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Biomedical subjects

Fred R Volkmar

Publications and source records attributed to Fred R Volkmar.

At least 19 recordsLinked to original sources
PubMed2006

Social and communication abilities and disabilities in higher functioning individuals with autism spectrum disorders: the Vineland and the ADOS.

The relationship between adaptive functioning (ability) and autism symptomatology (disability) remains unclear, especially for higher functioning individuals with autism spectrum disorder (ASD). This study investigates ability and disability using the Vineland and Autism Diagnostic Observation Schedule (ADOS), respectively, in two clinical samples of children with ASD. Participants included 187 males with VIQ > 70. Vineland scores were substantially below VIQ, highlighting the magnitude of adaptive impairments despite cognitive potential. A weak relationship was found between ability and disability. Negative relationships were found between age and Vineland scores and no relationships were found between age and ADOS scores. Positive relationships were found between IQ and Vineland Communication. Results stress the need for longitudinal studies on ability and disability in ASD and emphasize the importance of adaptive skills intervention.

Adolescent↗
PubMed2006

Educational placements and service use patterns of individuals with autism spectrum disorders.

This project was undertaken to identify child characteristics associated with educational placement and service use in high-functioning children with autism spectrum disorders. The sample of 101 (nine females) had a mean age of 12 +/- 3 years (mean IQ = 101.77 +/- 19.50). Results indicate that lower-cognitive ability and communication skill were associated with placement in special education. Based on parent-report, most students stayed in the same placement (regular or special education) in which they began first grade and the majority of students received special services in their schools (most often speech/language intervention). Findings highlight the emphasis placed on certain child characteristics (e.g., cognitive ability), with far less emphasis on other areas (e.g., degree of social deficit), in educational placement and service provision.

Adolescent↗
PubMed2006

Placental trophoblast inclusions in autism spectrum disorder.

BACKGROUND: Microscopic examination of placental tissue may provide a route to assessing risk and understanding underlying biology of autism. METHODS: Occurrence of a distinctive microscopic placental morphological abnormality, the trophoblast inclusion, was assessed using archived placental tissue. The rate of occurrence of trophoblast inclusion-positive slides observed for 13 individuals with autism spectrum disorder (ASD) was compared to the rate in an anonymous consecutive birth cohort. RESULTS: The occurrence of inclusion positive slides was significantly greater in the ASD group compared to the control group (6/27 slides, 22.2% vs. 12/154, 7.8%; Fisher Exact Test, two-tailed p = .033; relative risk 2.85). The proportion of positive cases was also greater in the ASD group (5/13 cases, 38.5% vs. 8/61, 13.1%; Fisher Exact, two-tailed p = .044; relative risk 2.93). Behavioral severity scores did not differ across groups of inclusion positive (N = 4) and negative (N = 8) ASD individuals. CONCLUSIONS: Although probably not functionally detrimental or causative, the greater occurrence of placental trophoblast inclusions observed in ASD individuals may reflect altered early developmental processes. Further research is required to replicate the basic finding, to understand the basis for the trophoblastic abnormality, and to determine the utility of the measure in early detection of ASD.

Adolescent↗
PubMed2006

Is there a 'regressive phenotype' of Autism Spectrum Disorder associated with the measles-mumps-rubella vaccine? A CPEA Study.

A multi-site study of 351 children with Autism Spectrum Disorders (ASD) and 31 typically developing children used caregiver interviews to describe the children's early acquisition and loss of social-communication milestones. For the majority of children with ASD who had experienced a regression, pre-loss development was clearly atypical. Children who had lost skills also showed slightly poorer outcomes in verbal IQ and social reciprocity, a later mean age of onset of autistic symptoms, and more gastrointestinal symptoms than children with ASD and no regression. There was no evidence that onset of autistic symptoms or of regression was related to measles-mumps-rubella vaccination. The implications of these findings for the existence of a 'regressive phenotype' of ASD are discussed.

Autistic Disorder↗
PubMed2006

Familial autoimmune thyroid disease as a risk factor for regression in children with Autism Spectrum Disorder: a CPEA Study.

A multicenter study of 308 children with Autism Spectrum Disorder (ASD) was conducted through the Collaborative Programs of Excellence in Autism (CPEA), sponsored by the National Institute of Child Health and Human Development, to compare the family history of autoimmune disorders in children with ASD with and without a history of regression. A history of regression was determined from the results of the Autism Diagnostic Interview-Revised (ADI-R). Family history of autoimmune disorders was obtained by telephone interview. Regression was significantly associated with a family history of autoimmune disorders (adjusted OR=1.89; 95% CI: 1.17, 3.10). The only specific autoimmune disorder found to be associated with regression was autoimmune thyroid disease (adjusted OR=2.09; 95% CI: 1.28, 3.41).

Autistic Disorder↗
PubMed2006

Healthcare issues for children on the autism spectrum.

PURPOSE OF REVIEW: We provide a summary of issues relevant to healthcare and health delivery in autism and related disorders, with a focus on work published in the past 5 years. RECENT FINDINGS: Autism has a strong genetic basis as evidenced by the high recurrence rate in families and its associations with Fragile X syndrome and tuberous sclerosis. Early diagnosis of autism is important, given the potential for improvement with intervention. Although its associations have been reported with events such as measles-mumps-rubella immunization, large-scale studies have not supported such links. Controlled drug trials have increased in frequency and drug treatment may be helpful in addressing frequently associated behavioural and emotional difficulties. Alternative treatments are frequently preferred by parents. SUMMARY: Knowledge of autism among healthcare professionals has increased but gaps remain. Physicians and other professionals can facilitate the delivery of healthcare services to individuals with autism. Awareness of empirically validated treatments will facilitate work with individuals with autism and related disorders as well as with their families.

Australia↗
PubMed2005

Perception and production of prosody by speakers with autism spectrum disorders.

Speakers with autism spectrum disorders (ASD) show difficulties in suprasegmental aspects of speech production, or prosody, those aspects of speech that accompany words and sentences and create what is commonly called "tone of voice." However, little is known about the perception of prosody, or about the specific aspects of prosodic production that result in the perception of "oddness." The present study examined the perception and production of a range of specific prosodic elements in an experimental protocol involving natural speech among speakers with ASD between 14 and 21 years of age, in comparison with a typical control group. Results revealed ceiling effects limiting interpretation of findings for some aspects of prosody. However, there were significant between-group differences in aspects of stress perception and production. The implications of these findings for understanding prosodic deficits is speakers with autism spectrum disorders, and for future research in this area, are discussed.

Adolescent↗
PubMed2005

Asperger syndrome.

Explore the source record for details and available documents.

Asperger Syndrome↗
PubMed2005

fMRI activation of the fusiform gyrus and amygdala to cartoon characters but not to faces in a boy with autism.

Abnormal hypoactivation in the amygdala and fusiform gyrus, brain areas that participate in face processing and social cognition, has consistently been demonstrated in persons with autism. We investigated activity in these areas in a boy with autism, DD, who had a special interest in "Digimon" cartoon characters. DD individuates Digimon faster than familiar faces and objects, but he individuates familiar faces no faster than objects. In contrast, a typically developing boy with an interest in "Pokemon" cartoon characters is equally fast at individuating faces and Pokemon and faster at individuating faces and Pokemon than objects and Digimon. In addition, using functional magnetic resonance imaging (fMRI), we show that DD activates his amygdala and fusiform gyrus for perceptual discriminations involving Digimon but not for those involving familiar or unfamiliar faces. This pattern of activation is not seen in the typically developing control with an interest in Pokemon or in a second comparison case who has autism but no interest in Digimon. These results have important implications for our understanding of autism, cortical face specialization, and the possible role of the amygdala in the development of perceptual expertise.

Amygdala↗
PubMed2005

Early regression in social communication in autism spectrum disorders: a CPEA Study.

In a multisite study of 351 children with autism spectrum disorders, 21 children with developmental delays, and 31 children with typical development, this study used caregiver interviews (i.e., the Autism Diagnostic Interview-Revised) at the time of entry into other research projects and follow-up telephone interviews designed for this project to describe the children's early acquisition and loss of social-communication milestones. Children who had used words spontaneously and meaningfully and then stopped talking were described by their caregivers as showing more gestures, greater participation in social games, and better receptive language before the loss and fewer of these skills after the loss than other children with autism spectrum disorders. A significant minority of children with autism without word loss showed a very similar pattern of loss of social-communication skills, a pattern not observed in the children with developmental delays or typical development.

Age Factors↗
PubMed2004

Performance on Cambridge Neuropsychological Test Automated Battery subtests sensitive to frontal lobe function in people with autistic disorder: evidence from the Collaborative Programs of Excellence in Autism network.

Recent structural and functional imaging work, as well as neuropathology and neuropsychology studies, provide strong empirical support for the involvement of frontal cortex in autism. The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computer-administered set of neuropsychological tests developed to examine specific components of cognition. Previous studies document the role of frontal cortex in performance of two CANTAB subtests: the Stockings of Cambridge, a planning task, and the Intradimensional/Extradimensional Shift task, a measure of cognitive set shifting. To examine the integrity of frontal functions, these subtests were administered to 79 participants with autism and 70 typical controls recruited from seven universities who are part of the Collaborative Programs of Excellence in Autism network. The two groups were matched on age, sex, and full-scale IQ. Significant group differences were found in performance on both subtests, with the autism group showing deficits in planning efficiency and extradimensional shifting relative to controls. Deficits were found in both lower- and higher-IQ individuals with autism across the age range of 6 to 47 years. Impairment on the CANTAB executive function subtests did not predict autism severity or specific autism symptoms (as measured by the ADI-R and ADOS), but it was correlated with adaptive behavior. If these CANTAB subtests do indeed measure prefrontal function, as suggested by previous research with animals and lesion patients, this adds to the accumulating evidence of frontal involvement in autism and indicates that this brain region should remain an active area of investigation.

Adolescent↗
PubMed2004

Autism and pervasive developmental disorders.

The quantity and quality of research into autism and related conditions have increased dramatically in recent years. Consequently we selectively review key accomplishments and highlight directions for future research. More consistent approaches to diagnosis and more rigorous assessment methods have significantly advanced research, although the boundaries of the 'broader phenotype' remain to be defined and the validity of Asperger's disorder as a discrete syndrome remains controversial. Recent epidemiological studies have shown that Autism Spectrum Disorders are common, but there continues to be debate about the causes of the increase in the frequency with which autism is diagnosed. Psychological research has helped to develop new developmental models for the disorder and there have also been significant advances in the molecular genetics of autism and understanding of the underlying neurobiological processes. Areas important for future research include the study of autism as it first develops, i.e., in infants and very young children, and of specific processes (psychological and neurobiological) which underlie the disorder. Significant challenges lie ahead in evaluating the growing number of treatments for autism and in integrating the results of research into treatment and educational settings.

Autistic Disorder↗
PubMed2003

Autism.

Autism is a disorder characterised by severe difficulties in social interaction and communication, and with unusual behaviours. Once thought of as rare, autism is now recognised as being common. The role of CNS factors in pathogenesis is suggested by high rates of seizure disorder; research has highlighted the role of several specific brain regions in syndrome pathogenesis. Autism is a strongly genetic disorder and probably arises because of multiple genes; recurrence rates in families with one child are high. Early intervention with various techniques is helpful in many cases. Some pharmacological agents may help with certain problematic behaviours but do not address the underlying cause of the disorder.

Adult↗
PubMed2003

Reduced thalamic volume in high-functioning individuals with autism.

BACKGROUND: In this study, specific consideration is given to a role for the thalamus in autism. METHODS: A volumetric analysis of the thalamus was conducted using magnetic resonance imaging, based on segmentation of continuous 1.2 mm(3) coronal images. The sample consisted of 12 high-functioning individuals with autism, mean age of 21.0 years (SD = 10.4) and mean IQ of 106.4 (SD = 18.3). Normal control subjects were selected to match this group; the mean age was 18.1 years (SD = 6.3); mean IQ was 108.8 (SD = 15.6). RESULTS: Unadjusted mean thalamic volume was not significantly different; however, there were significant differences in the relationship between thalamic volume and total brain volume (TBV). The correlation was strong and positive in the control group but statistically nonsignificant in the autism group. Group differences were found when adjustments were made for TBV, achieved by grouping subjects' measurements on this variable using a split median procedure. Mean thalamic volume was significantly reduced in the autism group relative to normal control subjects, specifically within the high TBV group. CONCLUSION: The increase in thalamic volume with increase in TBV was not seen in autism, suggesting underdeveloped connections between cortical and subcortical regions and indicating a need to examine this structure further.

Adolescent↗
PubMed2003

Asperger syndrome: diagnosis and external validity.

This article provides an overview of the history and clinical features of Asperger syndrome and considers guidelines for clinical assessment and treatment. A review of issues related to external validity is provided that points out the limitations of current research and lists several potentially beneficial areas of investigation into the nosologic status of the condition. It concludes with a discussion of the unequivocal need of individuals with severe social disabilities for comprehensive and adequate educational services and other treatments, regardless of the fact that the validity and usefulness of this specific diagnostic concept is far from resolved.

Adolescent↗