Autism and diagnostic substitution: evidence from a study of adults with a history of developmental language disorder

Rates of diagnosis of autism have risen since 1980, raising the question of whether some children who previously had other diagnoses are now being diagnosed with autism. We applied contemporary diagnostic criteria for autism to adults with a history of developmental language disorder, to discover whether diagnostic substitution has taken place. A total of 38 adults (aged 15–31y; 31 males, seven females) who had participated in studies of developmental language disorder during childhood were given the Autism Diagnostic Observation Schedule - Generic. Their parents completed the Autism Diagnostic Interview - Revised, which relies largely on symptoms present at age 4 to 5 years to diagnose autism. Eight individuals met criteria for autism on both instruments, and a further four met criteria for milder forms of autistic spectrum disorder. Most individuals with autism had been identified with pragmatic impairments in childhood. Some children who would nowadays be diagnosed unambiguously with autistic disorder had been diagnosed with developmental language disorder in the past. This finding has implications for our understanding of the epidemiology of autism.     

Correlates of head circumference growth in infants later diagnosed with autism spectrum disorders

Previous research has demonstrated that children diagnosed with autism spectrum disorder show an abnormal acceleration of head growth during the first year of life. This study attempts to replicate these findings and to determine whether overgrowth is associated with clinical outcome. Measurements of head circumference, body length, and body weight taken during the first 2 years of life were obtained from a sample of 35 children diagnosed with autism spectrum disorder and compared to both national normative data (Centers for Disease Control and Prevention) and a control group of 37 healthy infants. Results demonstrated that compared to national averages, infants who were later diagnosed with autism spectrum disorder had a significantly smaller head circumference at birth to 2 weeks and a significantly larger head circumference by 10 to 14 months. Children with autism spectrum disorder were also significantly longer and heavier beginning at 1 to 2 months. However, when overall length and weight were controlled, head circumference was not bigger in the autistic spectrum disorder group compared to local controls. Correlations between head circumference and clinical outcome were significant for 5 of the 30 clinical variables that were run, suggesting that there appears to be no simple or straightforward relationship between head circumference and clinical outcome. Smaller head circumference at birth to 2 weeks was associated with a greater number of symptoms related to social impairment and a greater total number of autism spectrum disorder symptoms based on the Diagnostic and Statistical Manual of Mental Disorders , Fourth Edition criteria. Larger head circumference at 15 to 25 months was also associated with a greater number of symptoms of social impairment. In addition, greater head circumference change during the first 2 years was associated with poorer performance on the visual reception subtest of the Mullen Scales of Early Learning and a smaller number of stereotyped and repetitive behaviors and interests based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. These findings support previous findings of accelerated brain growth during the first year of life in autism spectrum disorder and question whether growth factors might contribute to both accelerated brain growth and overall body growth.     

Autism in immigrants: a population-based study from Swedish rural and urban areas

In a population study, 55 children aged 13 years and under were diagnosed as suffering from autistic disorder according to DSM-III-R criteria. Fifteen of these children (27%) were born to parents, at least one of whom had migrated to Sweden. These 15 cases were analysed in some detail with a view to finding possible background factors that could account for the relatively high prevalence of autism among some immigrant populations. In a few cases, autism or Asperger syndrome had been diagnosed in a native Swedish parent who went abroad in order to find a spouse. In several other cases, the child was the first child born in Sweden after the mother had moved there. The contribution of genetic and other prenatal factors to autism in immigrant populations is discussed.     

Autism in immigrants: children born in Sweden to mothers born in Uganda

Three boys diagnosed as suffering from autistic disorder were born in Sweden to mothers born in Uganda. Two were related but the third boy was unrelated to the others. The prevalence for autistic disorder in Goteborg children born to mothers who were born in Uganda was 15% which is almost 200 times higher than in the general population of children. The possible reason for the high autism rate in this particular ethnic subgroup is discussed.     

Chromosomal Abnormalities in a Series of Children with Autistic Disorder

In a series of 127 children diagnosed with autistic disorder the karyotypes of 8, on whom data were available, showed the following chromosomal abnormalities: breakage, a 47 XY pattern, trisomy 13, inversion-duplication of chromosome 15, 47 XY, +der (15) (pter q15: p11 pter), 47 XXY and 46 XY, inv (2) (p11:q13pat, 3q+). Compared to those who were not karyotyped or had normal karyotypes, the children with abnormalities, although cognitively more delayed, were not rated as more severely autistic. Facial dysmorphias and minor physical anomalies tended to be more frequent in the chromosomally deviant subgroup. No differences in demographic characteristics or parental ages were evident. Results are consistent with the view of variability of expression of marker chromosome deviations and a greater severity of retardation and symptoms of autism in those affected. The relevance of the findings to a multimodal genetic etiology of autistic disorder is discussed.     

Neuropsychiatric Assessmenit of Children with Autism: A Population-Based Study

Thirty-five children with autistic disorder and 17 with autistic-like conditions underwent an exhaustive neurobiological evaluation, and the findings were contrasted with those obtained from various comparison groups. Almost 90 per cent of the children with autistic disorder and autistic-like conditions had major indications of brain damage or dysfunction. Some of those who did not show such abnormalities had a first-degree relative with Asperger syndrome. The rate of abnormality was similar to that of severely mentally retarded children, but in excess of that of normal children. Within the autism group, abnormality rate did not correlate with degree of mental retardation. It is concluded that autism has multiple biological aetiologies and that autistic symptoms in a child should always prompt a thorough medical/neurobiological evaluation.     

Sensory abnormalities in autism: A brief report

Sensory abnormalities were assessed in a population-based group of 208 20-54-month-old children, diagnosed with autism spectrum disorder (ASD) and referred to a specialized habilitation centre for early intervention. The children were subgrouped based upon degree of autistic symptoms and cognitive level by a research team at the centre. Parents were interviewed systematically about any abnormal sensory reactions in the child. In the whole group, pain and hearing were the most commonly affected modalities. Children in the most typical autism subgroup (nuclear autism with no learning disability) had the highest number of affected modalities. The children who were classified in an “autistic features” subgroup had the lowest number of affected modalities. There were no group differences in number of affected sensory modalities between groups of different cognitive levels or level of expressive speech. The findings provide support for the notion that sensory abnormality is very common in young children with autism. This symptom has been proposed for inclusion among the diagnostic criteria for ASD in the upcoming DSM-V.     

Sensory abnormalities in autism. A brief report

Sensory abnormalities were assessed in a population-based group of 208 20-54-month-old children, diagnosed with autism spectrum disorder (ASD) and referred to a specialized habilitation centre for early intervention. The children were subgrouped based upon degree of autistic symptoms and cognitive level by a research team at the centre. Parents were interviewed systematically about any abnormal sensory reactions in the child. In the whole group, pain and hearing were the most commonly affected modalities. Children in the most typical autism subgroup (nuclear autism with no learning disability) had the highest number of affected modalities. The children who were classified in an "autistic features" subgroup had the lowest number of affected modalities. There were no group differences in number of affected sensory modalities between groups of different cognitive levels or level of expressive speech. The findings provide support for the notion that sensory abnormality is very common in young children with autism. This symptom has been proposed for inclusion among the diagnostic criteria for ASD in the upcoming DSM-V.     

Investigating gender differences in the early markers of Autism Spectrum Conditions (ASC) in infants and toddlers

BackgroundMany females with Autism Spectrum Conditions (ASC) are diagnosed later, mis-diagnosed, or missed altogether compared with males, leading to lost opportunities for early supports and services. It is therefore critical that researchers attempt to identify the earliest possible opportunity for females with ASC to be identified and diagnosed. The primary objective of this study was to investigate gender differences in the early signs of ASC in infants and toddlers identified during routine, community-based, developmental surveillance. A secondary aim was to examine gender ratio trends across time.MethodA cross-sectional sample of 197 infants and toddlers (44 female, 153 male) at “high likelihood” for ASC were grouped by autism diagnosis and gender to enable social-communication behaviours to be compared at 18 and 24 months of age. Furthermore, gender ratio trends were examined between 12 and 24 months of age.ResultsNo gender differences were found across groups at 18–24-months (small samples prohibited analyses at 12-months). However, the ratio of autistic females to males decreased from 1:15 at 12-months to 1:3.2 by 24-months.ConclusionsThe results of this study suggest close monitoring of females is required when conducting developmental surveillance for ASC, due to the large gender ratio discrepancy between 12- and 24-months. It is recommended that future studies continue to focus on the early autism phenotype in community-based samples, to assist with modification or development of female specific screening and developmental surveillance tools during infancy and toddlerhood.     

Does Gender Matter? A One Year Follow-up of Autistic,Attention and Anxiety Symptoms in High-Functioning Children with Autism Spectrum Disorder

Gender differences in autism spectrum disorder (ASD) symptoms and associated problem behaviours over development may provide clues regarding why more males than females are diagnosed with ASD. Fifty-six high-functioning children with ASD, and 44 typically developing controls, half of the participants female, were assessed at baseline (aged 7–12 years) and one-year later, collecting measures of autism, attention and anxiety symptoms, school placement and support information. Findings indicated no gender differences in autistic symptoms. Males were more hyperactive and received more integration-aide support in mainstream schools, and females were more socially anxious. Overall, similar gender profiles were present across two time points. Lower hyperactivity levels in females might contribute to their under-identification. Implications are discussed using a biopsychosocial model of gender difference.     

Hippocampus and amygdala volumes in parents of children with autistic disorder

OBJECTIVE: Structural and functional abnormalities in the medial temporal lobe, particularly the hippocampus and amygdala, have been described in people with autism. The authors hypothesized that parents of children with a diagnosis of autistic disorder would show similar changes in these structures. METHOD: Magnetic resonance imaging scans were performed in 17 biological parents of children with a diagnosis of DSM-IV autistic disorder. The scans were compared with scans from 15 adults with autistic disorder and 17 age-matched comparison subjects with no personal or familial history of autism. The volumes of the hippocampus, amygdala, and total brain were measured in all participants. RESULTS: The volume of the left hippocampus was larger in both the parents of children with autistic disorder and the adults with autistic disorder, relative to the comparison subjects. The hippocampus was significantly larger in the adults with autistic disorder than in the parents of children with autistic disorder. The left amygdala was smaller in the adults with autistic disorder, relative to the other two groups. No differences in total brain volume were observed between the three groups. CONCLUSIONS: The finding of larger hippocampal volume in autism is suggestive of abnormal early neurodevelopmental processes but is partly consistent with only one prior study and contradicts the findings of several others. The finding of larger hippocampal volume for the parental group suggests a potential genetic basis for hippocampal abnormalities in autism.     

Seen but not heard: School-based professionals’ oversight of autism in children from ethnic minority groups

Previous studies have shown that ethnic background hinders clinician detection of autistic features in children from non-western minority groups. The use of a structured instrument during evaluation of these children can reduce the risk of hindered detection. The aims of the current studies were to establish the extent of school-based professionals’ involvement in detecting autism and to replicate earlier findings of autism detection amongst school mentors. Results showed that school-based professionals were reported to be the first to suspect autistic features in 20% of children later diagnosed with autism. Additionally, school-based professionals refer to autism more often when judging children from majority than children from minority groups. However, using a structured instrument did not eliminate this bias. Providing these professionals with culture-sensitive education may help maximise their involvement in detecting autism amongst children from all ethnic backgrounds.     

Behavioral manifestations of autism in the first year of life

In the interest of more systematically documenting the early signs of autism, and of testing specific hypotheses regarding their underlying neurodevelopmental substrates, we have initiated a longitudinal study of high-risk infants, all of whom have an older sibling diagnosed with an autistic spectrum disorder. Our sample currently includes 150 infant siblings, including 65 who have been followed to age 24 months, who are the focus of this paper. We have also followed a comparison group of low-risk infants. Our measures include a novel observational scale (the first, to our knowledge, that is designed to assess autism-specific behavior in infants), a computerized visual orienting task, and standardized measures of temperament, cognitive and language development. Our preliminary results indicate that by 12 months of age, siblings who are later diagnosed with autism may be distinguished from other siblings and low-risk controls on the basis of: (1) several specific behavioral markers, including atypicalities in eye contact, visual tracking, disengagement of visual attention, orienting to name, imitation, social smiling, reactivity, social interest and affect, and sensory-oriented behaviors; (2) prolonged latency to disengage visual attention; (3) a characteristic pattern of early temperament, with marked passivity and decreased activity level at 6 months, followed by extreme distress reactions, a tendency to fixate on particular objects in the environment, and decreased expression of positive affect by 12 months; and (4) delayed expressive and receptive language. We discuss these findings in the context of various neural networks thought to underlie neurodevelopmental abnormalities in autism, including poor visual orienting. Over time, as we are able to prospectively study larger numbers and to examine interrelationships among both early-developing behaviors and biological indices of interest, we hope this work will advance current understanding of the neurodevelopmental origins of autism.     

Effect of secretin on children with autism: a randomized controlled trial

To determine the effect of intravenous porcine secretin on autistic behaviours in children aged 2 to 7 years, the effects of secretin on (1) performance on a standardized language measure, and (2) autistic behaviours, as rated by parents and child development professionals was examined. Employing a randomized, double-blind, placebo-controlled design, 95 participants were assigned to one of two groups and administered a single dose of either secretin or placebo. A follow-up assessment was conducted 3 weeks after the injection. No significant differences in language or autistic behaviour measures were observed at the 3-week follow-up between the groups. Also, there was no significant difference in the proportion of individuals who improved by > or = 6 points on the language measure at follow-up. This study showed no significant effects of secretin on children with autism. Our results are consistent with a systematic review of randomized controlled trials evaluating the effect of secretin in children with autism.     

Stereotyped Motor Behaviors Associated with Autism in High-risk Infants: A Pilot Videotape Analysis of a Sibling Sample

This study examined motor behaviors in a longitudinal cohort of infant siblings of children with autism. Stereotypic movements and postures occurring during standardized observational assessments at 12 and 18 months were coded from videotapes. Participants included eight infant siblings later diagnosed with autism spectrum disorder (ASD), a random sample of nine non-diagnosed siblings, and 15 controls. Videos were coded blind to diagnostic group. At 12 and 18 months the ASD group “arm waved” more frequently and at 18 months, one posture (“hands to ears”) was more frequently observed in the ASD and non-diagnosed group compared to the controls. Overall, the siblings subsequently diagnosed with ASD and the comparison groups had considerable overlap in their repertoires of stereotyped behaviors.     

Gross Motor Development,Movement Abnormalities,and Early Identification of Autism

Gross motor development (supine, prone, rolling, sitting, crawling, walking) and movement abnormalities were examined in the home videos of infants later diagnosed with autism (regression and no regression subgroups), developmental delays (DD), or typical development. Group differences in maturity were found for walking, prone, and supine, with the DD and Autism-No Regression groups both showing later developing motor maturity than typical children. The only statistically significant differences in movement abnormalities were in the DD group; the two autism groups did not differ from the typical group in rates of movement abnormalities or lack of protective responses. These findings do not replicate previous investigations suggesting that early motor abnormalities seen on home video can assist in early identification of autism.     

Chronicity of Challenging Behaviours in People with Severe Intellectual Disabilities and/or Autism: A Total Population Sample

The skills, social impairments and challenging behaviours of a total population of 166 children, with severe intellectual disabilities and/or autism, were assessed through interview with the main carers, when the children were under 15 years old (time 1). Twelve years later, 141 of these individuals were re-assessed, using the same measures (time 2). “Abnormal” behaviours tended to reduce with age and were associated with poorer language skills and poorer quality of social interaction. Individuals with most abnormal behaviours at time 1, tended to have most at time 2. Abnormal behaviour at time 2 was predicted by the presence of abnormal behaviour at time 1, poor expressive language at time 1, poor quality of social interaction at time 1 and a diagnosis of autism/autistic continuum at time 1.     

Unusual brain growth patterns in early life in patients with autistic disorder: an MRI study

OBJECTIVE: To quantify developmental abnormalities in cerebral and cerebellar volume in autism. METHODS: The authors studied 60 autistic and 52 normal boys (age, 2 to 16 years) using MRI. Thirty autistic boys were diagnosed and scanned when 5 years or older. The other 30 were scanned when 2 through 4 years of age and then diagnosed with autism at least 2.5 years later, at an age when the diagnosis of autism is more reliable. RESULTS: Neonatal head circumferences from clinical records were available for 14 of 15 autistic 2- to 5-year-olds and, on average, were normal (35.1 +/- 1.3 cm versus clinical norms: 34.6 +/- 1.6 cm), indicative of normal overall brain volume at birth; one measure was above the 95th percentile. By ages 2 to 4 years, 90% of autistic boys had a brain volume larger than normal average, and 37% met criteria for developmental macrencephaly. Autistic 2- to 3-year-olds had more cerebral (18%) and cerebellar (39%) white matter, and more cerebral cortical gray matter (12%) than normal, whereas older autistic children and adolescents did not have such enlarged gray and white matter volumes. In the cerebellum, autistic boys had less gray matter, smaller ratio of gray to white matter, and smaller vermis lobules VI-VII than normal controls. CONCLUSIONS: Abnormal regulation of brain growth in autism results in early overgrowth followed by abnormally slowed growth. Hyperplasia was present in cerebral gray matter and cerebral and cerebellar white matter in early life in patients with autism.     

Effectiveness of a Home Program Intervention for Young Children with Autism

This project evaluated the effectiveness of a TEACCH-based home program intervention for young children with autism. Parents were taught how to work with their preschool autistic child in the home setting, focusing on cognitive, academic, and prevocational skills essential to later school success. To evaluate the efficacy of the program, two matched groups of children were compared, a treatment group and a no-treatment control group, each consisting of 11 subjects. The treatment group was provided with approximately 4 months of home programming and was tested before and after the intervention with the Psychoeducational Profile-Revised (PEP-R). The control group did not receive the treatment but was tested at the same 4-month interval. The groups were matched on age, pretest PEP-R scores, severity of autism, and time to follow-up. Results demonstrated that children in the treatment group improved significantly more than those in the control group on the PEP-R subtests of imitation, fine motor, gross motor, and nonverbal conceptual skills, as well as in overall PEP-R scores. Progress in the treatment group was three to four times greater than that in the control group on all outcome tests. This suggests that the home program intervention was effective in enhancing development in young children with autism.