 24 months of age, but were largely unrelated to measures of general cognitive ability.

CONCLUSIONS

These findings suggest that as early as 12 months of age, a broad range of repetitive behaviors are highly elevated in children who go on to develop ASD. While some degree of repetitive behavior is elemental to typical early development, the extent of these behaviors among children who develop ASD appears highly atypical.

What do repetitive and stereotyped movements mean for infant siblings of children with autism spectrum disorders?

Repetitive and stereotyped movements (RSMs) in infancy are associated with later diagnoses of autism spectrum disorder (ASD), yet this relationship has not been fully explored in high-risk populations. The current study investigated how RSMs involving object and body use are related to diagnostic outcomes in infant siblings of children with ASD (Sibs-ASD) and typically developing children (Sibs-TD). The rate and number of different types of RSMs were measured at an average of 15 months with follow-up diagnostic evaluations approximately 18 months later. While Sibs-ASD displayed higher rates of RSMs relative to Sibs-TD, rates did not differ according to diagnostic outcome in Sibs-ASD. However preliminary evidence suggests that qualitative differences in RSM type warrant further investigation as early diagnostic markers.

A comparative study of primary and secondary stereotypies

This study compares primary stereotypies (repetitive, self-stimulating, and seemingly nonsensical movements that can occur within typically developing children) and secondary stereotypies (those occurring within autistic or mentally retarded children). Utilizing a retrospective chart review from 1995 to 2010, the current study compares primary and secondary stereotypies by the application of a classification system that organizes the movement by its type (motor only, phonic only, mixed) and complexity. In addition, it investigates other parameters associated with the movements such as duration, frequency, age, functional impairment, and progression. The sample group consisted of 28 primary and 28 secondary cases. Primary stereotypies were predominantly motor, simple, of shorter duration, and of less frequency, whereas secondary stereotypies had more vocalization, complexity, longer durations, and higher frequencies. Moreover, functional impairment due to stereotypies was noted in 3 primary and 7 secondary cases, and worsening of stereotypies was noted in 70% of primary versus 44% of secondary cases.

Neural markers of errors as endophenotypes in neuropsychiatric disorders

Learning from errors is fundamental to adaptive human behavior. It requires detecting errors, evaluating what went wrong, and adjusting behavior accordingly. These dynamic adjustments are at the heart of behavioral flexibility and accumulating evidence suggests that deficient error processing contributes to maladaptively rigid and repetitive behavior in a range of neuropsychiatric disorders. Neuroimaging and electrophysiological studies reveal highly reliable neural markers of error processing. In this review, we evaluate the evidence that abnormalities in these neural markers can serve as sensitive endophenotypes of neuropsychiatric disorders. We describe the behavioral and neural hallmarks of error processing, their mediation by common genetic polymorphisms, and impairments in schizophrenia, obsessive-compulsive disorder, and autism spectrum disorders. We conclude that neural markers of errors meet several important criteria as endophenotypes including heritability, established neuroanatomical and neurochemical substrates, association with neuropsychiatric disorders, presence in syndromally-unaffected family members, and evidence of genetic mediation. Understanding the mechanisms of error processing deficits in neuropsychiatric disorders may provide novel neural and behavioral targets for treatment and sensitive surrogate markers of treatment response. Treating error processing deficits may improve functional outcome since error signals provide crucial information for flexible adaptation to changing environments. Given the dearth of effective interventions for cognitive deficits in neuropsychiatric disorders, this represents a potentially promising approach.

Brief report: repetitive behaviors in young children with autism spectrum disorder and developmentally similar peers: a follow up to Watt et al. (2008)

The present study extended the findings of Watt et al. (J Autism Dev Disord 38:1518-1533, 2008) by investigating repetitive and stereotyped behaviors (RSB) demonstrated by children (n = 50) and typical development (TD; n = 50) matched on developmental age, gender, and parents' education level. RSB were coded from videotaped Communication and Symbolic Behavior Scales Behavior Samples (Wetherby and Prizant 2002) using the Noldus Pro Observer© video software. Children with ASD demonstrated significantly higher frequencies of RSB with body objects excluding categories involving banging or tapping objects or surfaces. Behaviors demonstrated by both groups indicated overlapping RSB profiles at this age. These findings highlight the significance of RSB in the early identification and support the need for future research to further determine ASD-specific RSB.

Evidence of a distinct behavioral phenotype in young boys with fragile X syndrome and autism

OBJECTIVE

How does the behavioral expression of autism in fragile X syndrome (FXS + Aut) compare with idiopathic autism (iAut)? Although social impairments and restricted, repetitive behaviors are common to these variants of autism, closer examination of these symptom domains may reveal meaningful similarities and differences. To this end, the specific behaviors comprising the social and repetitive behavioral domains in young children with FXS + Aut and iAut were profiled.

METHOD

Twenty-three male subjects 3 to 5 years old with FXS + Aut were matched by age to a group of 38 boys with iAut. Repetitive behavior was assessed using the Repetitive Behavior Scales-Revised. Social behavior was evaluated using Autism Diagnostic Observation Schedule social item severity scores.

RESULTS

Rates of stereotypy, self-injury, and sameness behaviors did not differ between groups, whereas compulsive and ritual behavior scores were significantly lower for subjects with FXS + Aut compared with those with iAut. Those with FXS + Aut scored significantly lower (less severe) than the iAut group on five Autism Diagnostic Observation Schedule measurements of social behavior: gaze integration, quality of social overtures, social smile, facial expressions, and response to joint attention.

CONCLUSIONS

The behavioral phenotype of FXS + Aut and iAut are most similar with respect to lower-order (motoric) restricted, repetitive behaviors and social approach, but differ in more complex forms of restricted, repetitive behaviors and some social response behaviors. These findings highlight the phenotypic heterogeneity of autism overall and its unique presentation in an etiologically distinct condition.

Examining restricted and repetitive behaviors in young children with autism spectrum disorder during two observational contexts

This prospective study of the FIRST WORDS® Project examined restricted and repetitive behaviors in a sample of 55 toddlers at a mean age of 20 months who were later diagnosed with autism spectrum disorder. Restricted and repetitive behaviors were coded using the Repetitive Movement and Restricted Interest Scales in two video-recorded observation methods–structured sampling procedures in a clinic and naturalistic everyday activities at home. Measures of restricted and repetitive behaviors were higher in the clinic setting than in the home observation, especially for behaviors involving object use. Repetitive movements with objects in the clinic predicted nonverbal developmental scores and Autism Diagnostic Observation Schedule social affect scores at later follow-up. In contrast, repetitive movements with objects at home significantly predicted later Autism Diagnostic Observation Schedule restricted and repetitive behaviors scores. These results support the utility of the Repetitive Movement and Restricted Interest Scales to detect restricted and repetitive behaviors in toddlers and suggest that observations of restricted and repetitive behaviors in clinic and home settings may provide unique and important diagnostic information for improving early detection of autism spectrum disorder.

Relationship between executive functions and motor stereotypies in children with Autistic Disorder

This study reports on the relationship between motor stereotypies and impairments in executive functions (EF) in children with Autistic Disorder (AD) and in children with Developmental Language Disorders (DLD). We hypothesized that low EF performance would predict higher frequency and longer durations of stereotypies in the AD group only. Twenty-two children (age range = 7-9 years, 6 months, girls = 5) with AD were recruited from a longitudinal multi-site study and compared to twenty-two non-autistic children with DLD (age range = 7-9 years, 6 months, girls = 5). The two groups were matched on non-verbal IQ and demographic characteristics. Frequency and duration of stereotypies were coded from videotaped semi-structured play sessions. EF measures included the Wisconsin Card Sorting Task (WCST) Categories, Wechsler Intelligence Scale for Children-Revised (WISC-R) Mazes, and Stanford-Binet Fourth Edition (SB-IV) Matrices. The scores for frequency and duration of stereotypies were higher in the AD group. Separate linear regressions revealed that group status, EF, and their interactions predict stereotypies. Specifically, lower EF scores predicted higher frequencies and longer durations of stereotypies in the AD group only. Analyses controlled for age, gender, and parent education. Findings suggest that in AD, EF impairments and stereotypies may be linked to shared brain pathways.

Evidence-based behavioral interventions for repetitive behaviors in autism

Restricted and repetitive behaviors (RRBs) are a core symptom of autism spectrum disorders (ASD). There has been an increased research emphasis on repetitive behaviors; however, this research primarily has focused on phenomenology and mechanisms. Thus, the knowledge base on interventions is lagging behind other areas of research. The literature suggests there are evidence-based practices to treat "lower order" RRBs in ASD (e.g., stereotypies); yet, there is a lack of a focused program of intervention research for "higher order" behaviors (e.g., insistence on sameness). This paper will (a) discuss barriers to intervention development for RRBs; (b) review evidence-based interventions to treat RRBs in ASD, with a focus on higher order behaviors; and (c) conclude with recommendations for practice and research.

Modified exposure and response prevention to treat the repetitive behaviors of a child with autism: a case report

We report the case study of a school-aged child with autism whose repetitive behaviors were treated with a modified version of a technique routinely used in cognitive behavior therapy (i.e., exposure response prevention) to treat obsessive-compulsive disorder. A trained behavioral therapist administered the modified ERP treatment over the course of an intensive two-week treatment period with two therapy sessions occurring daily. The treatment was successful at decreasing the amount of child distress and cooccurring problem behavior displayed; however, the child's interest in the repetitive behavior eliciting stimulus (i.e., puzzles) remained. The case study demonstrates specific ways that exposure response prevention strategies can be adapted to the unique kinds of repetitive behaviors that present clinically in autism. A larger clinical trial is needed to substantiate these findings.

Brief report: Circumscribed attention in young children with autism

School-aged children and adolescents with autism demonstrate circumscribed attentional patterns to nonsocial aspects of complex visual arrays (Sasson et al. 2008). The current study downward extended these findings to a sample of 2-5 year-olds with autism and 2-5 year-old typically developing children. Eye-tracking was used to quantify discrete aspects of visual attention to picture arrays containing combinations of social pictures, pictures of objects frequently involved in circumscribed interests in persons with autism (e.g., trains), and pictures of more commonplace objects (e.g., clothing). The children with autism exhibited greater exploration and perseverative attention on objects related to circumscribed interests than did typically developing children. Results suggest that circumscribed attention may be an early emerging characteristic of autism.

Basal ganglia morphometry and repetitive behavior in young children with autism spectrum disorder

We investigated repetitive and stereotyped behavior (RSB) and its relationship to morphometric measures of the basal ganglia and thalami in 3- to 4-year-old children with autism spectrum disorder (ASD; n = 77) and developmental delay without autism (DD; n = 34). Children were assessed through clinical evaluation and parent report using RSB-specific scales extracted from the Autism Diagnostic Observation Schedule (ADOS), the Autism Diagnostic Interview, and the Aberrant Behavior Checklist. A subset of children with ASD (n = 45), DD (n = 14), and a group of children with typical development (TD; n = 25) were also assessed by magnetic resonance imaging. Children with ASD demonstrated elevated RSB across all measures compared to children with DD. Enlargement of the left and right striatum, more specifically the left and right putamen, and left caudate, was observed in the ASD compared to the TD group. However, nuclei were not significantly enlarged after controlling for cerebral volume. The DD group, in comparison to the ASD group, demonstrated smaller thalami and basal ganglia regions even when scaled for cerebral volume, with the exception of the left striatum, left putamen, and right putamen. Elevated RSB, as measured by the ADOS, was associated with decreased volumes in several brain regions: left thalamus, right globus pallidus, left and right putamen, right striatum and a trend for left globus pallidus and left striatum within the ASD group. These results confirm earlier reports that RSB is common early in the clinical course of ASD and, furthermore, demonstrate that such behaviors may be associated with decreased volumes of the basal ganglia and thalamus.

The Genetics of Autism

This chapter is written to make the fast-paced, expanding field of the genetics of autism accessible to those practitioners who help children with autism. New genetic knowledge and technology have quickly developed over the past 30 years, particularly within the past decade, and have made many optimistic about our ability to explain autism. Among these advances include the sequencing of the human genome (Lander et al., 2001) and the identification of common genetic variants via the HapMap project (International HapMap Consortium, 2005), and the development of cost-efficient genotyping and analysis technologies (Losh, Sullivan, Trembath, & Piven, 2008). Improvement in technology has led to improved visualization of chromosomal abnormality down to the molecular level. The four most common syndromes associated with autism include fragile X syndrome, tuberous sclerosis, 15q duplications, and untreated phenylketonuria (PKU; Costa e Silva, 2008). FXS and 15q duplications are discussed within the context of cytogenetics. TSC is illustrated within the description of linkage analysis.

Stereotypic movement disorder: easily missed

AIM

To expand the understanding of stereotypic movement disorder (SMD) and its differentiation from tics and autistic stereotypies.

METHOD

Forty-two children (31 males, mean age 6y 3mo, SD 2y 8mo; 11 females, mean age 6y 7mo, SD 1y 9mo) consecutively diagnosed with SMD, without-self-injurious behavior, intellectual disability, sensory impairment, or an autistic spectrum disorder (ASD), were assessed in a neuropsychiatry clinic. A list of probe questions on the nature of the stereotypy was administered to parents (and to children if developmentally ready). Questionnaires administered included the Stereotypy Severity Scale, Short Sensory Profile, Strengths and Difficulties Questionnaire, Repetitive Behavior Scale--Revised, and the Developmental Coordination Disorder Questionnaire. The stereotyped movement patterns were directly observed and in some cases further documented by video recordings made by parents. The probe questions were used again on follow-up at a mean age of 10 years 7 months (SD 4y 4mo).

RESULTS

Mean age at onset was 17 months. Males exceeded females by 3:1. Family history of a pattern of SMD was reported in 13 and neuropsychiatric comorbidity in 30 (attention-deficit-hyperactivity disorder in 16, tics in 18, and developmental coordination disorder in 16). Obsessive-compulsive disorder occurred in only two. The Short Sensory Profile correlated with comorbidity (p<0.001), the Stereotypy Severity Scale (p=0.009), and the Repetitive Behavior Scale (p<0.001); the last correlated with the Stereotypy Severity Scale (p=0.001). Children (but not their parents) liked their movements, which were usually associated with excitement or imaginative play. Mean length of follow-up was 4 years 8 months (SD 2y 10mo). Of the 39 children followed for longer than 6 months, the behavior stopped or was gradually shaped so as to occur primarily privately in 25. Misdiagnosis was common: 26 were initially referred as tics, 10 as ASD, five as compulsions, and one as epilepsy. Co-occurring facial grimacing in 15 children and vocalization in 22 contributed to diagnostic confusion.

INTERPRETATION

SMD occurs in children without ASD or intellectual disability. The generally favorable clinical course is largely due to a gradual increase in private expression of the movements. Severity of the stereotypy is associated with sensory differences and psychopathology. Differentiation of SMD from tics and ASD is important to avoid misdiagnosis and unnecessary treatment.