Grace T. Baranek

The Screening and Diagnosis of Autistic Spectrum Disorders

The Child Neurology Society and American Academy of Neurology recently proposed to formulate Practice Parameters for the Diagnosis and Evaluation of Autism for their memberships. This endeavor was expanded to include representatives from nine professional organizations and four parent organizations, with liaisons from the National Institutes of Health. This document was written by this multidisciplinary Consensus Panel after systematic analysis of over 2,500 relevant scientific articles in the literature. The Panel concluded that appropriate diagnosis of autism requires a dual-level approach: (a) routine developmental surveillance, and (b) diagnosis and evaluation of autism. Specific detailed recommendations for each level have been established in this document, which are intended to improve the rate of early suspicion and diagnosis of, and therefore early intervention for, autism.

Practice parameter: Screening and diagnosis of autism Report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society

Article abstract Autism is a common disorder of childhood, affecting 1 in 500 children. Yet, it often remains unrecognized and undiagnosed until or after late preschool age because appropriate tools for routine developmental screening and screening specifically for autism have not been available. Early identification of children with autism and intensive, early intervention during the toddler and preschool years improves outcome for most young children with autism. This practice parameter reviews the available empirical evidence and gives specific recommendations for the identification of children with autism. This approach requires a dual process: 1) routine developmental surveillance and screening specifically for autism to be performed on all children to first identify those at risk for any type of atypical development, and to identify those specifically at risk for autism; and 2) to diagnose and evaluate autism, to differentiate autism from other developmental disorders.

Autism During Infancy: A Retrospective Video Analysis of Sensory-Motor and Social Behaviors at 9–12 Months of Age

This retrospective video study explored the usefulness of sensory-motor measures in addition to social behaviors as early predictors of autism during infancy. Three groups included 11 children with autism, 10 with developmental disabilities, and 11 typically developing children. Home videos were edited to obtain a 10-minute cross-section of situations at 9–12 months for each subject. Using interval scoring, raters coded several behavioral categories (i.e., Looking, Affect, Response to Name, Anticipatory Postures, Motor/Object Stereotypies, Social Touch, Sensory Modulation). Nine items, in combination, were found to discriminate the three groups with a correct classification rate of 93.75%. These findings indicate that subtle symptoms of autism are present at 9–12 months, and suggest that early assessment procedures need to consider sensory processing/sensory-motor functions in addition to social responses during infancy. Furthermore, prior to a time that they reported autistic symptoms, caregivers used compensatory strategies to increase the saliency of stimuli in order to engage their children more successfully; these strategies may provide a window for earlier diagnosis.

Efficacy of Sensory and Motor Interventions for Children with Autism

Idiosyncratic responses to sensory stimuli and unusual motor patterns have been reported clinically in young children with autism. The etiology of these behavioral features is the subject of much speculation. Myriad sensory- and motor-based interventions have evolved for use with children with autism to address such issues; however, much controversy exists about the efficacy of such therapies. This review paper summarizes the sensory and motor difficulties often manifested in autism, and evaluates the scientific basis of various sensory and motor interventions used with this population. Implications for education and further research are described.

Neuropsychological profile of autism and the broad autism phenotype

CONTEXT Multiple articles describe a constellation of language, personality, and social-behavioral features present in relatives that mirror the symptom domains of autism, but are much milder in expression. Studies of this broad autism phenotype (BAP) may provide a potentially important complementary approach for detecting the genes causing autism and defining associated neural circuitry by identifying more refined phenotypes that can be measured quantitatively in both affected and unaffected individuals and that are tied to functioning in particular regions of the brain. OBJECTIVE To gain insight into neuropsychological features that index genetic liability to autism. DESIGN Case-control study. SETTING The general community. PARTICIPANTS Thirty-eight high-functioning individuals with autism and parents of autistic individuals, both with and without the BAP (n = 83), as well as control individuals. MAIN OUTCOME MEASURES A comprehensive battery of neuropsychological tasks assessing social cognition, executive function, and global vs local processing strategies (central coherence). RESULTS Both individuals with autism and parents with the BAP differed from controls on measures of social cognition, with performance in the other 2 domains being more similar to controls. CONCLUSIONS Data suggest that the social cognitive domain may be an important target for linking phenotype to cognitive process to brain structure in autism and may ultimately provide insight into the genes involved in autism.

Hyperresponsive sensory patterns in young children with autism, developmental delay, and typical development.

The nature of hyperresponsiveness to sensory stimuli in children with autism, using a new observational measure, the SPA, was examined. Three groups of young participants were assessed (autism, developmental delay, typical). Across all groups, MA was a predictor of hyperresponsiveness, such that aversion to multisensory toys decreased as MA increased. The two clinical groups displayed higher levels of sensory aversion than the typical group. The groups did not differ in the proportion of children habituating to an auditory stimulus; however, nonresponders were more prevalent in the autism group. These findings elucidate developmental influences on sensory features and the specificity of hyperresponsiveness to clinical groups. Implications for understanding pathogenesis, differentiating constructs of hypersensitivity, and planning treatment are discussed.

Sensory features and repetitive behaviors in children with autism and developmental delays.

This study combined parent and observational measures to examine the association between aberrant sensory features and restricted, repetitive behaviors in children with autism (N=67) and those with developmental delays (N=42). Confirmatory factor analysis was used to empirically validate three sensory constructs of interest: hyperresponsiveness, hyporesponsiveness, and sensory seeking. Examining the association between the three derived sensory factor scores and scores on the Repetitive Behavior Scales—Revised revealed the co‐occurrence of these behaviors in both clinical groups. Specifically, high levels of hyperresponsive behaviors predicted high levels of repetitive behaviors, and the relationship between these variables remained the same controlling for mental age. We primarily found non‐significant associations between hyporesponsiveness or sensory seeking and repetitive behaviors, with the exception that sensory seeking was associated with ritualistic/sameness behaviors. These findings suggest that shared neurobiological mechanisms may underlie hyperresponsive sensory symptoms and repetitive behaviors and have implications for diagnostic classification as well as intervention.

The Neural Circuitry Mediating Shifts in Behavioral Response and Cognitive Set in Autism

BACKGROUND Recent studies have suggested that the social and cognitive impairments in autism are associated with neural processing deficits in specific brain regions. However, these studies have primarily focused on neural systems responsible for face processing and social behaviors. Although repetitive, stereotyped behaviors are a hallmark of autism, little is known about the neural mechanisms underlying these behaviors in the disorder. METHODS We used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of shifts in behavioral response and cognitive set in 18 individuals with high-functioning autism and 15 neurotypical control participants. Participants performed a target detection task specifically designed to distinguish shifts in response from shifts in cognitive set. RESULTS Individuals with autism showed lower accuracy on response shifting trials, independent of whether those trials also required a shift in cognitive set. Compared with control subjects, participants with autism showed reduced activation in frontal, striatal, and parietal regions during these trials. In addition, within the autism group, the severity of restricted, repetitive behaviors was negatively correlated with activation in anterior cingulate and posterior parietal regions. CONCLUSIONS These results suggest that executive deficits and, by extension, repetitive behaviors associated with autism might reflect a core dysfunction within the brains executive circuitry.

Tactile Defensiveness in Children with Developmental Disabilities: Responsiveness and Habituation.

Tactile defensiveness (TD) is characterized by behaviors such as rubbing, scratching, negative expressions, withdrawal, or avoidance in response to tactile stimulation. An inhibition deficit has been implied in the literature and is the focus of this study. School-aged children with developmental disabilities were first assessed for level of TD using three measures. Later, the children were presented with a repeated tactile stimulus while engaged in a computer game. Intensity, duration, and latency of the responses were recorded on each trial. It was hypothesized that higher levels of TD would be associated with (a) greater responsiveness and (b) slower habituation rates to the tactile stimulus. Correlations of three separate TD measures and a series of 3×10 (Level of TD by Responsiveness across trials) repeated measures ANOVAs were used to test the two hypotheses. Children who demonstrated higher levels of TD on some of the preliminary measures also showed higher responsiveness in the experimental situation. There was no general habituation effect, and the limited group by trials interactions were not interpretable. We concluded that there is evidence for a differential sensitivity in TD, but not an inhibition deficit. Another significant finding included a negative correlation between TD and developmental age.

Analysis of Social Interaction Gestures in Infants with Autism.

This study analyzes the emergent use of gestures used among 9–12-month-old infants with autism and typical development using retrospective video analysis. The purpose of the present investigation was to examine the frequency, initiation, prompting, and diversity of types of gestures used for social interaction purposes. It was hypothesized that a restricted variety in type(s) of gestures as well as fewer child-initiated gestures and more prompted gestures would be associated with later diagnosis of autism. Logistic regression analysis found that decreased variety in type of gestures used was significantly associated with autism status. Neither number of total gestures nor initiation of gestures (child-initiated vs. prompted) was significantly associated with autism status.