A screening instrument for autism at 18 months of age: a 6-year follow-up study

Prospective identification of autism spectrum disorders in infancy and toddlerhood using developmental surveillance: the social attention and communication study

OBJECTIVE

Despite behavioral markers of autism spectrum disorders (ASDs) being evident within the first year of life, there remains little research on the prospective identification of these children in a community-based setting before 18 months. The aim in the Social Attention and Communication Study was to identify infants and toddlers at risk of an ASD during their first 2 years.

METHODS

A total of 241 Maternal and Child Health nurses were trained on the early signs of ASDs at 8, 12, 18 and 24 months. Using a developmental surveillance approach with a community-based sample, a cohort of 20,770 children was monitored on early social attention and communication behaviors. Those infants/toddlers identified as "at risk" were referred to the Social Attention and Communication Study team from 12 months for developmental and diagnostic assessments at 6 monthly intervals, until 24 months.

RESULTS

A total of 216 children were referred, with 110 being further assessed. Of these, 89 children were classified with an ASD at 24 months, and 20 children had developmental and/or language delays, resulting in a Positive Predictive value of 81%. The estimated rate of ASDs in the Social Attention and Communication Study cohort ranged from 1:119 to 1:233 children. Estimated sensitivity ranged from 69% to 83.8%, and estimated specificity ranged from 99.8% to 99.9%.

CONCLUSION

Developmental surveillance of social and communication behaviors, which differ according to the age at which the child is monitored, enables the accurate identification of children at risk for ASDs between 12 and 24 months. Education on the early signs is recommended for all primary health care professionals to facilitate early identification of ASDs.

The prodrome of autism: early behavioral and biological signs, regression, peri- and post-natal development and genetics

Autism is one of the most heritable neurodevelopmental conditions and has an early onset, with symptoms being required to be present in the first 3 years of life in order to meet criteria for the 'core' disorder in the classification systems. As such, the focus on identifying a prodrome over the past 20 years has been on pre-clinical signs or indicators that will be present very early in life, certainly in infancy. A number of novel lines of investigation have been used to this end, including retrospective coding of home videos, prospective population screening and 'high risk' sibling studies; as well as the investigation of pre- and peri-natal, brain developmental and other biological factors. While no single prodromal sign is expected to be present in all cases, a picture is emerging of indicative prodromal signs in infancy and initial studies are being undertaken to attempt to ameliorate early presentation and even 'prevent' emergence of the full syndrome.

Validation of rapid neurodevelopmental assessment instrument for under-two-year-old children in Bangladesh

OBJECTIVE

The objective of this study was to determine the reliability and validity of a comprehensive assessment procedure for ascertaining neurodevelopmental status of children aged 0 to 24 months for use by multidisciplinary professionals in a developing country.

METHODS

We developed the Rapid Neurodevelopmental Assessment (RNDA) to determine functional status in the following domains: primitive reflexes, gross motor, fine motor, vision, hearing, speech, cognition, behavior, and seizures. Reliability was determined for 50 children who were aged <3 months and 30 children who were aged > or =3 to 24 months and were administered the RNDA by 8 different professionals (3 physicians, 4 therapists, and 1 special teacher). Validity was determined on 34 children aged <3 months in hospital and 81 children aged > or =3 to 24 months in urban (n = 47) and rural (n = 34) community-based populations by any 1 of the 8 professionals, with simultaneous administration of the adapted Bayley Scales of Infant Development II by a psychologist as the gold standard.

RESULTS

Mean kappa coefficients of agreement among professionals in overall and individual domains in the 2 age groups ranged from good to excellent. For both younger and older children, there was good concurrent validity (ie, significantly lower mean Mental Development Index and Psychomotor Development Index scores) for children with > or =1 neurodevelopmental impairment and for children with impairments in most functional domains, compared with children with no impairments. Significantly more impairments were found in children from disadvantaged compared with socioeconomically more advantaged communities, indicating good discriminant validity.

CONCLUSIONS

The RNDA can be used by professionals from a range of backgrounds with high reliability and validity for determining functional status of children who are younger than 2 years. The study findings have important practical implications for early identification and intervention to mitigate neurodevelopmental impairments in large populations that live in developing countries where professional expertise is sparse.

Timing of increased autistic disorder cumulative incidence

Autistic disorder (AD) is a severe neurodevelopmental disorder typically identified in early childhood. Both genetic and environmental factors are implicated in its etiology. The number of individuals identified as having autism has increased dramatically in recent years, but whether some proportion of this increase is real is unknown. If real, susceptible populations may have exposure to controllable exogenous stressors. Using literature AD data from long-term (approximately 10-year) studies, we determined cumulative incidence of AD for each cohort within each study. These data for each study were examined for a changepoint year in which the AD cumulative incidence first increased. We used data sets from Denmark, California, Japan, and a worldwide composite of studies. In the Danish, California, and worldwide data sets, we found that an increase in AD cumulative incidence began about 1988-1989. The Japanese study (1988-1996) had AD cumulative incidence increasing continuously, and no changepoint year could be calculated. Although the debate about the nature of increasing autism continues, the potential for this increase to be real and involve exogenous environmental stressors exists. The timing of an increase in autism incidence may help in screening for potential candidate environmental stressors.

Genetic variance for autism screening items in an unselected sample of toddler-age twins

OBJECTIVE

Twin and family studies of autistic traits and of cases diagnosed with autism suggest high heritability; however, the heritability of autistic traits in toddlers has not been investigated. Therefore, this study's goals were (1) to screen a statewide twin population using items similar to the six critical social and communication items widely used for autism screening in toddlers (Modified Checklist for Autism in Toddlers); (2) to assess the endorsement rates of these items in a general population; and (3) to determine their heritability.

METHOD

Participants composed a statewide, unselected twin population. Screening items were administered to mothers of 1,211 pairs of twins between 2 and 3 years of age. Twin similarity was calculated via concordance rates and tetrachoric and intraclass correlations, and the contribution of genetic and environmental factors was estimated with single-threshold ordinal models.

RESULTS

The population-based twin sample generated endorsement rates on the analogs of the six critical items similar to those reported by the scale's authors, which they used to determine an autism threshold. Current twin similarity and model-fitting analyses also used this threshold. Casewise concordance rates for monozygotic (43%) and dizygotic (20%) twins suggested moderate heritability of these early autism indicators in the general population. Variance component estimates from model-fitting also suggested moderate heritability of categorical scores.

CONCLUSIONS

Autism screener scores are moderately heritable in 2- to 3-year-old twin children from a population-based twin panel. Inferences about sex differences are limited by the scarcity of females who scored above the threshold on the toddler-age screener.

Begleitsymptomatik bei tief greifenden Entwicklungsstörungen

Fragestellung: Neuere Untersuchungen belegen eine höhere Prävalenz für autistische Störungen als die ersten epidemiologischen Untersuchungen erwarten ließen. In dieser Untersuchung wird überprüft, wie häufig eine Intelligenzminderung sowie komorbide psychiatrische Störungen in einer klinischen Stichprobe von Patienten mit tief greifenden Entwicklungsstörungen anzutreffen sind. Methodik: Die Stichprobe besteht aus 601 Patienten mit einer tief greifenden Entwicklungsstörung. Für alle Patienten wurde das Intelligenzniveau bestimmt. Auf Achse I wurden bis zu zwei weitere Diagnosen kodiert sowie behandlungsrelevante Symptome erfasst (Ess- und Schlafstörungen, autoaggressives Verhalten), auf den Achsen V und VI die psychosozialen Belastungsfaktoren und das Gesamtniveau der psychosozialen Anpassung. Ergebnisse: Bei 26 % der Patienten lag das Intelligenzniveau im Normbereich (N = 158). 54 % aller Patienten (N = 325) hatten eine, 19 % (N = 110) zwei weitere psychiatrische Diagnosen. Die häufigsten Diagnosen waren externalisierende Störungen (N = 221). Internalisierende (N = 96) und sonstige Störungen (N = 114) kamen nur halb so oft vor. Autoaggressives Verhalten lag vor allem bei schweren Intelligenzminderungen vor. Es gab einen signifikanten Zusammenhang zwischen dem Auftreten von (auto-)aggressivem Verhalten und dem Ausmaß der psychosozialen Anpassung. Schlussfolgerungen: Patienten mit tief greifenden Entwicklungsstörungen zeigen eine Vielzahl komorbider Symptome. Das Vorliegen externalisierender Störungen beeinträchtigt die psychosoziale Anpassung.

Risk of autism and increasing maternal and paternal age in a large north American population

Previous studies are inconsistent regarding whether there are independent effects of maternal and paternal age on the risk of autism. Different biologic mechanisms are suggested by maternal and paternal age effects. The study population included all California singletons born in 1989-2002 (n = 7,550,026). Children with autism (n = 23,311) were identified through the California Department of Developmental Services and compared with the remainder of the study population, with parental ages and covariates obtained from birth certificates. Adjusted odds ratios and 95% confidence intervals were used to evaluate the risk of autism associated with increasing maternal and paternal age. In adjusted models that included age of the other parent and demographic covariates, a 10-year increase in maternal age was associated with a 38% increase in the odds ratio for autism (odds ratio = 1.38, 95% confidence interval: 1.32, 1.44), and a 10-year increase in paternal age was associated with a 22% increase (odds ratio = 1.22, 95% confidence interval: 1.18, 1.26). Maternal and paternal age effects were seen in subgroups defined by race/ethnicity and other covariates and were of greater magnitude among first-born compared with later-born children. Further studies are needed to help clarify the biologic mechanisms involved in the independent association of autism risk with increasing maternal and paternal age.

Communicative acts of children with autism spectrum disorders in the second year of life

PURPOSE

To examine the communicative profiles of children with autism spectrum disorders (ASD) in the second year of life.

METHOD

Communicative acts were examined in 125 children 18 to 24 months of age: 50 later diagnosed with ASD; 25 with developmental delays (DD); and 50 with typical development (TD). Precise measures of rate, functions, and means of communication were obtained through systematic observation of videotaped behavior samples from the Communication and Symbolic Behavior Scales Developmental Profile (A. Wetherby & B. Prizant, 2002).

RESULTS

Children with ASD communicated at a significantly lower rate than children with DD and TD. The ASD group used a significantly lower proportion of acts for joint attention and a significantly lower proportion of deictic gestures with a reliance on more primitive gestures compared with the DD and TD groups. Children with ASD who did communicate for joint attention were as likely as other children to coordinate vocalizations, eye gaze, and gestures. Rate of communicative acts and joint attention were the strongest predictors of verbal outcome at age 3.

CONCLUSION

By 18 to 24 months of age, children later diagnosed with ASD showed a unique profile of communication, with core deficits in communication rate, joint attention, and communicative gestures.

[Clinical features in autism]

Autism is a neurodevelopmental disorder diagnosed on the basis of three behaviorally altered domains: social deficits, impaired language and communication, and stereotyped and repetitive behaviors. The early recognition of the disorder, as early as 2 years, is an important challenge, because early treatments are more efficient in helping children to develop their adaptation skills, allowing their better integration in the society, with less suffering and a lower level of handicap. Therefore, we describe the symptoms that may lead first degree practitioners to suspect autistic disorders as early as possible, and how they can help the children and their parents to be directed to the appropriate services for diagnostic and treatment.

Extraction and Refinement Strategy for detection of autism in 18-month-olds: a guarantee of higher sensitivity and specificity in the process of mass screening

BACKGROUND

For early detection of autism, it is difficult to maintain an efficient level of sensitivity and specificity based on observational data from a single screening. The Extraction and Refinement (E&R) Strategy utilizes a public children's health surveillance program to produce maximum efficacy in early detection of autism. In the extraction stage, all cases at risk of childhood problems, including developmental abnormality, are identified; in the refinement stage, cases without problems are excluded, leaving only cases with conclusive diagnoses.

METHODS

The city of Yokohama, Japan, conducts a routine child health surveillance program for children at 18 months in which specialized public health nurses administer YACHT-18 (Young Autism and other developmental disorders CHeckup Tool), a screening instrument to identify children at risk for developmental disorders. Children who screen positive undergo further observation, and those without disorders are subsequently excluded. To study the efficacy of early detection procedures for developmental disorders, including autism, 2,814 children born in 1988, examined at 18 months of age, and not already receiving treatment for diseases or disorders were selected.

RESULTS

In the extraction stage, 402 (14.3%) children were identified for follow-up. In the refinement stage, 19 (.7%) of these were referred to the Yokohama Rehabilitation Center and diagnosed with developmental disorders. The extraction stage produced four false negatives, bringing total diagnoses of developmental disorders to 23 (.8%) - including 5 with autistic disorder and 9 with pervasive developmental disorder - not otherwise specified (PDDNOS). Sensitivity was 60% for autistic disorder and 82.6% for developmental disorders. Specificity for developmental disorders rose to 100% with the E&R Strategy. Picture cards used in YACHT-18 provided a finer screen that excluded some false positive cases.

CONCLUSIONS

An extraction and refinement methodology utilizing child health surveillance programs achieve high efficacy for early detection of autism.

Autism Spectrum Disorders in Young Children

Retrospective research studies, videotape analyses of children later diagnosed with autism spectrum disorders (ASD), and recent studies on younger siblings of children diagnosed with ASD, at high-risk of ASD, provide evidence of the early signs of ASD in children as young as 12 months. This article provides a review of early identification, diagnostic assessment, and treatment for young children (0-5 years old) with ASD. Several screening tools as well as comprehensive assessment measures are described. The authors also discuss how the family context is affected by the diagnosis, in terms of adaptation to the diagnosis and to treatment. Finally, the authors present a brief review of interventions for young children with ASD.

Epidemiology of pervasive developmental disorders

This article reviews the results of 43 studies published since 1966 that provided estimates for the prevalence of pervasive developmental disorders (PDDs), including autistic disorder, Asperger disorder, PDD not otherwise specified, and childhood disintegrative disorder. The prevalence of autistic disorder has increased in recent surveys and current estimates of prevalence are around 20/10,000, whereas the prevalence for PDD not otherwise specified is around 30/10,000 in recent surveys. Prevalence of Asperger disorder is much lower than that for autistic disorder and childhood disintegrative disorder is a very rare disorder with a prevalence of about 2/100,000. Combined all together, recent studies that have examined the whole spectrum of PDDs have consistently provided estimates in the 60-70/10,000 range, making PDD one of the most frequent childhood neurodevelopmental disorders. The meaning of the increase in prevalence in recent decades is reviewed. There is evidence that the broadening of the concept, the expansion of diagnostic criteria, the development of services, and improved awareness of the condition have played a major role in explaining this increase, although it cannot be ruled out that other factors might have also contributed to that trend.

The Social Aptitudes Scale: an initial validation

BACKGROUND

Poor social skills are associated with a range of child and adolescent psychiatric disorders, with deficits being particularly marked in autistic spectrum disorders (ASDs). Here, we validate a brief measure of social aptitudes where low scores are designed to index a substantially raised risk of ASDs.

METHOD

Parents of a national community sample of 7,977 British 5-16 year olds completed the Social Aptitudes Scale (SAS) as well as a general questionnaire measure of psychopathology, the Strengths and Difficulties Questionnaire (SDQ). Psychiatric diagnoses were assigned by clinical raters on the basis of detailed multi-informant information.

RESULTS

All ten items of the SAS loaded onto a single latent factor, with a Cronbach's alpha of 0.88. Correlations between the SAS and the SDQ were only modest, suggesting that the SAS measures different attributes to the SDQ. The SAS was significantly better than the SDQ at identifying ASDs.

CONCLUSION

Children and adolescents with low SAS scores are at increased risk of mental health problems, particularly ASDs.

The reliability and validity of the Turkish version of the brief infant-toddler social emotional assessment (BITSEA)

In this study the reliability and validity of the Turkish version of the brief infant-toddler social emotional assessment (BITSEA) were investigated in a community sample. The sample consisted of 462 children (mean age: 24.60+/-7.93 [12-42] months) who had applied to Turkish health centers for immunization. Both parents completed the BITSEA; mothers completed the child behavior checklist 2/3 (CBCL). Internal consistencies of the BITSEA-problem (P) and competence (C) scales were good to excellent (Cronbach's alpha=0.82 and 0.72, respectively). Interrater reliability between parents and test-retest reliability were good. BITSEA/P scores were significantly correlated with CBCL internalizing, externalizing and total problem scores (p<0.001). Maternal BITSEA/P cutpoint scores revealed that 30.6% of male toddlers and 28.6% of females were in the subclinical range and 13.1% of males and 17.6% of females were in clinical range. Results reveal that the Turkish version of BITSEA is a reliable, valid and simply applicable instrument for screening social, emotional and behavioral problems among toddlers. Clinical validation of the BITSEA/C and BITSEA/P is warranted.

Clinical assessment and management of toddlers with suspected autism spectrum disorder: insights from studies of high-risk infants

With increased public awareness of the early signs and recent American Academy of Pediatrics recommendations that all 18- and 24-month-olds be screened for autism spectrum disorders, there is an increasing need for diagnostic assessment of very young children. However, unique challenges exist in applying current diagnostic guidelines for autism spectrum disorders to children under the age of 2 years. In this article, we address challenges related to early detection, diagnosis, and treatment of autism spectrum disorders in this age group. We provide a comprehensive review of findings from recent studies on the early development of children with autism spectrum disorders, summarizing current knowledge on early signs of autism spectrum disorders, the screening properties of early detection tools, and current best practice for diagnostic assessment of autism spectrum disorders before 2 years of age. We also outline principles of effective intervention for children under the age of 2 with suspected/confirmed autism spectrum disorders. It is hoped that ongoing studies will provide an even stronger foundation for evidence-based diagnostic and intervention approaches for this critically important age group.

Prevalence of treated autism spectrum disorders in Aruba

To study autism outside of a narrow range of settings previously studied, and in a particularly distinctive setting in the Caribbean. The aim of the Aruba Autism Project was to determine the prevalence of autism spectrum disorders (ASDs) in birth years 1990–1999 in Aruba. A record review study was conducted; cases were ascertained from children treated at the Child & Adolescent Psychiatry Clinic of Aruba, the first and only child psychiatry service on the island. In these 10 birth years we found a prevalence for autistic disorder (AD) of 1.9 per 1,000 (95% CI 1.2–2.8) and for autism spectrum disorders of 5.3 per 1,000 (95% CI 4.1–6.7). Comparison analysis with a cumulative incidence report from the UK, showed a similar cumulative incidence to age five in Aruba. Prevalence of ASDs in birth years 1990–1999 and cumulative incidence to age five in Aruba are similar to recent reports from the United Kingdom and the United States.

Hyperbaric treatment for children with autism: a multicenter, randomized, double-blind, controlled trial

Background

Several uncontrolled studies of hyperbaric treatment in children with autism have reported clinical improvements; however, this treatment has not been evaluated to date with a controlled study. We performed a multicenter, randomized, double-blind, controlled trial to assess the efficacy of hyperbaric treatment in children with autism.

Methods

62 children with autism recruited from 6 centers, ages 2–7 years (mean 4.92 ± 1.21), were randomly assigned to 40 hourly treatments of either hyperbaric treatment at 1.3 atmosphere (atm) and 24% oxygen ("treatment group", n = 33) or slightly pressurized room air at 1.03 atm and 21% oxygen ("control group", n = 29). Outcome measures included Clinical Global Impression (CGI) scale, Aberrant Behavior Checklist (ABC), and Autism Treatment Evaluation Checklist (ATEC).

Results

After 40 sessions, mean physician CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0008), receptive language (p < 0.0001), social interaction (p = 0.0473), and eye contact (p = 0.0102); 9/30 children (30%) in the treatment group were rated as "very much improved" or "much improved" compared to 2/26 (8%) of controls (p = 0.0471); 24/30 (80%) in the treatment group improved compared to 10/26 (38%) of controls (p = 0.0024). Mean parental CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0336), receptive language (p = 0.0168), and eye contact (p = 0.0322). On the ABC, significant improvements were observed in the treatment group in total score, irritability, stereotypy, hyperactivity, and speech (p < 0.03 for each), but not in the control group. In the treatment group compared to the control group, mean changes on the ABC total score and subscales were similar except a greater number of children improved in irritability (p = 0.0311). On the ATEC, sensory/cognitive awareness significantly improved (p = 0.0367) in the treatment group compared to the control group. Post-hoc analysis indicated that children over age 5 and children with lower initial autism severity had the most robust improvements. Hyperbaric treatment was safe and well-tolerated.

Conclusion

Children with autism who received hyperbaric treatment at 1.3 atm and 24% oxygen for 40 hourly sessions had significant improvements in overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to children who received slightly pressurized room air.

Trial Registration

clinicaltrials.gov NCT00335790

New developments in autism

The substantial increase in the prevalence of autism necessitates that practicing physicians become more familiar with the presentation of symptoms to improve early diagnoses and interventions, thus improving the prognosis for affected children. Autism is a complex neurodevelopmental disorder with a triad of core impairments in social interactions, repetitive behaviors, and communication. Clinically, autism appears as a spectrum, with many variations in the severity of defining behaviors and associated symptoms among children. Although the etiology of autism is unknown, it is thought to involve a genetic susceptibility that may be triggered by environmental factors. Because of the high variability in behaviors, biologic findings, and response to treatment, many specialists are assuming a theory of many different autisms, each of which may have a somewhat different etiology and response to treatment. Although there is no known cure for autism, many treatments are available to improve core and associated symptoms.

Reduced change blindness suggests enhanced attention to detail in individuals with autism

BACKGROUND

The phenomenon of change blindness illustrates that a limited number of items within the visual scene are attended to at any one time. It has been suggested that individuals with autism focus attention on less contextually relevant aspects of the visual scene, show superior perceptual discrimination and notice details which are often ignored by typical observers.

METHODS

In this study we investigated change blindness in autism by asking participants to detect continuity errors deliberately introduced into a short film. Whether the continuity errors involved central/marginal or social/non-social aspects of the visual scene was varied. Thirty adolescent participants, 15 with autistic spectrum disorder (ASD) and 15 typically developing (TD) controls participated.

RESULTS

The participants with ASD detected significantly more errors than the TD participants. Both groups identified more errors involving central rather than marginal aspects of the scene, although this effect was larger in the TD participants. There was no difference in the number of social or non-social errors detected by either group of participants.

CONCLUSION

In line with previous data suggesting an abnormally broad attentional spotlight and enhanced perceptual function in individuals with ASD, the results of this study suggest enhanced awareness of the visual scene in ASD. The results of this study could reflect superior top-down control of visual search in autism, enhanced perceptual function, or inefficient filtering of visual information in ASD.

Tourette syndrome and comorbid pervasive developmental disorders

We examined the rates of comorbid pervasive developmental disorders in participants with Tourette syndrome. We used 7288 participants from the Tourette Syndrome International Database Consortium Registry. We found 334 (4.6%; 1 of every 22 participants) with Tourette syndrome had a comorbid pervasive developmental disorder. In participants with Tourette syndrome and comorbid pervasive developmental disorders, 98.8% had one or more comorbidities (pervasive developmental disorder was not counted) compared to 13.2% in the group of participants with Tourette syndrome only. Variables from logistic modeling that were significant predictors of Tourette syndrome and pervasive developmental disorders were: male gender; no family history of tics/Tourette syndrome; and an increased number of comorbidities (P < .001). We found rates of comorbid Tourette syndrome and pervasive developmental disorders to be increased by 13 times. Identification of differences between subgroups of patients with Tourette syndrome may increase understanding of syndromal susceptibility, severity, and outcome.

Asperger's syndrome in adulthood

INTRODUCTION

Asperger's syndrome is one of the autism spectrum disorders. Affected individuals display considerably impaired capacity for social interaction, unusual special interests, and a tendency towards ritualized behavior.

METHODS

The etiology, symptoms, diagnosis, and treatment of Asperger's syndrome in adulthood are outlined on the basis of a selective literature review via Medline and information in relevant reference books. Furthermore, the authors report their personal experience at a special clinic for adults.

RESULTS

Asperger's syndrome in adulthood can be diagnosed by thorough anamnesis, heteroanamnesis-with emphasis on childhood-and painstaking clinical examination. The considerable psychosocial impairments affect the patients' professional, social, and private lives. The precise etiology is still unknown, but a multifactorial origin with genetic, neurobiological, and psychosocial components appears probable. Although no specific, empirically tested treatment concepts have yet been established, psychotherapeutic elements (structuring and directive interventions) seem to be helpful, together with pharmacotherapy-if indicated-in the presence of comorbidity.

CONCLUSIONS

Asperger's syndrome should be included in the differential diagnosis of adults who display the corresponding symptoms. The etiopathogenesis and treatment of Asperger's syndrome in adulthood should be further investigated.

Sensitivity and specificity of the Modified Checklist for Autism in Toddlers and the Social Communication Questionnaire in preschoolers suspected of having pervasive developmental disorders

This study assessed the psychometric properties of the Modified Checklist for Autism in Toddlers (M-CHAT) and the Social Communication Questionnaire (SCQ) in a sample of preschool children referred for possible pervasive developmental disorders (PDDs). The sample consisted of 82 children between the ages of 18 and 70 months (54 with a PDD diagnosis and 28 with non-PDD diagnoses). M-CHAT scores were analyzed for 56 children aged 18-48 months old and SCQ scores were analyzed for 65 children aged 30-70 months old. Optimal sensitivity and specificity were achieved using the cutoff score of any three items on the M-CHAT and lowering the cutoff score of the SCQ. The diagnostic agreement of both instruments was also compared in an overlapping subsample of 39 children aged 30-48 months. Overall, the M-CHAT and SCQ appear to more accurately classify children with PDDs who have lower intellectual and adaptive functioning.

Screening for autism spectrum disorders in primary care settings

The need for autism-specific screening during pediatric well-child visits has been established. However, additional support for specific screening instruments is needed. The current study used the Modified Checklist for Autism in Toddlers (M-CHAT) and the M-CHAT Follow-Up Interview to screen 4797 children during toddler checkups. Of the 4797 cases, 466 screened positive on the M-CHAT; of the 362 who completed the follow-up interview, 61 continued to show risk for autism spectrum disorders (ASDs). A total of 41 children have been evaluated; 21 children have been diagnosed with ASD, 17 were classified with non-ASD delays, and three were typically developing. The PPV of M-CHAT plus interview was .57. It is notable that only four of the 21 cases of ASD were flagged by their pediatrician. These findings suggest that the M-CHAT is effective in identifying ASD in primary care settings. Future research will follow this sample longitudinally.

Validation of the Infant-Toddler Checklist as a broadband screener for autism spectrum disorders from 9 to 24 months of age

There is an urgent requirement for the improvement of early detection of ASDs. This article provides a brief review of research on the accuracy of screeners for children with ASD that have been administered to general pediatric samples and then present results of a population-based study with a broadband screener to detect children with communication delays including children with ASD.

Diagnosticando o transtorno autista: aspectos fundamentais e considerações práticas

Tendo como base modelos de prática diagnóstica implementados em outros países, o objetivo do artigo é oferecer uma revisão geral acerca do que vem a ser o transtorno autista e dos fatores críticos que devem ser considerados durante o processo diagnóstico. São discutidos aspectos dos critérios diagnósticos e também das comorbidades, incidência, etiologia e diretrizes para a prática diagnóstica. Tais diretrizes incluem formas de exploração de sintomas de risco durante exames de rotina realizados por profissionais que trabalham com a população infantil e elementos básicos necessários para a realização de uma avaliação minuciosa e criteriosa por uma equipe interdisciplinar. Isso inclui, por exemplo, o uso de instrumentos específicos auxiliares no diagnóstico, elementos importantes para a avaliação médica e psicológica e encaminhamentos para serviços adequados de intervenção e apoio.

The rise in autism and the role of age at diagnosis

BACKGROUND

Autism prevalence in California, based on individuals eligible for state-funded services, rose throughout the 1990s. The extent to which this trend is explained by changes in age at diagnosis or inclusion of milder cases has not been previously evaluated.

METHODS

Autism cases were identified from 1990 through 2006 in databases of the California Department of Developmental Services, which coordinates services for individuals with specific developmental disorders. The main outcomes were population incident cases younger than age 10 years for each quarter, cumulative incidence by age and birth year, age-specific incidence rates stratified by birth year, and proportions of diagnoses by age across birth years.

RESULTS

Autism incidence in children rose throughout the period. Cumulative incidence to 5 years of age per 10,000 births rose consistently from 6.2 for 1990 births to 42.5 for 2001 births. Age-specific incidence rates increased most steeply for 2- and 3-year olds. The proportion diagnosed by age 5 years increased only slightly, from 54% for 1990 births to 61% for 1996 births. Changing age at diagnosis can explain a 12% increase, and inclusion of milder cases, a 56% increase.

CONCLUSIONS

Autism incidence in California shows no sign yet of plateauing. Younger ages at diagnosis, differential migration, changes in diagnostic criteria, and inclusion of milder cases do not fully explain the observed increases. Other artifacts have yet to be quantified, and as a result, the extent to which the continued rise represents a true increase in the occurrence of autism remains unclear.

Recognition and treatment of Asperger syndrome in the community

SOURCES OF DATA

We conducted a systematic review of the current literature for this review, but as there are many gaps in the research literature, we have supplemented this by our own clinical experience.

AREAS OF AGREEMENT

There is a general agreement that Asperger syndrome (AS) is one of the autistic spectrum disorders, that it is a developmental disorder which is either present at birth or develops shortly after and that there is a strong hereditary component.

AREAS OF CONTROVERSY

The fundamental impairment of AS is in the social arena, but what causes this is disputed. We propose that it is a disorder of non-verbal communication. Another important area of controversy is the extent to which AS may remit.

GROWING POINTS

Many people with AS develop secondary psychiatric disorders in adolescence and adulthood, some of which may be linked genetically, notably bipolar disorder [DeLong R, Nohria C (1994) Psychiatric family history and neurological disease in autistic spectrum disorders. Dev Med Child Neurol, 36, 441-448] or be explicable by some other association, but many patients and carers attribute their anxiety and low mood to bullying. The prevalence, treatment and prevention of co-morbid mental health problems are rapidly developing areas of interest. Some people with AS are known to commit offences, and when they commit they are more likely to be violent offences against strangers. How much of a risk that is presented by people with AS, and how to assess this risk, is another growing area of concern.

AREAS TIMELY FOR DEVELOPING RESEARCH

The social impairments of people with AS include deficits in empathy, self-awareness and executive function. Many of these are quintessentially human characteristics, and the study of people with AS provides opportunities for using neuroimaging to compare people with AS and controls and identify which areas of the brain are concerned with these 'higher functions'. The study of AS, like that of other fronto-striatal disorders, is also throwing light on the role of networks in the brain and on how networks are formed during embryogenesis.

Inter-rater reliability and stability of diagnoses of autism spectrum disorder in children identified through screening at a very young age

To examine the inter-rater reliability and stability of autism spectrum disorder (ASD) diagnoses made at a very early age in children identified through a screening procedure around 14 months of age. In a prospective design, preschoolers were recruited from a screening study for ASD. The inter-rater reliability of the diagnosis of ASD was measured through an independent assessment of a randomly selected subsample of 38 patients by two other psychiatrists. The diagnoses at 23 months and 42 months of 131 patients, based on the clinical assessment and the diagnostic classifications of standardised instruments, were compared to evaluate stability of the diagnosis of ASD. Inter-rater reliability on a diagnosis of ASD versus non-ASD at 23 months was 87% with a weighted kappa of 0.74 (SE 0.11). The stability of the different diagnoses in the autism spectrum was 63% for autistic disorder, 54% for pervasive developmental disorder, not otherwise specified (PDD-NOS), and 91% for the whole category of ASD. Most diagnostic changes at 42 months were within the autism spectrum from autistic disorder to PDD-NOS and were mainly due to diminished symptom severity. Children who moved outside the ASD category at 42 months made significantly larger gains in cognitive and language skills than children with a stable ASD diagnosis. In conclusion, the inter-rater reliability and stability of the diagnoses of ASD established at 23 months in this population-based sample of very young children are good.

Brief report: The level and nature of autistic intelligence revisited

Owing to higher performance on the Raven's Progressive Matrices (RPM) than on the Wechsler Intelligence Scales (WIS), it has recently been argued that intelligence is underestimated in autism. This study examined RPM and WIS IQs in 48 individuals with autism, a mixed clinical (n = 28) and a neurotypical (n = 25) control group. Average RPM IQ was higher than WIS IQ only in the autism group, albeit to a much lesser degree than previously reported and only for individuals with WIS IQs <85. Consequently, and given the importance of reliable multidimensional IQ estimates in autism, the WIS are recommended as first choice IQ measure in high functioning individuals. Additional testing with the RPM might be required in the lower end of the spectrum.

Tradução para o português da escala M-CHAT para rastreamento precoce de autismo

INTRODUÇÃO: A escala Modified Checklist for Autism in Toddlers (M-CHAT) é um instrumento de rastreamento precoce de autismo, que visa identificar indícios desse transtorno em crianças entre 18 e 24 meses. Deve ser aplicada nos pais ou cuidadores da criança. É auto-aplicável e simples, e apresenta alta sensibilidade e especificidade. Foi desenvolvida no idioma inglês e ainda não está disponível uma versão em português. Na literatura não existe consenso quanto à técnica de tradução, sendo a adaptação transcultural uma das formas possíveis. O objetivo do presente estudo foi realizar a tradução do inglês para o português do Brasil da escala M-CHAT para rastreio precoce do autismo, respeitando a equivalência transcultural. MÉTODO: Foi obtida permissão da autora da escala, realizada tradução, seguida de sua respectiva back-translation, avaliação da equivalência referencial, primeiro pré-teste em amostra da população-alvo, avaliação da equivalência geral, avaliação de especialistas em autismo infantil, elaboração da versão preliminar, segundo pré-teste em pais de crianças de ambulatório de pediatria do SUS e elaboração da versão final. RESULTADOS: A avaliação da equivalência referencial demonstrou que 78% das questões eram semelhantes, 13% aproximadas e 9% diferentes. Das 20 pessoas interrogadas no primeiro pré-teste 9 entenderam 100% das questões. O segundo pré-teste demonstrou boa aceitação e entendimento pela população-alvo, com 70% dessa sem nenhuma queixa. Após as avaliações pormenorizadas foi elaborada a versão final. CONCLUSÃO: O estudo torna disponível a versão em português da escala M-CHAT, considerada adequada por especialistas e compreensível pela população.

Exploration of core features of a human face by healthy and autistic adults analyzed by visual scanning

Autism is a neurodevelopmental disorder characterized by disorders in social interaction and emotional reciprocity which can be explained by impairments of the ability to understand the mental states of others ("theory of mind") and recognition of facial expressions. These impairments may be related to the difficulties with face recognition characteristic of this disorder. Face perception plays a critical role in the development of social interaction and understanding of the internal emotional state of others. It depends on initial oculomotor exploration. The aim of this study was to quantify ocular behaviour in 11 adults with autism and 23 healthy subjects (15-35 years) while exploring neutral faces and faces expressing an emotion using an eye tracking method. The strategy used to explore faces was also studied. All subjects spent significantly more time on the eye region than on the rest of the face. However, subjects with autism spent less time on the eye region than healthy subjects. The latter used a strategy based on their own eye dominance when exploring faces. All healthy subjects significantly began their exploration of a face by looking at the eye in the contralateral visual field to their dominant eye. This strategy seemed to be impaired in patients with autism. To conclude, these results contrast with earlier reports regarding the lack of interest in the eye region in patients with autism, and demonstrate for the first time that perception of the face is dependent on eye dominance.

One-year change in repetitive behaviours in young children with communication disorders including autism

Repetitive behaviours are a relatively neglected area of study in autism. Previous research has concluded that repetitive behaviour is inversely related to ability and that it tends to increase over the preschool years. One-hundred and four children ages 24-48 months, with autism, autism spectrum disorder (ASD) or other disorders, were followed for 13 months. Twelve items from the Autism Diagnostic Interview (ADI-R) were analysed, as well as diagnostic algorithm scores. Ability was related to degree of repetitive behaviours, except for one cluster of relatively able children. ADI-R repetitive behaviour algorithm scores increased over time; however, when all 12 behaviours were considered, there was a general decrease in impact upon the child's and family's activities. Reasons for this decrease are discussed.

What's new in autism?

This review on autism spectrum disorder (ASD) focusses on recent insights in the clinical picture, such as continuity of the phenotype and the concept of broader phenotype, on epidemiology and on clinical issues relevant to physicians, including new methods for early screening and diagnosis, psychiatric and somatic co-morbidity, and the expansion of so-called complementary and alternative treatments. ASD is a disorder with mainly genetic causes and recent insights show that a variety of genetic mechanisms may be involved, i.e. single gene disorders, copy number variations and polygenic mechanisms. Technological advances in genetics have lead to a number of promising findings, which, together with other lines of fundamental research, suggest that ASD may be a disorder of connectivity in the brain, at least in a subgroup of patients. It is possible that part of the genetic load in autism actually reflects gene-environment interaction, but there is no evidence for purely environmental causes in a substantial number of cases. Clinical research suggests that ASD may be a multi-system disorder in at least a subgroup of subjects, affecting the gastro-intestinal (GI) tract, the immune system and perhaps other systems. Behavioural treatments remain the cornerstone of management, and are mainly aimed at stimulation of the domains of impaired development and reducing secondary behaviours. These treatments are constantly being refined, but the main progress in this area may be the increase of research on effectiveness.

Screening strategies for autism spectrum disorders in pediatric primary care

BACKGROUND

Two strategies have been proposed for early identification of children with autism spectrum disorders (ASD): (1) using a general screening tool followed by an ASD-specific screening tool for those who screen positive on the former or (2) using an ASD-specific tool for all children. The relative yield of these two strategies has not been examined.

OBJECTIVES

This study compared the number of children identified at risk for ASD at their well child visits between the ages of 18 and 30 months using a general developmental screening tool and an autism-specific screening tool.

METHODS

The Parents' Evaluation of Developmental Status (PEDS) was used as the general developmental screening tool and the Modified Checklist for Autism in Toddlers (M-CHAT) was used as the autism-specific tool. These tools were administered concurrently to 152 children.

RESULTS

Cross tabulations and chi tests were used to determine the utility of the PEDS as the first step of a two-part screen for ASD. Of those who screened positive for developmental concerns on the PEDS (n = 38), 16% screened positive for ASD on the M-CHAT; of those who did not screen positive for developmental concerns on the PEDS (n = 114), 14% screened positive for ASD on the M-CHAT (p = .79).

CONCLUSION

The PEDS missed the majority of children who screened positive for ASD on the M-CHAT, suggesting that these two tools tap into very different domains of developmental concerns. The findings support the use of an ASD-specific tool for all children in conjunction with regular standardized developmental screening.

The modified checklist for autism in toddlers: a follow-up study investigating the early detection of autism spectrum disorders

Autism spectrum disorders (ASD) often go undetected in toddlers. The Modified Checklist for Autism in Toddlers (M-CHAT) was used to screen 3,793 children aged 16-30 months from low- and high-risk sources; screen positive cases were diagnostically evaluated. Rescreening was performed on 1,416 children aged 42-54 months. Time 1 Positive Predictive Value (PPV) was .36 for the initial screening and .74 for the screening plus follow-up telephone interview; values were similar for Time2 PPV. When separating referral sources, PPV was low for the low-risk sample but acceptable with the followup telephone interview. Children with ASD from the low-risk and high-risk samples were highly similar. Results indicate that the M-CHAT continues to be a promising instrument for the early detection of ASD.

The prevalence of autism in Australia. Can it be established from existing data?

AIM

To assess whether existing data collection mechanisms can provide accurate and sufficient information about the prevalence of autism in Australia.

METHODS

Summary data about the number of children aged 0-16 years known to have an autism spectrum disorder (ASD) were gathered from State and Territory health, disability, education sources and autism associations. Summary data were also provided by national sources. Initial contact was made by letter, and follow-up was undertaken by telephone or email.

RESULTS

For the years 2003-2004, the estimated prevalence of autism for 6- to 12-year-olds ranged from 9.6 to 40.8/10 000 for the State and Territory data, and from 12.1 to 35.7/10 000 for the national data. There was a similar variation in prevalence estimates for children aged 0-5 and 13-16 years. There was also a variation in prevalence estimates between age groups.

CONCLUSION

Inconsistencies in autism prevalence estimates calculated from existing data sources suggest that further efforts are needed to ensure the collection of reliable information about the prevalence of ASD for national, State and Territory use. Existing data systems need to be improved or additional data systems need to be developed to ensure the collection of reliable information. Reliable and consistent ASD prevalence data would ensure that services are being provided to those who need them and would enhance the opportunities to undertake meaningful population-based research.

Cognitive, behavior and intervention outcome in young children with autism

The relations between cognition and autism severity, head size and intervention outcome, were examined. Change in cognitive level with intervention was measured in children with autism and compared to children with developmental disabilities (DD). Eighty-one children (mean age 25.9 months) with autism (n=44) and DD (n=37) were assessed at pre- and post 1 year of intervention. Cognitive abilities and autism severity were measured by standardized tests. Three pre-intervention cognitive level groups: normal (IQ>90), borderline (70<IQ<89) and impaired (50<IQ<69) were examined. The impaired group had more severe autism symptoms than the borderline and the normal cognitive groups. However, following intervention the groups did not differ in the change in core autism symptoms. IQ scores increased significantly more in the autism group than in the DD group. IQ improvements correlated significantly with reduction in autism symptoms and mostly in stereotyped behaviors.

CONCLUSIONS

Cognitive ability in autism is associated with autism severity. Two distinct subtypes based on cognitive level are identified. However, baseline cognitive level cannot predict the progress rate in autism symptoms with intervention. Improvement of social-communicative behaviors and the intensive intervention are related to significant cognitive increments in autism.

Use of the Screening Tool for Autism in Two-Year-Olds (STAT) for children under 24 months

The study examined the properties of the Screening Tool for Autism in Two-Year-Olds (STAT) for children under 24 months. The STAT provides a standard context for observing social-communicative behavior in play, imitation, and communication. Seventy-one children received the STAT between 12 and 23 months of age and a follow-up diagnostic evaluation after 24 months. All had an older sibling with an autism spectrum diagnosis ( n = 59) or had been referred for evaluation for concerns about autism ( n = 12). Signal detection analysis resulted in a cut score of 2.75 for this sample, which yielded a sensitivity of 0.95, specificity of 0.73, positive predictive value of 0.56, and negative predictive value of 0.97. False positives were highest for the 12- to 13-month-old age group; STAT screening properties were improved when the sample was limited to children 14 months and older. Implications for using the STAT with children under 24 months are discussed.

Screening for autism in older and younger toddlers with the Modified Checklist for Autism in Toddlers

The Modified Checklist for Autism in Toddlers (M—CHAT) was used to screen younger (16—23 months) versus older (24—30 months) high- and low-risk toddlers. Refusal rates for follow-up interview showed no group differences, but parents of younger/low-risk children were more likely to refuse evaluation than parents of high-risk children. PPP for an ASD diagnosis was: younger/high-risk 0.79, older/high-risk 0.74, younger/low-risk 0.28, and older/low-risk 0.61, with PPP differing by age within the low-risk group. Most of the children in all groups, however, were diagnosed with a developmental disorder. Symptom severity generally did not differ among groups. Cognitive and adaptive measures showed minimal group differences. Therefore, older and younger toddlers had similar symptomatology and developmental delays; PPP for ASD is better at 24 than 18 months for low-risk children; however, these children are still highly likely to show a developmental disorder. Clinical decision making should balance early identification against the lower specificity of M—CHAT screening for the younger/low-risk group.

Positive and negative gaze perception in autism spectrum conditions

Eyes are key social features providing a wealth of information about the attention, interest, emotion, and intention of others. Humans are typically very adept at detecting gaze direction, but there is a large decrement in gaze discrimination ability when eye images change from positive to negative polarity. This is thought to show an expert system for gaze perception that applies a contrast-specific heuristic to determine where someone else is looking. Autism spectrum conditions (ASC) are characterized by social deficits including difficulties in face-processing and in the social use of gaze. People with ASC are thought to have less expertise for gaze processing compared to typical controls, though little research has tested this. We investigated gaze direction perception in typical males and females, and males with ASC using facial stimuli with positive or negative polarity of the eyes. Results showed that the ASC group was worse at judging gaze direction with positive stimuli, and showed less of a decrement in performance when eye stimuli changed from positive to negative polarity. The differences in gaze perception for the ASC group were most evident when information from the eyes was more difficult and ambiguous. Typical females performed better at gaze direction detection with positive polarity than typical males, who in turn performed better than males with ASC. This latter finding is consistent with the extreme male brain theory of autism, and with the idea that people with ASC have less gaze expertise.