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Biomedical subjects

Tony Charman

Publications and source records attributed to Tony Charman.

32 records · Page 2Linked to original sources
PubMed2003

Measuring early language development in preschool children with autism spectrum disorder using the MacArthur Communicative Development Inventory (Infant Form).

Parent report data on early language development measured using the MacArthur Communicative Development Inventory (CDI-Infant Form) was collected on 134 preschool children with autism spectrum disorder. The pattern of development of understanding of phrases, word comprehension and expression, and production of gestures, was compared to the typical pattern. In common with typical development there was considerable variability in language acquisition, although for the group as a whole this was significantly delayed compared to the normal course. In addition, atypical patterns were identified in the emergence of language skills in the sample. Comprehension of words was delayed in comparison to word production, and production of early gestures (involving sharing reference) was delayed relative to production of later gestures (involving use of objects). However, other aspects of language development were similar to that found in typically developing infants, including word comprehension being in advance of word production in absolute terms, gesture production acting as a 'bridge' between word comprehension and word production and the broad pattern of acquisition across word categories and word forms. The implications for assessment and intervention with preschool children with autism spectrum disorder are discussed.

Age Factors↗
PubMed2003

Features of autism in Rett syndrome and severe mental retardation.

It has long been recognized that there is phenotypic overlap between Rett syndrome (RS) and autism. Advances in our clinical and genetic understanding of RS over the past decade have made clear that the cause and course of RS and autism are distinct (except perhaps in a few cases). Despite this, further delineation of the phenotypic overlap between RS and autism is warranted to enhance clinical decision-making and to further understanding of neuropathological development in both disorders. The present study measured autistic symptoms using the Autism Behavior Checklist (ABC) in a sample of girls with RS and a comparison group of girls with severe and profound mental retardation (SMR). Controlling for developmental level and motor ability, girls with RS scored more highly than those with SMR on the Sensory and Relating subscales. In contrast, there were no group differences on the Body and Object use, Language and Social and Self-help subscales. Further work on the characterisation of the behavioral phenotype of genetic disorders such as RS and autism may aid in identifying the neuropathogenic processes that lead from gene-to-brain-to-behavior.

Adolescent↗
PubMed2003

Towards a behavioral phenotype for Rett syndrome.

Despite considerable interest in Rett syndrome, there have been few studies of associated behavioral and emotional problems. In the present study, 143 girls with Rett syndrome were compared on the Developmental Behavior Checklist with 85 girls with severe to profound mental retardation of mixed etiologies. After controlling for the effects of physical disabilities, we found that the girls with Rett syndrome presented more "autistic-relating" and fewer antisocial behaviors. A subsample of children with autism was also compared to the girls with Rett syndrome on autistic-relating behaviors, revealing that the Rett syndrome group did not present with classic autistic behavioral features The implications of these results for the identification of a Rett syndrome behavioral phenotype are discussed.

Child↗
PubMed2003

Epidemiology and early identification of autism: research challenges and opportunities.

Recent studies suggest that the prevalence of autism spectrum disorders may be as high as 60 per 10000, considerably greater than the long-accepted figure of 5 per 10 000 for classic autism. Increased recognition, the broadening of the diagnostic concept and methodological differences across studies may account for most or all of the apparent increase in prevalence, although this cannot be quantified. In addition to the implications for families and services, these conceptual changes will affect the scientific study of autism. At present, case definition is reliant on the behavioural and developmental picture alone. Because the behavioural phenotype of autism and the broader autism spectrum disorders includes individuals with different ultimate aetiologies, even when biological or genetic markers are found they will not be present in all individuals with the phenotype. The fact that autism is not a unitary 'disorder' presents a significant challenge to genetic, biological, neurological and psychological research. Progress has recently been made in the earlier identification of autism both through screening programmes and by increased understanding and enhanced surveillance. This offers an opportunity to better understand the early developmental course of autism and may provide additional clues to the underlying pathology.

Autistic Disorder↗
PubMed2002

The prevalence of autism spectrum disorders. Recent evidence and future challenges.

BACKGROUND: Until recently best estimate prevalence rates for autism spectrum disorders (ASD) were 0.5/1,000 for autism and 2.0/1,000 for the broader spectrum. Three recent studies have suggested a significantly higher prevalence rate for ASD of 6.0/1,000 (mean 95 % CI = 4.8-8.0). METHOD: Possible determinants of the apparent increase in the prevalence of ASD are outlined. Methodological aspects of the three recent studies are examined. FINDINGS: Increased recognition, the broadening of the diagnostic concept over time and methodological differences across studies may account for most or all of the apparent increase in prevalence, although this cannot be quantified. CONCLUSIONS: Findings from ongoing studies should help confirm or disconfirm the putative rate of 6.0/1,000 for all ASD. The possibility that autism has been over-diagnosed in recent studies needs to be ruled out. Notwithstanding these outstanding questions, it appears likely that the current true prevalence of ASD is considerably greater than previously recognised. This has significant implications for our scientific understanding of ASD and for families and services. Future directions for epidemiological research are outlined.

Adolescent↗
PubMed2002

A pilot randomised control trial of a parent training intervention for pre-school children with autism. Preliminary findings and methodological challenges.

Few attempts have been made to conduct randomised control trials (RCTs) of interventions for pre-school children with autism. We report findings of a pilot RCT for a parent training intervention with a focus on the development of joint attention skills and joint action routines. Twenty-four children meeting ICD-10 criteria for childhood autism (mean age = 23 months) were identified using the CHAT screen and randomised to the parent training group or to local services only. A follow-up was conducted 12 months later (mean age = 35 months). There was some evidence that the parent training group made more progress in language development than the local services group. However, the present pilot study was compromised by several factors: a reliance on parental report to measure language, non-matching of the groups on initial IQ, and a lack of systematic checking regarding the implementation of the parent training intervention. Furthermore, three parents in the local services group commenced intensive, home-based behavioural intervention during the course of the study. The difficulties encountered in the conduct of RCTs for pre-school children with autism are discussed. Methodological challenges and strategies for future well-designed RCTs for autism interventions are highlighted.

Autistic Disorder↗
PubMed2002

Regression in individuals with Rett syndrome.

Data on features of regression and pre-regression developmental history in a case series of 53 girls and women with Rett syndrome are presented. Consistent with the diagnostic criteria, hand skills and verbal or non-verbal communication skills were the most common skills lost during regression. Play and motor skills were also lost in half the cases. Regression most commonly occurred between 12 and 18 months of age but was noted in a few cases before 6 months or after 36 months. Pre-regression developmental delays or abnormalities were noted in over two-thirds of cases, increasing to 85% of the youngest cases where parental reporting was likely to be more accurate. Age at regression was not associated with severity of physical and growth symptoms, and thus did not appear to be an index of neurological severity. There is a continuing need to further elucidate the pre- and post-regression features of Rett syndrome in order to aid early identification, diagnosis and referral for genotype mutation analysis.

Adolescent↗
PubMed2002

Follow-up of children with language delay and features of autism from preschool years to middle childhood.

Eighteen children (13 males, five females) who had severe developmental language delay/disorder and some features of autism (although insufficient in severity and combination to meet ICD-10 diagnostic criteria for childhood autism) at preschool age (Time 1; mean age 4 years 4 months) were followed up 4 years later (Time 2; mean age 8 years 7 months). At the initial assessment the diagnostic dilemma was how much the social communication impairments and behavioural problems were secondary to the language problem and how much they constituted a genuine case of a pervasive developmental disorder. It was anticipated that at follow-up some children would continue to show social impairments but that in others social impairments would have receded as language competence improved. Follow-up assessments included the Wechsler Intelligence Scale for Children, the Clinical Evaluation of Language Fundamentals, the Children's Communication Checklist, and the Social Communication Questionnaire. At follow-up, five children had continuing language disorder and were considered to fulfil diagnostic criteria for childhood autism, four children had continuing language disorder and met criteria for atypical autism, and nine met criteria for atypical autism but had somewhat recovered language skills. Thus, even in the subgroup of children whose language ability had improved the features of autism had not dissipated. Severity of social communication impairments and repetitive behaviours at Time 1, rated retrospectively from case notes, were associated with severity of autism symptoms and pragmatic competence at Time 2. The findings are discussed in relation to the unclear boundary between autism spectrum disorders and language delay/disorder.

Autistic Disorder↗
PubMed2002

Infants' behavioral reenactment of "failed attempts": exploring the roles of emulation learning, stimulus enhancement, and understanding of intentions.

Two studies were conducted to examine whether infants' reenactment of intended but unconsummated acts in A. N. Meltzoff's (1995) failed-attempt paradigm is due to reading the adult's underlying intention or to the effects of nonimitative social learning processes. Two novel conditions that emphasized the object affordances and the spatial contiguity of the object sets were devised. When infants' first actions only were counted, infants who observed the full-demonstration model produced more target acts. When all target acts produced within the 20-s response period were counted, infants in the emulation-learning and spatial contiguity conditions produced as many target acts as infants in the full-demonstration and failed-attempt conditions. This pattern of findings suggests that nonimitative social learning processes may influence infants' response in the behavioral reenactment paradigm.

Attention↗
PubMed2002

Practitioner review: Diagnosis of autism spectrum disorder in 2- and 3-year-old children.

BACKGROUND: Progress has recently been made in the earlier identification of children with autism spectrum disorder (ASD). Whilst being welcome, this progress to earlier referral and diagnosis presents new challenges to clinical practice, including the accuracy and stability of early diagnosis, the utility of standardised assessment instruments with young pre-schoolers and the ability to indicate prognosis. METHOD: A selective review of recent research literature on the characteristic features of ASD in preschool children. RESULTS: Multidisciplinary diagnostic assessment should include detailed information on developmental history, parents' descriptions of the everyday behaviour and activities of the child, direct assessment of the child's social interaction style, including where possible with age peers, and formal assessment of communicative, intellectual and adaptive function. Clinical assessments need to concentrate on the identification of impairments in early non-verbal social communication behaviours that characterise children with ASD from the second year of life, including social orienting, joint attention, imitation, play and reciprocal affective behaviour. The particular pattern of symptoms that presents in a 2-year-old with ASD may differ from that seen at the more prototypic age of 4 or 5 years. In particular, overt repetitive and stereotyped behaviours may be less notable, although where these are seen alongside the social and communicative impairments they are highly indicative of ASD. The use of standardised assessment instruments and the strict application of the DSM and ICD diagnostic criteria need to be employed with caution, as an expert clinical view has been shown to be more accurate. An important aspect of early diagnostic consultation is an open and straightforward approach to the negotiation of the diagnostic view with parents over time. CONCLUSIONS: Earlier diagnosis and rising recognition of ASD have significant implications for primary healthcare and specialist diagnostic and therapeutic services.

Autistic Disorder↗
PubMed2002

The Rett Syndrome Behaviour Questionnaire (RSBQ): refining the behavioural phenotype of Rett syndrome.

BACKGROUND: Although physical features, including loss of hand skills, deceleration of head growth, spasticity and scoliosis, are cardinal features of Rett syndrome (RS), a number of behavioural features are also associated with the disorder, including hand stereotypies, hyperventilation and breath holding. No study has tested the specificity of these behavioural features to individuals with RS, compared to individuals with severe to profound mental retardation (SMR). METHOD: A novel checklist of characteristic RS behavioural and emotional features, the Rett Syndrome Behaviour Questionnaire (RSBQ), was developed to test the type and specificity of behavioural features of RS against those found in girls with SMR. RESULTS: After controlling for the effects of RS-related physical disabilities, the RSBQ discriminated between the groups. Some aspects of the behaviours found to be specific to RS are included in the necessary or supportive RS diagnostic criteria, notably hand behaviours and breathing problems. Additional behavioural features were also more frequently reported in the RS than the SMR group, including mood fluctuations and signs of fear/anxiety, inconsolable crying and screaming at night, and repetitive mouth and tongue movements and grimacing. CONCLUSIONS: Full validation of the scale requires confirmation of its discriminatory power and reliability with independent samples of individuals with RS and SMR. Further delineation of the specific profile of behaviours seen in RS may help in identification of the function of the MECP2 gene and in improved differential diagnosis and management of individuals with RS.

Child↗
PubMedDate not supplied

Predicting language outcome in infants with autism and pervasive developmental disorder.

BACKGROUND: To examine longitudinal associations between diagnosis, joint attention, play and imitation abilities and language outcome in infants with autism and pervasive developmental disorder. METHODS AND PROCEDURES: Experimental measures of joint attention, play and imitation were conducted with a sample of infants with autism spectrum disorder at age 20 months. Language outcome was assessed at age 42 months. A within-group longitudinal correlational design was adopted. OUTCOMES AND RESULTS: Language at 42 months was higher for children with a diagnosis of pervasive developmental disorder than for children with a diagnosis of autism. Language at follow-up was also positively associated with performance on experimental measures of joint attention and imitation, but not with performance on experimental measures of play and 'goal detection' at 20 months, nor with a non-verbal intelligence quotient, although these associations were not examined independent of diagnosis. However, floor effects on the measure of play at 20 months and the small sample size limit the conclusions that can be drawn. CONCLUSIONS: Individual differences in infant social-communication abilities as well as diagnosis may predict language outcome in preschoolers with autism spectrum disorders. Attention should be directed at assessing these skills in 2- and 3-year-old children referred for a diagnosis of autism spectrum disorder. Imitation and joint attention abilities may be important targets for early intervention.

Attention↗