Distinct patterns of grey matter abnormality in high-functioning autism and Asperger's syndrome

Background: Autism exists across a wide spectrum and there is considerable debate as to whether children with Asperger’s syndrome, who have normal language milestones, should be considered to comprise a subgroup distinct other from high‐functioning children with autism (HFA), who have a history of delayed language development. Magnetic resonance imaging (MRI) studies of autism are in disagreement. One possible reason is that the diagnosis of autism takes precedence over Asperger’s syndrome and a distinction in language acquisition is rarely made. We therefore planned to examine a whole brain hypothesis that the patterns of grey matter differences in Asperger’s syndrome and HFA can be distinguished. Methods: We used voxel‐based computational morphometry to map grey matter volume differences in 33 children with either Asperger’s syndrome or high‐functioning autism compared to 55 typical developing control children balanced for age, IQ, gender, maternal language and ethnicity. Results: Children with HFA had significantly smaller grey matter volumes in subcortical, posterior cingulate and precuneus regions than the Asperger’s group. Compared to controls, children with HFA had smaller grey matter volumes in predominantly fronto‐pallidal regions, while children with Asperger’s had less grey matter in mainly bilateral caudate and left thalamus. In addition we found a significant negative correlation between the size of a grey matter cluster around BA44 language area and the age of acquisition of phrase speech in the children with HFA. When the groups were combined we confirmed a mixed picture of smaller grey matter volumes in frontal, basal ganglia, temporal and parietal regions. Conclusions: Our study suggests that the underlying neurobiology in HFA and Asperger’s syndrome is at least partly discrete. Future studies should therefore consider the history of language acquisition as a valuable tool to refine investigation of aetiological factors and management options in pervasive developmental disorders.     

Verbal bias in recognition of facial emotions in children with Asperger syndrome

Thirteen children and adolescents with diagnoses of Asperger syndrome (AS) were matched with 13 nonautistic control children on chronological age and verbal IQ. They were tested on their ability to recognize simple facial emotions, as well as facial emotions paired with matching, mismatching, or irrelevant verbal labels. There were no differences between the groups at recognizing simple emotions but the Asperger group performed significantly worse than the control group at recognizing emotions when faces were paired with mismatching words (but not with matching or irrelevant words). The results suggest that there are qualitative differences from nonclinical populations in how children with AS process facial expressions. When presented with a more demanding affective processing task, individuals with AS showed a bias towards visual-verbal over visual-affective information (i.e., words over faces). Thus, children with AS may be utilizing compensatory strategies, such as verbal mediation, to process facial expressions of emotion.     

Emanuel Miller lecture: confusions and controversies about Asperger syndrome

BACKGROUND: Hans Asperger drew attention to individuals who show the core symptoms of autism in the presence of high verbal intelligence. METHODS: A review of the literature explores current issues concerning the diagnosis and nature of Asperger syndrome. RESULTS: The behavioural and neurophysiological evidence to date suggests that Asperger syndrome is a variant of autism typically occurring in high-functioning individuals, and not a separate disorder. One of the problems of diagnosis is that the typical impairment of social communication may be difficult to identify in early childhood, and can be camouflaged in adulthood by compensatory learning. The range and nature of the social impairments in Asperger syndrome are still in need of investigation, but appear to be less severe than in autism. Experimental evidence suggests that individuals with Asperger syndrome may lack an intuitive theory of mind (mentalising), but may be able to acquire an explicit theory of mind. Brain imaging studies pinpoint a network that links medial prefrontal and temporal cortex as the neural substrate of intuitive mentalising. This network shows reduced activation and poor connectivity in Asperger syndrome. While some individuals with Asperger syndrome have written eloquently about their lives, their ability to talk about their own emotions appears to be impaired (alexithymia). This impairment may be linked to depression and anxiety, which is common in adulthood. Little is as yet known about the often considerable cognitive strengths in Asperger syndrome, or about the difficulties observed in higher-level executive skills. CONCLUSIONS: Studies are needed that define the developmental course of the disorder and the nature of the strengths and weaknesses in both social and non-social domains. This requires more sensitive assessment instruments than are currently available. Questions about the prevalence of Asperger syndrome, about associated and secondary features, and about optimal education and management, urgently call for such studies.     

The Epidemiology of Asperger Syndrome

Abstract— This paper describes a total population study of Asperger syndrome using a two-stage procedure. All school children in an outer Goteborg borough were screened. Final case selection based on clinical work-up showed a minimum prevalence of 3 6 per 1.000 children (7–16 years of age) using Gillberg and Gillberg's criteria and a male to female ratio of 4.1 Including suspected and possible Asperger syndrome cases, the prevalence rose to 7.1 per 1 000 children and the male:female ratio dropped to 2.3:1. These findings are discussed as they relate to previously published results in the field and to findings obtained using Szatmari et al .'s and ICD-10 draft criteria for the disorder     

Similar developmental trajectories in autism and Asperger syndrome: from early childhood to adolescence

Objective:  The objective of this study was to chart the developmental trajectories of high-functioning children with autism spectrum disorders (ASD) from early childhood to adolescence using the presence and absence of structural language impairment (StrLI) as a way of differentiating autism from Asperger syndrome (AS).
Method:  Sixty-four high-functioning children with ASD were ascertained at 4–6 years of age from several different regional diagnostic and treatment centers. At 6–8 years of age, the ADI-R and the Test of Oral Language Development were used to define an autism group (those with StrLI at 6–8 years of age) and an AS group (those without StrLI). Growth curve analysis was then used to chart the developmental trajectories of these children on measures of autistic symptoms, and adaptive skills in communication, daily living and socialization.
Results:  Differentiating the ASD group in terms of the presence/absence of StrLI provided a better explanation of the variation in growth curves than not differentiating high-functioning ASD children. The two groups had similar developmental trajectories but the group without StrLI (the AS group) was functioning better and had fewer autistic symptoms than the group with StrLI (the autism group) on all measures across time. The differences in outcome could not be explained by non-verbal IQ or change in early language skills.
Conclusion:  Distinguishing between autism and Asperger syndrome based on the presence or absence of StrLI appears to be a clinically useful way of classifying ASD sub-types.     

Eye-witness memory and suggestibility in children with Asperger syndrome

BACKGROUND: Individuals with autism spectrum disorders (ASD) present with a particular profile of memory deficits, executive dysfunction and impaired social interaction that may raise concerns about their recall and reliability in forensic and legal contexts. Extant studies of memory shed limited light on this issue as they involved either laboratory-based tasks or protocols that varied between participants. METHOD: The current study used a live classroom event to investigate eye-witness recall and suggestibility in children with Asperger syndrome (AS group; N = 24) and typically developing children (TD group; N = 27). All participants were aged between 11 and 14 years and were interviewed using a structured protocol. Two measures of executive functioning were also administered. RESULTS: The AS group were found to be no more suggestible and no less accurate than their peers. However, free recall elicited less information, including gist, in the AS group. TD, but not AS, participants tended to focus on the socially salient aspects of the scene in their free recall. Both general and specific questioning elicited similar numbers of new details in both groups. Significant correlations were found between memory recall and executive functioning performance in the AS group only. CONCLUSIONS: The present study indicates that children with AS can act as reliable witnesses but they may be more reliant on questioning to facilitate recall. Our findings also provide evidence for poor gist memory. It is speculated that such differences stem from weak central coherence and lead to a reliance on generic cognitive processes, such as executive functions, during recall. Future studies are required to investigate possible differences in compliance, rates of forgetting and false memory.     

Prevalence of Overweight and Obesity in a Large Clinical Sample of Children With Autism

BackgroundOverweight and obesity are major pediatric public health problems in the United States; however, limited data exist on the prevalence and correlates of overnutrition in children with autism.MethodsThrough a large integrated health care system's patient database, we identified 6672 children ages 2 to 20 years with an assigned ICD-9 code of autism (299.0), Asperger syndrome (299.8), and control subjects from 2008 to 2011 who had at least 1 weight and height recorded in the same visit. We calculated age-adjusted, sex-adjusted body mass index and classified children as overweight (body mass index 85th to 95th percentile) or obese (≥95th percentile). We used multinomial logistic regression to compare the odds of overweight and obesity between groups. We then used logistic regression to evaluate factors associated with overweight and obesity in children with autism, including demographic and clinical characteristics.ResultsCompared to control subjects, children with autism and Asperger syndrome had significantly higher odds of overweight (odds ratio, 95% confidence interval: autism 2.24, 1.74–2.88; Asperger syndrome 1.49, 1.12–1.97) and obesity (autism 4.83, 3.85–6.06; Asperger syndrome 5.69, 4.50–7.21). Among children with autism, we found a higher odds of obesity in older children (aged 12–15 years 1.87, 1.33–2.63; aged 16–20 years 1.94, 1.39–2.71) compared to children aged 6 to 11 years. We also found higher odds of overweight and obesity in those with public insurance (overweight 1.54, 1.25–1.89; obese 1.16, 1.02–1.40) and with co-occurring sleep disorder (obese 1.23, 1.00–1.53).ConclusionsChildren with autism and Asperger syndrome had significantly higher odds of overweight and obesity than control subjects. Older age, public insurance, and co-occurring sleep disorder were associated with overweight or obesity in this population.     

The severity and nature of motor impairment in Asperger's syndrome: a comparison with specific developmental disorder of motor function

BACKGROUND: The aims of this study were to measure objectively the extent and severity of motor impairment in children with Asperger's syndrome and to determine whether the motor difficulties experienced by such children differed in any way from those classified as having a Specific Developmental Disorder of Motor Function (SDD-MF). Criteria derived from ICD 10-R were used to identify 11 children with Asperger's syndrome and a matched group of 9 children with a Specific Developmental Disorder of Motor Function. Children in both groups were required to have a verbal IQ of 80 or greater on the WISC IIIR. METHOD: The Autism Diagnostic Interview (Revised; Lord, Rutter, & LeCouteur, 1994) was used to identify features of AS in the first group and to exclude them in the latter. The Movement Assessment Battery for Children (Henderson & Sugden, 1992) provided a standardised test of motor impairment. A Gesture Test based on that by Cermak, Coster, and Drake (1980) was used to assess the child's ability to mime the use of familiar tools and to imitate meaningless sequences of movements. RESULTS: All the children with Asperger's syndrome turned out to meet our criterion for a diagnosis of motor impairment, five of the six most severely motor impaired children in the whole study being from this group. Performance of the Asperger group was also slightly poorer on the Gesture Test. The profile of performance on each test was examined in detail but no evidence of group differences in the pattern of impairment was found. CONCLUSIONS: This study is consistent with others suggesting a high prevalence of clumsiness in Asperger's syndrome. Our findings also attest to the widespread prevalence of motor impairment in developmental disorders and the problems such co-morbidity poses for attempts to posit discrete and functionally coherent impairments underlying distinct syndromes.     

A new 'advanced' test of theory of mind: evidence from children and adolescents with Asperger syndrome

BACKGROUND: The aim of the present study was to assess the ability of children and adolescents with Asperger syndrome (AS) (N = 21) to infer physical versus mental states on a new 'advanced' test of theory-of-mind - Stories from Everyday Life. The participants in the AS group were of normal intelligence and were compared with an age-matched control group (N = 20) of normally developing children and adolescents. METHOD: The test materials comprised 26 short stories or 13 pairs of different types of stories. This contextually complex theory-of-mind battery aimed to record the participants' ability to make inferences about physical as well as mental states. The first part of each story described a physical or mechanical event, and a test question then tested the participants' ability to make an inference about a physical state. The last part of the stories contained two questions, testing the ability to infer a mental state from the story context, e.g., understanding social communication such as a lie, white lie, figure of speech, misunderstanding, double bluff, irony, persuasion, contrary emotions, forgetting, jealousy, intentions, empathy and social blunders. The participants' reaction time and number of prompt questions were also recorded. RESULTS: The participants in the AS group showed significantly more problems attributing mental state inferences relative to the control group. They performed considerably better on tasks involving a physical state, but still did less well than the controls. They had a tendency to interpret behaviour and utterances literally, without regard to context, and to choose a physical explanation when a mental state answer was more appropriate. They also needed significantly more prompt questions and used significantly more time than the controls to solve the tasks, especially those involving mental state inference. CONCLUSIONS: This study supports earlier findings that individuals with AS/HFA have difficulties attributing mental states in context, but seem to have significantly fewer difficulties inferring physical states. The fact that the clinical group also used significant longer reaction time and needed significantly more prompt questions to solve the tasks relative to the control group may also be related to their problems in understanding mental states. However, the possibility remains that these difficulties could represent a separate factor - or a distinct 'cognitive style'- suggesting that at least some individuals with AS may be generally slow in solving cognitive tasks.     

Working memory in children and adolescents with Down syndrome: evidence from a colour memory experiment

BACKGROUND: This paper reports information on the visual and verbal short-term memory of individuals with Down syndrome. METHODS: Colour memory in 16 children and adolescents with Down syndrome was compared with that of 16 typically developing children matched for receptive vocabulary. It was suggested that focal colours should be remembered more successfully than non-focal colours on the basis that the former could be remembered using a verbal recoding strategy. However, children with Down syndrome, for whom a deficit in verbal short-term memory makes the use of such a strategy unlikely, should remember focal and non-focal colours equally well. More importantly, if individuals with Down syndrome have more developed visual memory abilities than control children, they should outperform them in recognising non-focal colours. RESULTS: Although the group with Down syndrome demonstrated significantly better Corsi blocks performance than controls, and displayed similar levels of colour knowledge, no advantage for colour memory was found. Non-focal colours were remembered by individuals with Down syndrome as successfully as focal colours but there was no indication of a visual memory advantage over controls. Focal colours were remembered significantly more successfully than non-focal colours by the typically developing children. CONCLUSION: Their focal colour memory was significantly related to digit span, but only Corsi span was related to focal colour memory in the group with Down syndrome.     

Predictors of outcome among high functioning children with autism and Asperger syndrome

BACKGROUND: The objective of this paper is to assess the extent to which measures of cognitive abilities taken in an inception cohort of young high functioning children with autism and Asperger syndrome predict outcome roughly two and six years later. METHOD: Children who received a diagnosis of autism or Asperger syndrome (AS) and who had a nonverbal IQ score in the 'non-retarded' range were included in the inception cohort. Measures of language and nonverbal skills were taken when the children were 4-6 years of age and outcome assessments were completed when the children were 6-8 and 10-13 years of age. The three outcome measures consisted of scales of adaptive behaviours in socialisation and communication and a composite measure of autistic symptoms (abnormal language, abnormal body and object use, difficulties relating to others, sensory issues and social and self-help difficulties). RESULTS: The explanatory power of the predictor variables was greater for communication and social skills than for autistic symptoms. The power of prediction was stable over time but did differ by PDD subtype. In general, the association between language skills and outcome was stronger in the autism group than in the AS group. CONCLUSIONS: These results support the emphasis of early intervention programmes on language but more work needs to be done on understanding variables that influence outcome in social skills and autistic behaviours, particularly in those with AS.     

Autism and developmental receptive language disorder--a follow-up comparison in early adult life. II: Social, behavioural, and psychiatric outcomes

This paper focuses on general social functioning in two groups of young men, one with autism and one with developmental receptive language disorders, who were first assessed at the ages of 7-8 years. At that time, although matched for nonverbal IQ (mean 92-93) and expressive language, the Language group showed significantly fewer social and behavioural problems. At follow-up, when aged on average, 23 to 24 years, the Autism group continued to show significantly more impairments in terms of stereotyped behaviour patterns, social relationships, jobs, and independence. However, problems in all these areas were also common in the Language group. Many still lived with their parents, few had close friends or permanent jobs, and ratings of social interaction indicated abnormalities in a number of different areas. On a composite measure of social competence only 10% of the Language group was assessed as having severe social difficulties compared to 74% of the Autism group. Nevertheless, 65% were rated as having moderate social problems and only 25% were rated as being of near/normal social functioning. Two individuals in the Language group, but none in the Autism group, had also developed a florid paranoid psychosis in late adolescence. As in the follow-up of cognitive and linguistic functioning (see Mawhood et al., 2000, this volume, pp. 547-559), discriminant function analysis, which had clearly distinguished between the groups as children, now showed much greater overlap between them. Regression analysis indicated that although early language ability appeared to be related to outcome in the Autism group, there was little association between any measures of childhood functioning and prognosis in the Language group. Theoretically, these findings have implications for our understanding of the nature of autism and other pervasive language disorders, and of the relationship between them. Practically, they demonstrate the very persistent problems experienced by individuals with developmental language disorders, and their need for much greater help and support than is presently available.     

Symptoms of presentation in hyperactive and clinic children

Symptoms of presentation at a child psychiatric clinic were compared in a group of 100 children described as hyperactive and a similarly aged group of 229 children referred to the clinic for the full range of child psychiatric problems.
The hyperactive children showed significantly more speech problems, sleep problems and nightmares, and management problems and temper tantrums than the clinic group. These problems presented more frequently in boys.
Depression, headache and abdominal pain occurred at an older age in the full clinic group of children, who came significantly more often from single families.     

Another Advanced Test of Theory of Mind: Evidence from Very High Functioning Adults with Autism or Asperger Syndrome

Previous studies have found a subgroup of people with autism or Asperger Syndrome who pass second-order tests of theory of mind. However, such tests have a ceiling in developmental terms corresponding to a mental age of about 6 years. It is therefore impossible to say if such individuals are intact or impaired in their theory of mind skills. We report the performance of very high functioning adults with autism or Asperger Syndrome on an adult test of theory of mind ability. The task involved inferring the mental state of a person just from the information in photographs of a person's eyes. Relative to age-matched normal controls and a clinical control group (adults with Tourette Syndrome), the group with autism and Asperger Syndrome were significantly impaired on this task. The autism and Asperger Syndrome sample was also impaired on Happe's strange stories tasks. In contrast, they were unimpaired on two control tasks: recognising gender from the eye region of the face, and recognising basic emotions from the whole face. This provides evidence for subtle mindreading deficits in very high functioning individuals on the autistic continuum.     

"Theory of Mind" in Asperger''s Syndrome Dermot M. Bowler

Two studies are reported in which the ability of people with Asperger's syndrome to understand problems of the type "Peter thinks that Jane thinks that ..." tested. The results showed that in contrast to younger or more handicapped autistic individuals, Asperger subjects were able to solve problems of the type just outlined, i.e. that they possessed a second-order theory of mind. When asked to explain their solutions however, they typically did not use mental state terms but did not differ in this respect either from non-handicapped or socially impaired, chronic schizophrenic controls. The implications of the results for current cognitive theories of autistic impairment are discussed.     

Asperger syndrome in childhood: review of four cases]

INTRODUCTION: Asperger syndrome is a pervasive developmental disorder included lately in the international classifications. OBSERVATIONS: We report the observations of four children presenting this syndrome. For every patient, we collected antecedents and psychomotor development; we made neuropsychological assessment and video recording. Three patients underwent an EEG and one a cerebral MRI. RESULTS: These patients were between ten- and sixteen-year old. The neuropsychological assessment showed a heterogeneous intellectual functioning with three times out of four a dissociation between high verbal level and low non-verbal level. Their language appeared sophisticated, apragmatic, their comprehension was inflexible. The mean age at diagnosis was ten years. They showed a sociability and autonomy improvement but they were conscious of their difference and suffered from it. CONCLUSION: Our four cases allow to present Asperger syndrome, slightly known in France. Collaborative studies and genetic studies are necessary to improve the knowledge of this syndrome.     

Effect of growth hormone therapy on feeding problems and food intake in children with growth disorders

To assess the effect of therapeutic doses of growth hormone (GH) on the feeding problems, food intake, body fat and mealtime interactions of children with growth disorders, an age-matched group of 46 children with Turner syndrome (TS) or Silver Russell syndrome (SRS) was examined using questionnaire measures and direct observation. The children's body fat was measured using bio-electrical impedance analysis and skinfold thickness measurements. Children receiving GH consumed significantly more energy, protein, fat and carbohydrate than did the children who were not receiving GH, independent of the extent of the child's feeding problems. Children receiving GH had less body fat than did children who were not receiving GH. Children who were not receiving GH distracted their parents from the mealtime significantly more often and received more negative prompting and coaxing from their parents to eat than did children who were receiving GH. This study provides evidence to support the theory that appetite and intake is determined in part by growth and growth potential. Feeding problems seen in children with growth disorders are partly due to parental attempts to impose control over their child's intake, when their child consumes less than the parent believes to be adequate. Conclusion: GH has a significant impact on both the food intake and parent-child interaction at mealtimes of children with SRS and TS.     

Development and current functioning in adolescents with Asperger syndrome: a comparative study

Adolescents with Asperger syndrome (AS: without delay in speech development, diagnosed according to ICD-10 clinical criteria) were compared with a group with high-functioning autism (HFA: all with delayed speech development), and a group with conduct disorder (CD). Family and genetic studies suggest that Asperger syndrome and autism form part of the same spectrum, whereas the social impairments in conduct disorder are assumed to have different origins. The aims were to explore the relationships between early speech development and other aspects of functioning in autistic disorders, and to compare autistic and nonautistic social impairments. Early and current behaviour and IQ profiles were investigated. The CD group were clearly different from both the AS and HFA groups. The AS group tended to have less severe early behavioural abnormalities than the HFA group, and were unlikely to have speech abnormalities, but other communicative, social, and restricted/ stereotyped behavioural difficulties were largely of a similar pattern to the abnormalities in the HFA group. Eighty per cent of the AS group met criteria for autism on the diagnostic algorithm associated with the Autism Diagnostic Interview-Revised. By adolescence, the AS group were reported to be as abnormal as the HFA group but in structured 1:1 interaction their conversation was better. IQ profile in the AS group showed relative strength on verbal measures, unlike the HFA group, but relatively good performance on the Block Design subtest of the WISC/WAIS was a feature of both the AS and HFA groups. The results indicate closely similar behavioural manifestations may arise by adolescence despite differences in speech development. Follow-up studies and further family investigations will be required to clarify the origins of these and other patterns of autistic development.     

"Motor" impairment in Asperger syndrome: evidence for a deficit in proprioception

Motor impairment has frequently been described in Asperger syndrome (AS), a pervasive developmental disorder included in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV). Previous research focusing on this motor dysfunction has yielded inconsistent results, and the "clumsiness" observed clinically remains poorly defined. To clarify further the issue of motor impairment, we compared a group of 10 children and young adults who met DSM-IV criteria for AS with a control group with no neurological impairment. Subjects were matched on age, sex, socioeconomic status, and Verbal IQ. A broad battery of motoric tests was administered. Subjects with AS were found to perform more poorly than controls on tests of apraxia, one-leg balance with eyes closed, tandem gait, and repetitive finger-thumb apposition. No significant differences were found on tests of finger tapping, grooved pegboard, trail making, or visual-motor integration. The pattern of impairments suggests that a proprioceptive deficit may underlie the incoordination observed in AS and that these individuals may be overreliant on visual input to maintain balance and position in space.     

A multi-component social skills intervention for children with Asperger syndrome: the Junior Detective Training Program

Background:  The study aimed to investigate the effectiveness of a new multi-component social skills intervention for children with Asperger syndrome (AS): The Junior Detective Training Program. This 7-week program included a computer game, small group sessions, parent training sessions and teacher handouts.
Method:  Forty-nine children with AS were recruited to participate and randomly assigned to intervention ( n  =   26) or wait-list control ( n  =   23) conditions.
Results:  Relative to children in the wait-list group, program participants showed greater improvements in social skills over the course of the intervention, as indicated by parent-report measures. Teacher-report data also confirmed that children receiving the intervention made significant improvements in social functioning from pre- to post-treatment. Treatment group participants were better able to suggest appropriate emotion-management strategies for story characters at post-intervention than at pre-intervention, whereas control participants were not. However, there was no difference in the improvements made by children in the intervention and control conditions on facial expression and body-posture recognition measures. Follow-up data suggested that treatment gains were maintained by children at 5-months post-intervention.
Conclusions:  The Junior Detective Training Program appeared to be effective in enhancing the social skills and emotional understanding of children with AS. Limitations and suggestions for future research are discussed.