Quantified multidimensional assessment of autism and other pervasive developmental disorders. Application for bioclinical research

[Validation in Arabic of the Revised Autistic Behavior Summarized Evaluation Scale (BSE-R)]

The Behavioral Summarized Evaluation is a rating scale specifically related to the assessment of autistic behaviors in children and young teenagers with Autism Spectrum Disorder, such as communication, social interaction and interests. It also facilitates progressive recording of the evolution of children with ASD involved in short-term therapeutical studies. In the absence of standardized tools to assess autistic behaviors and effects of therapeutics in Lebanon, the BSE-R validation is an urgent need. The purpose of this study is to validate the BSE-R to the Lebanese population.

METHOD

Specialized translators and clinicians ensured forward and backward translation of the scale into Arabic. The participants consisted of 100 children with ASD, diagnosed upon DSMIV-TR criterion (age range: 35 to 153 months, DS: 28.0). Fifty-eight had intellectual disability (ID). Scores of autism severity as measured by CARS1 (Schopler et al., 1980) varied from 20-58.5. Trained raters on recorded individual and group situations performed BSE-R ratings.

RESULTS

BSE-R for Lebanese was found to have excellent inter-rater reliability. The internal validity highlighted a main factor which describes the severity of core autistic behaviors related to social interactions and communication, and behavioral specificities and particular interests with an internal consistency of 0.91 in a one-to-one setting and 0.92 in group settings. External validity of the scale as measured by correlations with CARS and the age of the children showed that this main factor is essentially determined by ASD severity, not by the severity of ID. It was named "relational deficiency" according to the initial paper of Barthélémy et al. (1997).

CONCLUSION

BSE-R in Arabic is a practical tool, useful to all team members working with ASD children in Lebanon and the Arab countries. It will also allow future research based on reliable tools at an international level.

Behaviour Profiles within a Population of 145 Children with Autism Using the Behaviour Summarized Evaluation Scale

Clinicians and researchers have observed a degree of heterogeneity within the autistic syndrome which suggests different pathophysiological mechanisms. Greater understanding of this heterogeneity was sought by studying more homogeneous subpopulations according to developmental age (DA) within a large population of children with autism. The sample consisted of 145 children with autism (population P), and two subpopulations were determined according to DA criteria: DA < 2 years, population PDA-; DA? 2 years, population PDA+. An original multivariate descriptive statistical method, correspondence analysis, was applied to 13 behavioural data, followed by a classical hierarchical clustering method. In population P, four behaviour profiles were distinguished on the basis of three main functions: auditory perception, imitation and sensorimotility. The study of more homogeneous subpopulations according to DA revealed differences in the factorial structure of both subpopulations. In population PDA+ the main relevant behaviours defining profiles in autism were first abnormal reactivity to auditory stimuli, followed by imitation deficiences. However in population PDA-the main relevant behaviours were first stereotypies, followed by abnormal reactivity to auditory stimuli. Modification of the organization of behaviours in autism according to developmental age is clarified; unlike the auditory perception dimension, imitation and sensorimotor dimensions may be dependent on development. These results thus support the heterogeneity of the autistic syndrome and clarify some aspects of change and continuity in the expression of the disorders contained in this syndrome.

Autism genetics: Methodological issues and experimental design

Autism is a complex neuropsychiatric disorder of developmental origin, where multiple genetic and environmental factors likely interact resulting in a clinical continuum between "affected" and "unaffected" individuals in the general population. During the last two decades, relevant progress has been made in identifying chromosomal regions and genes in linkage or association with autism, but no single gene has emerged as a major cause of disease in a large number of patients. The purpose of this paper is to discuss specific methodological issues and experimental strategies in autism genetic research, based on fourteen years of experience in patient recruitment and association studies of autism spectrum disorder in Italy.

Cluster analysis of autistic patients based on principal pathogenetic components

We have recently described four principal pathogenetic components in autism: (I) circadian and sensory dysfunction, (II) immune abnormalities, (III) neurodevelopmental delay, and (IV) stereotypic behaviors. Using hierarchical and k-means clustering, the same 245 patients assessed in our principal component analysis can be partitioned into four clusters: (a) 43 (17.6%) have prominent immune abnormalities accompanied by some circadian and sensory issues; (b) 44 (18.0%) display major circadian and sensory dysfunction, with little or no immune symptoms; (c) stereotypies predominate in 75 (31.0%); and (d) 83 (33.9%) show a mixture of all four components, with greater disruptive behaviors and mental retardation. The "immune" component provides the largest contributions to phenotypic variance (P = 2.7 x 10(-45)), followed by "stereotypic behaviors." These patient clusters may likely differ in genetic and immune underpinnings, developmental trajectories, and response to treatment.

Autism and developmental delay: a comparative clinical study in very young children using IBSE scale

OBJECTIVE

This study improves the knowledge of early autistic symptomatology and research concerning (i) the significant differences in the behaviors of children with autistic disorder (AD) and children with a developmental delay (DD), and (ii) the influence of the cognitive delay on symptomatology.

METHOD

Two groups of 20 young children (7-42 months) were compared: children with AD, and those with DD. The groups were paired by chronological and developmental age. The comparison was extended to four subgroups composed according to age (younger and older children--<24 months, >24 months) and to the global development quotient (GDQ) (the more and less delayed). Each child was evaluated with the Infant Behavior Summarized Evaluation scale (IBSE).

RESULTS

For the younger AD children, significant differences affected social communication and their adaptation to the environment (intolerance to frustration, resistance to change). For the older children (>24 months), this study showed the rapid progression of the number of distinctive signs between AD and DD children according to age and/or developmental level.

CONCLUSIONS

Cognitive delay has an important influence on the symptomatology at the moment of initial recognition of an autistic syndrome. This study is a complement for the fuller understanding of the nature and early diagnosis of disorders specific to autism at the earliest phases of development.

Subtypes of autism by cluster analysis based on structural MRI data

The aim of our study was to subcategorize Autistic Spectrum Disorders (ASD) using a multidisciplinary approach. Sixty four autistic patients (mean age 9.4+/-5.6 years) were entered into a cluster analysis. The clustering analysis was based on MRI data. The clusters obtained did not differ significantly in the overall severity of autistic symptomatology as measured by the total score on the Childhood Autism Rating Scale (CARS). The clusters could be characterized as showing significant differences: Cluster 1: showed the largest sizes of the genu and splenium of the corpus callosum (CC), the lowest pregnancy order and the lowest frequency of facial dysmorphic features. Cluster 2: showed the largest sizes of the amygdala and hippocampus (HPC), the least abnormal visual response on the CARS, the lowest frequency of epilepsy and the least frequent abnormal psychomotor development during the first year of life. Cluster 3: showed the largest sizes of the caput of the nucleus caudatus (NC), the smallest sizes of the HPC and facial dysmorphic features were always present. Cluster 4: showed the smallest sizes of the genu and splenium of the CC, as well as the amygdala, and caput of the NC, the most abnormal visual response on the CARS, the highest frequency of epilepsy, the highest pregnancy order, abnormal psychomotor development during the first year of life was always present and facial dysmorphic features were always present. This multidisciplinary approach seems to be a promising method for subtyping autism.

Medication treatment in subjects with autistic spectrum disorders

Autism is a pervasive developmental disorder that is aetiologically and clinically heterogeneous. Twin and family genetic studies provide evidence for strong genetic components. An international consortium using an affected sib pair strategy has found a promising linkage to a region on chromosome 7. In 10-15 % of the cases autism is due to associated medical conditions that affect normal brain functioning. Post-mortem studies on small case series report cellular abnormalities in the limbic system and cerebellum. Between 10 and 20 % of subjects with autism have macrocephalia, which is in accordance with MRI findings of an increased total brain tissue volume and enlargement most prominent in the occipital and parietal lobes. The most robust and well-replicated neurobiological abnormality in autism is an elevation of whole blood serotonin found in over 30% of the patients. Pharmacological interventions with serotonin reuptake blockers or with atypical neuroleptics that block both dopamine (D2) and serotonin (5-HT2) receptors seem to offer clinical benefit and merit further study.

Autism: current theories regarding its pathogenesis and implications for rational pharmacotherapy

Autism is a pervasive developmental disorder that is aetiologically and clinically heterogeneous. Twin and family-genetic studies provide evidence for strong genetic components. An international consortium using an affected sib pair strategy has found a promising linkage to a region on chromosome 7. In 10 to 15% of cases autism is due to associated medical conditions that affect normal brain functioning. Postmortem studies on small case series report cellular abnormalities in the limbic system and cerebellum. Between 10 and 20% of individuals with autism have macrocephalia, which is in accordance with magnetic resonance imaging (MRI) findings of an increased total brain tissue volume and enlargement most prominent in the occipital and parietal lobes. The most robust and well replicated neurobiological abnormality in autism is an elevation of whole blood serotonin (5-hydroxytryptamine; 5-HT) found in over 30% of patients. Pharmacological interventions with serotonin reuptake inhibitors or with atypical neuroleptics that block both dopamine (D2) and serotonin (5-HT2) receptors seem to offer clinical benefit and merit further study.

Bioclinical profiles of autism and other developmental disorders using a multivariate statistical approach

To study the relationships between clinical and biological data that are necessary for physiopathological analysis in the field of developmental disorders, we developed a quantified grouping system, based on four developmental assessment parameters. Parallel with this clinical research, we developed electrophysiological procedures adapted to the pathology of autism. In this paper, we report the utilization of an original multivariate descriptive statistical approach (correspondence analysis followed by cluster analysis) that allowed us to identify different bioclinical profiles using these clinical and electrophysiological data conjointly. These profiles are believed to be evidence for different underlying cerebral dysfunctions. This procedure proved effective in identifying two main bioclinical dimensions in a population of 145 developmentally disordered children. These dimensions reflect the association of intellectual impairment and centroparietal electrophysiological reactivity on the one hand, and autistic behavior and temporal electrophysiological reactivity on the other. This study, performed on a large population of children using objective methods of data analysis, provides validation of numerous multidisciplinary studies of autism and other developmental disorders carried out on small samples of children.

Validation of the Revised Behavior Summarized Evaluation Scale

The Behavioral Summarized Evaluation scale (BSE), previously published and validated, was developed for the evaluation for the autistic behavior in developmentally disorder children. A revised version of this scale, the Revised Behavior Summarized Evaluation Scale (BSE-R) completed the 20-item BSE scale with the most relevant items extracted from a similar evaluation carried out with very young children. Thus 9 items were added to the original scale concerning nonverbal communication, emotional, and perception areas. This paper reports the reliability and validity studies of this new scale. In addition to confirming the previously published findings concerning the first version of the BSE, new items were extracted from the BSE-R content validity study. They involve fundamental functions such as intention and imitation which open new perspectives for a physiopathological approach to developmental disorders. The BSE-R is a useful tool for progressive recording of the evolution of patients both treated over long periods and included in short-term controlled therapeutic studies.

Serotonin and autism: biochemical and molecular biology features

Whole blood and urinary levels of serotonin (5-hydroxytryptamine; 5-HT) and the derivative urinary 5-hydroxyindoleacetic acid (5-HIAA) were measured in normal and autistic subjects. An association was tested between autism and a marker coding for the 5-HT2A serotonergic receptor gene. Significant group (high urinary 5-HT and low whole blood 5-HT in autism) and age effects (urinary 5-HT decrease with age) were found. Moreover, whole blood 5-HT levels were correlated with clinical state. No differences in allele and genotype frequencies for the 5-HT2A receptor marker were found in this autistic population compared with age-matched healthy students.