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Biomedical subjects

Fred Volkmar

Publications and source records attributed to Fred Volkmar.

At least 19 recordsLinked to original sources
PubMed2005

Three diagnostic approaches to Asperger syndrome: implications for research.

OBJECTIVE: To examine the implications for research of the use of three alternative definitions for Asperger syndrome (AS). Differences across the three nosologic systems were examined in terms of diagnostic assignment, IQ profiles, comorbid symptoms, and familial aggregation of social and other psychiatric symptoms. METHOD: Standard data on diagnosis, intellectual functioning, comorbidity patterns, and family history were obtained on 65 individuals screened for a very high probability of having autism without mental retardation (or higher functioning autism, HFA) or AS. Diagnoses of AS were established based on three different approaches: DSM-IV, presence/absence of communicative phrase speech by 3 years, and a system designed to highlight prototypical features of AS. RESULTS: Agreement between the three diagnostic systems was poor. AS could be differentiated from HFA (but not from PDD-NOS) on the basis of IQ profiles in two of the three systems. Differences in patterns of comorbid symptomatology were obtained in two of the three systems, although differences were primarily driven by the PDD-NOS category. Only one of the approaches yielded differences relative to aggregation of the "broader phenotype" in family members. CONCLUSIONS: Diagnostic assignments of AS based on three commonly used approaches have low agreement and lead to different results in comparisons of IQ profiles, patterns of comorbidity, and familial aggregation of psychiatric symptoms across the approach-specific resultant groups of HFA, AS, and PDD-NOS.

Adolescent↗
PubMed2005

Asperger's syndrome: a comparison of clinical diagnoses and those made according to the ICD-10 and DSM-IV.

The diagnostic criteria for Asperger Syndrome (AS) according to ICD-10 and DSM-IV have been criticized as being too narrow in view of the rules of onset and precedence, whereby autism takes precedence over AS in a diagnostic hierarchy. In order to investigate this further, cases from the DSM-IV multicenter study who had been diagnosed clinically with AS were assigned to appropriate DSM-IV/ICD-10 diagnostic categories. The analysis indicated that 11(23%) cases would be reassigned a diagnosis of autism by either ICD-10 or DSM-IV according to their onset and precedence rules, and 33(68%) would be diagnosed with AS. These results contrast with those of others who have stated that the diagnosis of AS using ICD-10/DSM-IV criteria is 'virtually impossible'. It is suggested that this is due to limitations inherent in these criteria, and alternative conceptualizations are discussed.

Asperger Syndrome↗
PubMed2005

Brief report: relations between prosodic performance and communication and socialization ratings in high functioning speakers with autism spectrum disorders.

Shriberg et al. [Shriberg, L. et al. (2001). Journal of Speech, Language and Hearing Research, 44, 1097-1115] described prosody-voice features of 30 high functioning speakers with autistic spectrum disorder (ASD) compared to age-matched control speakers. The present study reports additional information on the speakers with ASD, including associations among prosody-voice variables and ratings of communication social abilities. Results suggest that the inappropriate sentential stress and hypernasality previously identified in some of these speakers is related to communication/sociability ratings. These findings and associated trends are interpreted to indicate important links between prosodic performance and social and communicative competence. They suggest the need for careful assessment of inappropriate prosody and voice features in speakers with ASD, and for effective intervention programs aimed at reducing the stigmatization of individuals with these conditions.

Adolescent↗
PubMed2005

Autism in infancy and early childhood.

Although initially described as an inborn disorder of affective contact, information on autism as it exists in infants has been limited. Delays in diagnosis, lack of information about the condition, and reliance on retrospective research strategies have been problematic. An awareness of the increased risk for siblings is now allowing the development of new, prospective approaches. Consistent with Kanner's original hypothesis, the available information strongly suggests a fundamental difficulty in the earliest social processes, which, in turn, impacts many other areas of development. New approaches to screening have lowered the age of initial diagnosis; this presents new challenges for early intervention. Directions for future research are highlighted.

Autistic Disorder↗
PubMed2004

Brief report: parental reporting of regression in children with pervasive developmental disorders.

Information on age and nature of the onset of autism and other developmental disorders was obtained through review of parent completed developmental history; in addition information on the child's early development, diagnostic information, and information on parent characteristics was also obtained. In this relatively large series of cases the parents of children with autism were more likely than parents of children with other developmental disorders to report possible loss of developmental skills. However, the question of actual skill loss was complicated since in some cases parents also had reported even earlier developmental delays or a pattern more of developmental stagnation than clear loss of abilities. Only a few children exhibited a clear and unequivocal loss of developmental skills.

Child↗
PubMed2004

Interrelationship between Autism Diagnostic Observation Schedule-Generic (ADOS-G), Autism Diagnostic Interview-Revised (ADI-R), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) classification in children and adolescents with mental retardation.

The interrelationship between the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule-Generic (ADOS-G) and clinical classification was studied in 184 children and adolescents with Mental Retardation (MR). The agreement between the ADI-R and ADOS-G was fair, with a substantial difference between younger and older children (5-8 vs. 8+ years). Compared with the Diagnostic and Statistical Manual of Mental Disorders-IV-TR (DSM-IV-TR) classification of Autistic Disorder (AD) and Pervasive Developmental Disorder (PDD), both instruments measure AD or PDD validly and reliably. Even in low-functioning children the interrelationship between the instruments and the clinical classification was satisfactory. The combination of ADI-R and ADOS-G identifies AD or PDD, as described in the DSM-IV-TR, most appropriately. Both instruments seem to be of great value in the diagnostic process of PDD in children and adolescents with MR.

Adolescent↗
PubMed2004

Adaptive behavior in autism and Pervasive Developmental Disorder-Not Otherwise Specified: microanalysis of scores on the Vineland Adaptive Behavior Scales.

The purpose of this study is to provide a microanalysis of differences in adaptive functioning seen between well-matched groups of school-aged children with autism and those diagnosed as having Pervasive Developmental Disorder-Not Otherwise Specified, all of whom functioned in the mild to moderate range of intellectual impairment. Findings indicate that the major area of difference between children with autism and those with Pervasive Developmental Disorder-Not Otherwise Specified, was expressive communication; specifically, the use of elaborations in syntax and morphology and in pragmatic use of language to convey and to seek information in discourse. Linear discriminant function analysis revealed that scores on just three of these expressive communication item sets correctly identified subjects in the two diagnostic categories with 80% overall accuracy. Implications of these findings for both diagnosis and intervention with children with Autism Spectrum Disorders will be discussed.

Activities of Daily Living↗
PubMed2003

The enactive mind, or from actions to cognition: lessons from autism.

Normative-IQ individuals with autism are capable of solving explicit social cognitive problems at a level that is not matched by their ability to meet the demands of everyday social situations. The magnitude of this discrepancy is now being documented through newer techniques such as eye tracking, which allows us to see and measure how individuals with autism search for meaning when presented with naturalistic social scenes. This paper offers an approach to social cognitive development intended to address the above discrepancy, which is considered a key element for any understanding of the pathophysiology of autism. This approach, called the enactive mind (EM), originates from the emerging work on 'embodied cognitive science', a neuroscience framework that views cognition as bodily experiences accrued as a result of an organism's adaptive actions upon salient aspects of the surrounding environment. The EM approach offers a developmental hypothesis of autism in which the process of acquisition of embodied social cognition is derailed early on, as a result of reduced salience of social stimuli and concomitant enactment of socially irrelevant aspects of the environment.

Autistic Disorder↗
PubMed2003

Adaptive skills.

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed2003

Measuring pervasive developmental disorders in children and adolescents with mental retardation: a comparison of two screening instruments used in a study of the total mentally retarded population from a designated area.

The performance of two screening instruments for Pervasive Developmental Disorders was studied in the total population of participants with mental retardation between 4 and 18 years (n = 1059) in Friesland, a northern province of the Netherlands. Parents completed the Autism Behavior Checklist (ABC), staff completed the Scale of Pervasive Developmental Disorder in Mentally Retarded Persons (PDD-MRS). The screening instruments were related to the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule-Generic for 184 participants. The agreement between ABC and PDD-MRS was fair (kappa = .24). The ABC had a better criterion-related validity compared with the Autism Diagnostic Interview-Revised, and the PDD-MRS compared to the Autism Diagnostic Observation Schedule-Generic. However, related to the clinical classification, both instruments performed equally well. Concluding, the ABC and PDD-MRS partially identify the same cases related to external criteria. In addition, each instrument has its own contribution. Both instruments are valuable in detecting children who are at high risk for PDD.

Adolescent↗
PubMed2003

Annotation: Hyperlexia: disability or superability?

BACKGROUND: Hyperlexia is the phenomenon of spontaneous and precocious mastery of single-word reading that has been of interest to clinicians and researchers since the beginning of the last century. METHODS: An extensive search of publications on the subject of hyperlexia was undertaken and all available publications were reviewed. RESULTS: The literature can be subdivided into discussions of the following issues: (1) whether hyperlexia is a phenomenon that is characteristic only of specific clinical populations (e.g., children with developmental delays) or whether it can also be observed in the general population; (2) whether hyperlexia is a distinct syndrome comorbid with a number of different disorders or whether it is a part of the spectrum of some other clinical condition(s); (3) whether hyperlexia should be defined through single-word reading superiority with regard to reading comprehension, vocabulary, general intelligence, any combination of the three, or all three characteristics; (4) whether there is a specific neuropsychological profile associated with hyperlexia; (5) whether hyperlexia is characterized by a particular developmental profile; and (6) whether hyperlexia should be viewed as a disability (deficit) or superability (talent). CONCLUSIONS: We interpret the literature as supporting the view that hyperlexia is a superability demonstrated by a very specific group of individuals with developmental disorders (defined through unexpected single-word reading in the context of otherwise suppressed intellectual functioning) rather than as a disability exhibited by a portion of the general population (defined through a discrepancy between levels of single-word reading and comprehension). We simultaneously argue, however, that multifaceted and multi-methodological approaches to studying the phenomenon of hyperlexia, defined within the research framework of understanding single-word reading, are warranted and encouraged.

Adolescent↗
PubMed2002

Risperidone in children with autism and serious behavioral problems.

BACKGROUND: Atypical antipsychotic agents, which block postsynaptic dopamine and serotonin receptors, have advantages over traditional antipsychotic medications in the treatment of adults with schizophrenia and may be beneficial in children with autistic disorder who have serious behavioral disturbances. However, data on the safety and efficacy of atypical antipsychotic agents in children are limited. METHODS: We conducted a multisite, randomized, double-blind trial of risperidone as compared with placebo for the treatment of autistic disorder accompanied by severe tantrums, aggression, or self-injurious behavior in children 5 to 17 years old. The primary outcome measures were the score on the Irritability subscale of the Aberrant Behavior Checklist and the rating on the Clinical Global Impressions - Improvement (CGI-I) scale at eight weeks. RESULTS: A total of 101 children (82 boys and 19 girls; mean [+/-SD] age, 8.8+/-2.7 years) were randomly assigned to receive risperidone (49 children) or placebo (52). Treatment with risperidone for eight weeks (dose range, 0.5 to 3.5 mg per day) resulted in a 56.9 percent reduction in the Irritability score, as compared with a 14.1 percent decrease in the placebo group (P<0.001). The rate of a positive response, defined as at least a 25 percent decrease in the Irritability score and a rating of much improved or very much improved on the CGI-I scale, was 69 percent in the risperidone group (34 of 49 children had a positive response) and 12 percent in the placebo group (6 of 52, P<0.001). Risperidone therapy was associated with an average weight gain of 2.7+/-2.9 kg, as compared with 0.8+/-2.2 kg with placebo (P<0.001). Increased appetite, fatigue, drowsiness, dizziness, and drooling were more common in the risperidone group than in the placebo group (P<0.05 for each comparison). In two thirds of the children with a positive response to risperidone at eight weeks (23 of 34), the benefit was maintained at six months. CONCLUSIONS: Risperidone was effective and well tolerated for the treatment of tantrums, aggression, or self-injurious behavior in children with autistic disorder. The short period of this trial limits inferences about adverse effects such as tardive dyskinesia.

Adolescent↗
PubMed2002

Visual fixation patterns during viewing of naturalistic social situations as predictors of social competence in individuals with autism.

BACKGROUND: Manifestations of core social deficits in autism are more pronounced in everyday settings than in explicit experimental tasks. To bring experimental measures in line with clinical observation, we report a novel method of quantifying atypical strategies of social monitoring in a setting that simulates the demands of daily experience. Enhanced ecological validity was intended to maximize between-group effect sizes and assess the predictive utility of experimental variables relative to outcome measures of social competence. METHODS: While viewing social scenes, eye-tracking technology measured visual fixations in 15 cognitively able males with autism and 15 age-, sex-, and verbal IQ-matched control subjects. We reliably coded fixations on 4 regions: mouth, eyes, body, and objects. Statistical analyses compared fixation time on regions of interest between groups and correlation of fixation time with outcome measures of social competence (ie, standardized measures of daily social adjustment and degree of autistic social symptoms). RESULTS: Significant between-group differences were obtained for all 4 regions. The best predictor of autism was reduced eye region fixation time. Fixation on mouths and objects was significantly correlated with social functioning: increased focus on mouths predicted improved social adjustment and less autistic social impairment, whereas more time on objects predicted the opposite relationship. CONCLUSIONS: When viewing naturalistic social situations, individuals with autism demonstrate abnormal patterns of social visual pursuit consistent with reduced salience of eyes and increased salience of mouths, bodies, and objects. Fixation times on mouths and objects but not on eyes are strong predictors of degree of social competence.

Adolescent↗
PubMed2002

A descriptive study of hyperlexia in a clinically referred sample of children with developmental delays.

In this study, we evaluated the incidence of hyperlexia in a clinically referred sample of 80 children with developmental delays. Based on hypotheses previously formulated in the literature, the study investigated the frequency of hyperlexia among boys and girls, the incidence of hyperlexia in children with Pervasive Developmental Disorders (PDD)-spectrum compared with non-PDD diagnoses, the range of IQ and of various cognitive skills in children with and without hyperlexia, and the developmental outcomes of children with and without hyperlexia. The results revealed no significant differences in the frequency of hyperlexia in girls compared with boys. However, the frequency of hyperlexia was significantly elevated among children with PDD compared with children with non-PDD diagnoses. The range of IQ and other cognitive skills and the developmental outcomes of children with hyperlexia were comparable to those of children without hyperlexia.

Child↗