WISC-R Subtest But No Overall VIQ–PIQ Difference in Dutch Children with PDD-NOS

Abstract

VIQ-PIQ differences have been studied in children with autism and Asperger syndrome but have not been studied in a separate group of children with PDD-NO, although, PDD-NOS has a much higher prevalence rate than autism and deficits in communication and social interaction are severe. The Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered to 100 children, aged 6-12 years, with PDD-NOS (n = 76), autism (n = 13), and Asperger syndrome (n = 11). PDD-NOS was diagnosed using explicit research criteria. No overall differences between VIQ and PIQ were found in PDD-NOS and autism. Peaks in the subtest scores on Information, Similarities, Picture Arrangement, and Mazes, and troughs in the subtest scores on Comprehension, Digit Span, and Coding were demonstrated in children with PDD-NOS. Their score on the Freedom from Distractibility factor was lower than the scores on the Verbal Comprehension factor and the Perceptual Organization factor. Children with PDD-NOS seemed to have a similar VIQ-PIQ profile as children with autism, and on the subtest level children with PDD-NOS showed some similarities to children with Asperger syndrome or autism. It was not possible to distinguish PDD-NOS from autism or Asperger syndrome by using IQ scores.

Pervasive Developmental Disorder- not Otherwise Specified: Specifying and Differentiating

“…Thus, from a clinical standpoint, children whose PDD-NOS diagnosis was established before 36 months should be re-assessed at a later age (Rondeau et al, 2010). Similar to previous reports (Allen et al, 2001, deBruin et al, 2006, Matson, et al, 2007, Szatmari et al 2002, in our study (Karabekiroglu & Akbas, in press) mental retardation was significantly more prevalent in the autism than in the PDD-NOS or ADHD groups. Several investigators suggested that exploring the presence of mental retardation may be more useful in terms of planning treatment and predicting outcome than a classification based on symptom number alone (Szatmari et al, 2002).…”

Differentiating Among Children with PDD-NOS, ADHD, and those with a Combined Diagnosis on the Basis of WISC-III Profiles

“…The fact that this particular pattern of subtest scores was present in our PDD-NOS group strengthens the credibility of the findings and the accuracy of the PDD-NOS diagnoses. Absolute good performance by PDD-NOS children on Mazes (but not on Block Design this time) was found by De Bruin et al (2006). It can be concluded that in the IQ range of above 70, PDD-NOS children perform better than ADHD children and those with a combined diagnosis, which can primarily be attributed to differences in visuospatial and visuomotor abilities among the groups.…”

“…Up to this date, only two articles described the profiles of cognitive functioning in children with PDD-NOS (De Bruin et al 2006;Koyama et al 2006). The latter of these two also made a comparison with ADHD children.…”

“…The authors found a VIQ \ PIQ pattern in the PDD-NOS group, which corroborated part of the literature on IQ differences in autistic individuals in general (Lincoln et al 1998), while they found the reverse pattern in the children with ADHD, which was a new finding. De Bruin et al (2006) also investigated a group of PDD-NOS children, but they didn't find a VIQ-PIQ discrepancy. These authors also investigated groups of children with autism and Asperger syndrome, respectively, and concluded that is was impossible to distinguish among the three groups on the basis of IQ scores.…”

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

“…But some PDD children are often misdiagnosed with non-PDD conditions, such as attention-deficit-hyperactivity disorder (ADHD). 2 The Wechsler intelligence scales (Wechsler Intelligence Scale for Children [WISC], Wechsler Adult Intelligence Scale [WAIS]) are familiar cognitive tests, and because some of the characteristics have been identified in PDD children, such as a high score on Block Design or a low score on Comprehension, [3][4][5][6][7] information from those subtests may be useful to differentiate PDD children from non-PDD ones. Mayes and Calhoun classified each child's WISC-III profile type by ranking the index and the subtest scores from lowest to highest, and found that low Coding with low Comprehension or low Freedom from Distractibility index with low Comprehension profile correctly identified 56% of children with high-functioning (IQ Ն 80) autism and 76% without autism.…”