Wechsler IQ profiles in diagnosis of high-functioning autism

A Wechsler Intelligence Scale profile characterized by VIQ < PIQ with lowest subtest score on Comprehension and highest on Block Design has been associated with autism. Recently, this profile has been applied to assess the accuracy of diagnosis in research samples and for differentiating autism from similar disorders in high-functioning individuals. Universality of this profile, however, has not been sufficiently demonstrated. We therefore examined WISC-R and WAIS-R profile characteristics in 81 rigorously diagnosed high-functioning (VIQ and FSIQ > 70) children (n=45) and adults (n=36) with autism. Analysis of the profiles in these groups did not reveal the presumed typical VIQ < PIQ pattern. The typical subtest pattern was found, but the magnitude of profile variability was small We concluded that individuals with autism can demonstrate a wide range of ability levels and patterns on the Wechsler scales, without a single characteristic prototype. Use of IQ score profiles in the diagnosis and differential diagnosis of autism in high-functioning individuals is not considered valid.This work was supported by National Institute of Mental Health Grant MH40858 and NINDS James A. Shannon Director's Award to Nancy J. Minshew. Acknowledgment is also expressed to the Department of Veterans Affairs for support of this research.     

Executive dysfunction in treated phenylketonuric patients

Objectives  Executive function deficits have been described in early and continuously treated patients with phenylketonuria (PKU). The aim of this study was to examine performance on executive function tasks of treated patients with PKU diagnosed by 2 years of age. Patients and methods  Ten patients with PKU and normal intelligence score who were diagnosed before the age of 2 years and subsequently treated continuously, were compared with 15 typically developing control children on a battery of neuropsychological tests, including the tower of London (TOL), continuous performance test (CPT), and Stroop test. Results  PKU cases showed significantly poorer performance on the TOL task compared to the control group with the difference being significant in the first three levels of the test. With the CPT, PKU cases had significantly more omission errors than control subjects. On the Stroop test there was no statistically significant difference between the groups. No significant correlation was found between the concurrent serum phenylalanine (Phe) level and results of the executive tests in PKU patients. Conclusion  This study identified executive dysfunction in early-treated PKU patients with normal IQ, particularly in the planning and attention domains. Further studies are required to compare the results with those from other neurodevelopmental disorders such as ADHD and autism, to establish whether the pattern of findings is specific to PKU.     

Broader Autism Phenotype in Parents of Autistic Children: Reality or Myth?

The finding that relatives of individuals with autism show mild autistic traits is referred to as the broader autism phenotype (BAP). In the current study, 25 parents with a child with high-functioning autism and 25 parents with typically developed children were compared on: (1) the Block Design Test, (2) the Autism-Spectrum Quotient (AQ), and (3) a reaction time task to examine reflexive covert visual orienting to social (eyes) and non-social (arrows) cues. The parent groups were scored similar on the Block Design Test and the AQ. However, fathers with an autistic child demonstrated a different reaction time pattern and responded slower on the social cues than control fathers. These results partly support and further elaborate on the BAP in parents with an autistic child.     

Brief Report: The Use of WAIS-III in Adults with HFA and Asperger Syndrome

The WAIS III was administered to 16 adults with high functioning autism (HFA) and 27 adults with Asperger syndrome. Differences between Verbal Intelligence (VIQ) and Performance Intelligence (PIQ) were not found. Processing Speed problems in people with HFA appeared. At the subtest level, the Asperger syndrome group performed weak on Digit Span. Comprehension and Block Design were relative strengths. In the HFA group, performance on Digit-Symbol Coding and Symbol Search was relatively poor. Strengths were found on Information and Matrix Reasoning. The results suggest that the VIQ-PIQ difference cannot distinguish between HFA and Asperger syndrome. WAIS III Factor Scale and Subtest patterning provides a more valid indicator.     

Analysis of WISC-III,Stanford-Binet:IV,and academic achievement test scores in children with autism

Nonverbal IQs were greater than verbal IQs for young children (3–7 years of age) on the Stanford-Binet:IV (n = 53). However, WISC-III verbal and nonverbal IQs were similar for older children, 6–15 years of age (n = 63). Stanford-Binet:IV profiles were generally consistent for the low-IQ (<80) and high-IQ (80) groups, with high scores on visual matching tests (Bead Memory and Quantitative Reasoning). The low- and high-WISC-III IQ groups both performed well relative to IQ on tests of lexical knowledge (Similarities, Information, and Vocabulary), but not on language comprehension and social reasoning (Comprehension). The low-IQ group did best on visuo-motor subtests (Object Assembly and Block Design), but the high-IQ group did not. The high-IQ group had significantly low scores on the Digit Span, Arithmetic, Coding, VMI, and WIAT Written Expression tests, suggesting attention and writing weaknesses.     

Onset Patterns Prior to 36 Months in Autism Spectrum Disorders

The present study investigated differences among children with three different patterns of autism symptom onset: regression, plateau, and no loss and no plateau. Cross-sectional data were collected from parents of children aged 3–17 years with an autism spectrum disorder (n = 2,720) who were recruited through a US-based online research database. Parental report of developmental characteristics was assessed through a parent questionnaire, and current autism symptoms were measured via the Social Responsiveness Scale and Social Communication Questionnaire. Multivariate analyses indicated that children with regression had a distinct developmental pattern marked by less delayed early development. However, following regression, these children evinced elevated autism symptom scores and an increased risk for poorer outcomes when compared with the other onset groups.     

Local processing and social skills in children with Autism Spectrum Disorders: The role of anxiety and cognitive functioning

The present study examined the relations between anxiety, cognitive functioning, local processing, and social skills in a group of 102 children diagnosed with an Autism Spectrum Disorder. The results indicated that children diagnosed with Asperger's Disorder had significantly higher cognitive functioning and enhanced local processing (i.e., Block Design scores) compared to those diagnosed with Autistic Disorder or PDD-NOS. Regression analyses results showed that anxiety and cognitive functioning moderated the association between local processing and social skills. For children with low cognitive functioning and high anxiety, greater local processing was associated with poorer social skills than those with high cognitive functioning, high anxiety, and greater local processing. For children with high cognitive functioning and high anxiety, enhanced local processing was associated with better social skills than those with high cognitive functioning and reduced local processing. Implications of these findings are discussed.     

Autism and phenylketonuria

Phenylketonuria (PKU) has been also reported in children with infantile autism (IA); however, the frequency of this association is variably reported. Patients with various forms of hyperphenylalaninemia (HPA) were evaluated applying two methods: the Autism Diagnostic Interview-Revised (ADI-R) and the Childhood Autism Rating Scale (CARS). A total of 243 patients were investigated, 97 with classical PKU, 62 identified by neonatal screening, and 35 late diagnosed. None out of 62 patients with classic PKU diagnosed early met criteria for autism. In the group of 35 patients diagnosed late, two boys (5.71%) ages 16 and 13 years fulfilled the diagnostic criteria for autism. The present study confirms that classical PKU is one of the causes of autism, but the prevalence seems to be very low.     

The relationship of working memory, inhibition, and response variability in child psychopathology

INTRODUCTION: The aim of this study was to investigate the relationship between working memory and inhibition in children with attention deficit hyperactivity disorder (ADHD), high-functioning autism (HFA), and Tourette syndrome (TS), compared to normally developing children. Furthermore, the contribution of variation in processing speed on working memory and inhibition was investigated in these childhood psychopathologies. METHOD: Four groups of children are reported in this study: 65 children with ADHD, 66 children with HFA, 24 children with TS, and 82 normal control children. All children were in the age range of 6-13 years. RESULTS: The relationship between working memory and inhibition was similar in children with ADHD, HFA, TS, and normally developing children. The relationship between both domains did not alter significantly for any of the groups, when variation in processing speed was taken into account. More symptoms of hyperactivity/impulsivity are related to a poorer inhibitory process and greater response variability. More symptoms of autism are related to a poorer working memory process. CONCLUSION: The current study showed that working memory, inhibition, and response variability, are distinct, but related cognitive domains in children with developmental psychopathologies. Research with experimental manipulations is needed to tackle the exact relationship between these cognitive domains.     

Cognitive profile difference between normally intelligent children with Asperger's disorder and those with pervasive developmental disorder not otherwise specified

Aim: Asperger's disorder (Asperger syndrome, AS) and pervasive developmental disorder not otherwise specified (PDD‐NOS) are different subtypes of mild pervasive developmental disorders (PDD). Methods: Using the Japanese version of the Wechsler Intelligence Scale for Children–Third Edition (WISC‐III), 28 AS children (mean age, 9.3 years, 24 male) were compared with 78 PDD‐NOS children (mean age, 7.6 years, 64 male) with normal intelligence (IQ ≥ 85), using analysis of covariance (ancova ) with the chronological age of a child as a covariate. Results: Verbal IQ tended to be higher in the AS children than in the PDD‐NOS children (mean raw scores, AS vs PDD‐NOS: 103.9 vs 99.6; P < 0.10), although full‐scale and performance IQ did not differ significantly. Compared with the PDD‐NOS children, the AS children scored significantly higher on Freedom from Distractibility index (110.1 vs 104.5; P < 0.05) consisting of Arithmetic (11.0 vs 9.9, P = 0.04) and Digit Span (12.4 vs 11.6, P = 0.051), but tended to score lower on Coding (8.5 vs 9.8, P = 0.08). Conclusion: The typical cognitive profile of PDD (i.e. low score on Comprehension and high score on Block Design) was shared by both groups, which may support the validity of the current diagnostic classification of PDD. Relatively better verbal ability in AS children seems to reflect their normal language acquisition in infancy, and strong numeric interest may produce the AS children's mathematical excellence over PDD‐NOS children. A low score on Coding in AS children might reflect their extreme slowness, circumstantiality and/or drive for perfection.     

Big heads, small details and autism

Autism is thought to be associated with a bias towards detail-focussed processing. While the cognitive basis remains controversial, one strong hypothesis is that there are high processing costs associated with changing from local into global processing. A possible neural mechanism underlying this processing style is abnormal neural connectivity; specifically reduced structural or functional connectivity between brain regions might lead to good exemplar-based processing but poor generalisation. Abnormal neural connectivity has also been suggested to account for the increased incidence of macrocephaly in autism (increased head/brain size). The present study therefore investigated the effect of head size on the ability to switch between global and local processing in autism. 49 high-functioning 7-12 year olds with autism (12 with macrocephaly) were compared to 25 normally developing children in their performance on a Local-Global Switching task. Those children with autism who also had macrocephaly showed a greater processing cost when switching into global processing, or ‘zooming out’, than both the remaining children with autism and the control children. A second experiment revealed that macrocephaly in the context of normal development is not associated with difficulty switching into global processing but rather occurs in children who are physically large. Macrocephaly in the context of autism may therefore be a biological marker of abnormal neural connectivity, and of a local processing bias.     

Executive dysfunction in Turkish children at high risk for schizophrenia

Objective  To explore different aspects of executive function (i.e. sequencing, set shifting and mental flexibility) in children who are at high risk for schizophrenia by comparing them with normal controls. Method  The high risk (HR) group consisted of 30 children whose parents were diagnosed as schizophrenia. As the control group (CG) 30 children, whose parents did not meet any DSM IV diagnostic criteria for any psychiatric disorder, participated. They were age and sex matched with the HR group. For the evaluation of different domains of cognitive functions Wechsler intelligence scale for children-revised (WISC-R), and a group of neuropsychological tests, including Trail Making A-B Tests, Color Form Test, and Progressive Figures Test were administered. Behavioral problems were assessed using Hacettepe Adjustment Scale. Results  The subjects in the high risk group had significantly lower scores on Trail Making A-B, Color Form, Progressive Figures Tests, as well as subtests and scores of WISC-R (Information, Comprehension, Similarities, Picture Completion, Block Design, Object Assembly and Coding subtests, Verbal, Performance and Full Scale IQ scores). There is no significant difference between the two groups in the frequency and severity of behavioral problems. Conclusion  Children of parents with schizophrenia displayed significantly greater number of difficulties in several areas of executive function, such as sequencing, set shifting, and mental flexibility, when compared to their controls.     

Dyspraxia in autism: association with motor, social, and communicative deficits

Impaired performance of skilled gestures, referred to as dyspraxia, is consistently reported in children with autism; however, its neurological basis is not well understood. Basic motor skill deficits are also observed in children with autism and it is unclear whether dyspraxia observed in children with autism can be accounted for by problems with motor skills. Forty-seven high-functioning children with an autism spectrum disorder (ASD), autism, or Asperger syndrome (43 males, four females; mean age 10y 7m [SD 1y 10m], mean Full-scale IQ (FSIQ) 99.4 [SD 15.9]), and 47 typically developing (TD) controls (41 males, six females; mean age 10y 6m [SD 1y 5m], mean FSIQ 113.8 [SD 12.3], age range 8-4y) completed: (1) the Physical and Neurological Assessment of Subtle Signs, an examination of basic motor skills standardized for children, and (2) a praxis examination that included gestures to command, to imitation, and with tool-use. Hierarchical regression was used to examine the association between basic motor skill performance (i.e. times to complete repetitive limb movements) and praxis performance (total praxis errors). After controlling for age and IQ, basic motor skill was a significant predictor of performance on praxis examination. Nevertheless, the ASD group continued to show significantly poorer praxis than controls after accounting for basic motor skill. Furthermore, praxis performance was a strong predictor of the defining features of autism, measured using the Autism Diagnostic Observation Schedule, and this correlation remained significant after accounting for basic motor skill. Results indicate that dyspraxia in autism cannot be entirely accounted for by impairments in basic motor skills, suggesting the presence of additional contributory factors. Furthermore, praxis in children with autism is strongly correlated with the social, communicative, and behavioral impairments that define the disorder, suggesting that dyspraxia may be a core feature of autism or a marker of the neurological abnormalities underlying the disorder.     

Association between intellectual functioning and age in children and young adults with Duchenne muscular dystrophy: further results from a meta-analysis

This study used meta-analytical techniques to explore the association between intelligence and age in children with Duchenne muscular dystrophy (DMD). The sample comprised 1224 children and young adults with DMD (mean age 12 y 3 mo, SD 4 y; range 2 y to 27 y). Standardized measures including the Wechsler Intelligence Scales (WIS) and the Stanford-Binet Intelligence Scales were used to estimate intelligence. No age-related difference was noted for Full-scale and Performance intelligence quotients (IQ). However, Verbal IQ increased significantly with age. Age-related increases were noted for the WIS Information, Similarities, Arithmetic, Comprehension, Digit Span, Picture Arrangement, Block Design, and Coding subscales. These results support the notion that younger children with DMD have deficits in verbal reasoning and verbal processing. Older children with DMD, particularly those of 14 years and older, were less likely to present with these problems. Implications of these findings and possible future research directions are discussed.     

Predicting children with pervasive developmental disorders using the Wechsler Intelligence Scale for Children-Third Edition

An original combination score (i.e. the sum of Vocabulary and Comprehension subtracted from the sum of Block Design and Digit Span) was created from the four Wechsler Intelligence Scale for Children–Third Edition (WISC-III) subtests identified by discriminant analysis on WISC-III data from 139/129 children with/without pervasive developmental disorders (PDD; mean, 8.3/8.1 years) and its utility examined for predicting PDD. Its best cut-off was 2/3, with sensitivity, specificity, positive and negative predictive values of 0.68, 0.61, 0.65 and 0.64, respectively. The score seems useful, so long as clinicians are aware of its limitations and use it only as a supplemental measure in PDD diagnosis.     

Morphological Features in Children with Autism Spectrum Disorders: A Matched Case–Control Study

This study was designed to examine morphological features in a large group of children with autism spectrum disorder versus normal controls. Amongst 421 patients and 1,007 controls, 224 matched pairs were created. Prevalence rates and odds ratios were analyzed by conditional regression analysis, McNemar test or paired t-test matched pairs. Morphological abnormalities were significantly more prevalent in patients with autism than in the normal control group and 48 morphological features distinguished patients from controls. Our findings show that morphological features are associated with autism. Exploring potential underlying genetic mechanisms of this association might lead to a better understanding of autism.     

Disruptive Mood Dysregulation Disorder Symptoms by Age in Autism,ADHD, and General Population Samples

Disruptive mood dysregulation disorder (DMDD) is a controversial DSM-5 diagnosis. It is not known how DMDD symptoms vary by age and if differences are similar for autism, ADHD, and general population samples. Our study analyzed the two DMDD symptoms (irritable-angry mood and temper outbursts) in 1,827 children with autism or ADHD (with or without oppositional defiant disorder/ODD) and 657 general-population children 2–16 years of age. DMDD symptoms were rated by mothers on the Pediatric Behavior Scale. For all age groups, mean DMDD scores were less than sometimes a problem in the general population and ADHD-Inattentive (ADHD-I) samples, greater than sometimes but less than often a problem in autism and ADHD-Combined (ADHD-C), and greater than often a problem in children with autism or ADHD who also had ODD. DMDD symptoms were unrelated to age in children six and older. Preschool children with ADHD-C, ADHD-I, and ODD had more DMDD symptoms than school-age children, but DMDD symptoms did not differ by age in autism. DMDD symptoms were found in 45% of children with autism and were common at all ages. Evidence-based interventions are discussed.     

Age-related working memory impairments in children with prefrontal dysfunction associated with phenylketonuria.

The prefrontal cortex of the brain has been shown to play a crucial role in working memory, and age-related changes in prefrontal function may contribute to the improvements in working memory that are observed during childhood. We examined the developmental trajectory of working memory in school-age children with early-treated phenylketonuria (PKU), a metabolic disorder that results in prefrontal dysfunction. Using a recognition procedure, we evaluated working memory for letters, abstract objects, and spatial locations in 20 children with PKU and 20 typically developing control children. Children in both groups ranged from 6 to 17 years of age. Our findings revealed poorer performance across all three types of materials for children with PKU. In addition, there was a significant difference in the developmental trajectory of working memory for children with PKU as compared with controls. Specifically, deficits were not apparent in younger children with PKU. Instead, deficits were observed only in older children, suggesting the presence of a developmental deficit rather than a developmental delay in the working memory of children with PKU.     

Sex Differences in WISC-III Profiles of Children with High-functioning Pervasive Developmental Disorders

Using the Japanese version of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III), 26 girls with high-functioning (IQ ≥ 70) pervasive developmental disorders (HFPDD) (mean age, 8.2 years) were compared with 116 boys with HFPDD (mean age, 9.0 years). Compared with the boys, the girls scored significantly higher on the Processing Speed index, Coding, and Symbol Search, but scored significantly lower on Block Design. Although both groups showed weakness on Comprehension in the verbal domain, the girls’ subtest profile in the performance domain was relatively even and significantly different from the boys’, which was characterized by a peak on Block Design. Such differences should be replicated, and possible behavioral, neurological, and genetic links to these sex differences should be clarified.     

Interpreter-Mediated Neuropsychological Testing of Monolingual Spanish Speakers

The primary objective of this study was to investigate empirically whether using an interpreter to conduct neuropsychological testing of monolingual Spanish speakers affects test scores. Participants included 40 neurologically normal Spanish speakers with limited English proficiency, aged 18–65 years (M?=?39.7, SD?=?13.9), who completed the Vocabulary, Similarities, Block Design, and Matrix Reasoning subtests of the Wechsler Adult Intelligence Scale-III in two counterbalanced conditions: with and without an interpreter. Results indicated that interpreter use significantly increased scores on Vocabulary and Similarities. However, scores on Block Design and Matrix Reasoning did not differ depending on whether or not an interpreter was used. In addition the findings suggested a trend toward higher variability in scores when an interpreter was used to administer Vocabulary and Similarities; this trend did not show up for Block Design or Matrix Reasoning. Together the results indicate that interpreter use may significantly affect scores for some tests commonly used in neuropsychological practice, with this influence being greater for verbally mediated tests. Additional research is needed to identify the types of tests that may be most affected as well as the factors that contribute to the effects. In the meantime neuropsychologists are encouraged to avoid interpreter use whenever practically possible, particularly for tests with high demands on interpreter abilities and skills, with tests that have not been appropriately adapted and translated into the patient's target language, and with interpreters who are not trained professionals.